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List of Figures - Thayer School of Engineering at Dartmouth

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1. EndHeader START FUNCTION DESCRIPTION CC CC CC C CK CI CI CI CC C x Kk A A A AA int stop int motor speed lt drive lib gt SYNTAX A DESCRIPTION PARAMETER1 RETURN VALUE KEY WORDS END DESCRIPTION OKCKCKCKCkCkCk I OI KR ke e x kx int stop int motor speed int motor speed increment int k while 1 if motor_speed 0 gt 20 amp amp motor_speed 1 gt 20 amp amp motor_speed 2 gt 20 amp amp motor speed 3 gt 20 costate waitfor DelayMs 40 slower forwards motor speed motor speed increment UpdateMotorOutput end costate end if else if motor speed 0 20 amp amp motor speed 1 lt 20 amp amp motor speed 2 20 amp amp motor speed 3 lt 20 costate waitfor DelayMs 40 faster forwards motor speed motor speed increment UpdateMotorOutput end costate end if else if motor speed 0 5 amp amp motor speed 1 5 D 2 drive lib 178 amp amp motor_speed 2 lt 5 amp amp motor_speed 3 lt 5 costate waitfor DelayMs 40 turn_left motor_speed angle UpdateMotorOutput end costate end if else if motor_speed 2 gt 5 amp amp motor_speed 3 gt 5 amp amp motor speed 0 5 amp amp motor speed 1 2 5 costate waitfor DelayMs 40 turn_right motor_speed angle UpdateMotorOutput end costate end if else for k 0 k lt 4 k m
2. RETURN VALUE bearing in degrees SEE ALSO END DESCRIPTION OCKCKCKCKCkCk kok k Ck kCKCkCkCKCkCkCK Ck kCKCkCkCKCKCkCKCkCkCK Ck kk k kc k k kc k kck ck ck ok ck k kk kk ko x ke x loat gps bearing GPSPosition c GPSPosition d float dist loat bearing pi lon dif lon diflim loat lat c lon c lat d lon d Fh Hh c Hh D 3 gps lib 197 double dummy00 double lat x lat y dista lon x dummy01 lon y pi 3 141592654 lat c c gt lat degrees c gt lat minutes 60 if c gt lat direction S lat c lat c lat c lat c PI 180 lon c c gt lon degrees c gt lon minutes 60 if c gt lon direction E lon c lon c lon c lon c PI 180 lat d d gt lat degrees d gt lat minutes 60 if d gt lat direction S lat d lat d lat d lat d PI 180 lon d d gt lon degrees d gt lon minutes 60 if d gt lon direction E lon d lon qd lon d lon d PI 180 if cos lat c 0 0001 Small number if lat c gt 0 bearing 180 Starting from N pole else bearing 360 dist lon dif lon diflim if lon dif dist GPS EARTH RADIUS Ton c Lon d 0 0000006399 lon diflim 46 Starting from S pole Convert distance to radian if lat c gt lat d bearing end if else beari e else PI ng 0 nd else si lat_x
3. cp 1 cp 1 3rd navigation cycle Cp 2 cp 1 2nd navigation cycle start point cp 1 cp 2 1st navigation cycle Figure 3 11 Startup procedure 1 with Cool Robot pointing south The dimensions for the whole course correction procedure look larger than they are Com pared to the distance to the waypoint the distance for the offset from the track caused by a south pointing at startup is only about 0 5 The second method to proceed during startup is to take the GPS position first and parse it for current point 2 Then the robot will speed up and drive straight ahead for x seconds defined with tm nav and then it will take the current position 1 and start the first navigation cycle as outlined in Figure 3 12 The advantage of the second method is that the robot does not make any useless turns that are wrong because it does not know its heading The idea behind that is that there will be a lot of interruptions forcing the robot to switch the drive mode from wp follow full to high wind speed or high centered As the robot changes its heading in one of the different drive modes it has no precise information on the current bearing without any movement once back in drive mode waypoint following at full speed or partial speed To keep the number of navigation cycles to turn into the desired bearing as small as possible method two is implemented in the naviation algorithm at this point If the robot switc
4. use FS2 LIB use GPS LIB use DRIVE LIB use ANALOGIN LIB use RADIOCOMM E LIB use NAVIGATE LIB The instruction memmap xmem allows the use of extended memory the upper 128kByte of the first flash memory as code space in addition to the regular code space only the lower 128kByte of the first flash This is necessary because the CoolRobot control program in its final version exceeded a size of 128kBytes The first 4 f def ine statements determine some parameters for the file system used FS2 USE PROGRAM FLASH reserves the specified amount of 4096Byte blocks of the first flash for the file system To use parts of the first flash for a file system in the rabbitbios c file XMEM RESERVE SIZE 0x0000L must be changed to for example to XMEM RESERVE SIZE OxF000L to reserve some of the extended memory OxFOOOL equals 61440Bytes This instruction was used with the Jackrabbit RCM3110 that only got the first flash and is not essential anymore since on the RCM3100 256kBytes of second flash are available In the next line the function fs get flash Ix is used to find out the logical ex tend number of the second flash and store it to the parameter LX 2 USE The logical extend is comparable to name or address of the memory device and in our case LX 2 USE 1 since the second flash memory is detected as device number 1 see Figure 6 3 The param 7 1 Definitions libraries
5. alpha PI 180 off track sin alpha dist to basep if dist to wp lt 1 5 dist to basep off bearing bearing to wp curr bearing end if else off_bearing end else if off_bearing gt 180 bearing to bp curr bearing off bearing off bearing 360 end if if off bearing 180 off bearing off bearing 360 end if if off bearing turn lim off bearing turn lim end if if off bearing turn lim off bearing turn lim end if printf gps string is s n in strie only for use with nav curr p2 curr pl store two points with x sec difference for navigation printf off bearing is f n off bearing if off bearing gt 4 off bearing lt 4 off track gt 20 if drive mode 1 turn_full off_bearing function that makes z degree turn end if if drive_mode 2 turn_partial off_bearing function to make z degree turn at 60 speed end if getgps in strie while count invalid GPS inv limit D 4 navigate lib 206 waitfor DelayMs 1000 bh void fuse FS count invalid getgps in strie if gps get position amp curr p2 in strie 0 break if gps_get_position amp curr_p2 in_strie 1 sprintf out_string GPS parsing error n r send_event 5 end if if gps_get_position amp curr_p2 in strie 2 sprintf out_s
6. define IN00 0x00 xx00 00xx xxxx xxxx AINO define IN01 0x04 xx00 01xx xxxx xxxx AIN1 define IN02 0x08 xx00 10xx xxxx xxxx AIN2 define IN03 0x0C 0011 AIN3 define IN04 0x10 0100 AIN4 define INO5 0x14 0101 AIN5 define IN06 0x18 0110 AIN6 define IN07 0x1C 0111 AIN7 define IN08 0x20 1000 AIN8 define IN09 0x24 1001 AIN9 define IN10 0x28 1010 AIN10 define IN11 0x2C 1011 AIN11 define IN12 0x30 1100 AIN12 define IN13 0x34 1101 AIN13 define IN14 0x38 1110 AIN14 define IN15 0x3C 1111 AIN15 Actions definitions T ULL TT const char READ AIN00 WRITE POWER INOO XREF2 const char READ_AINO1 WRITE POWER INO1 XREF2 const char READ_AINO2 WRITE POWER INO2 XREF2 const char READ_AINO3 WRITE POWER INO3 XREF2 const char READ AIN04 WRITE POWER INO4 XREF2 const char READ_AINO5 D 1 analogin lib 168 WRITE POWER INO5 XREF2 const char READ AIN06 WRITE POWER INO6 XREF2 const char READ AIN07 WRITE POWER INO7 XREF2 const char READ AIN08 WRITE POWER INO8 XREF2 const char READ AINOS WRITE POWER INO9 XREF2 const char READ AIN10 WRITE POWER IN10 XREF2
7. if i 2 latitude if gps parse coordinate sentence amp newpos lat degrees D 3 gps lib 193 amp newpos lat minutes return 1 get coordinate failed if i 3 lat direction if sentence N sentence S newpos gt lat direction sentence end if else return 2 if i 4 longitude if gps_parse_coordinate sentence amp newpos lon degrees amp newpos lon minutes return 1 get coordinate failed if i 5 lon direction if sentence W sentence E newpos gt lon_direction sentence end if else return 2 if i 6 speed over ground knots newpos gt sog sentence if i 7 track over ground degrees true for tg 1 tg lt 6 tg togg tg 1 sentence tg newpos tog strtod togg amp dummy else return 1 unknown sentence type return 0 BeginHeader gps_get_utc int gps get utc struct tm newtime char sentence EndHeader D 3 gps lib 194 START FUNCTION DESCRIPTION ACKCkCk ck kCk ck kCckck k NK A ck ck ck k ck k ck k ck ck k ck ck k ck ck ck k ck ck k kc ck k kk k kk gps get utc gps lib SYNTAX int gps get utc struct tm newtime A EYWORDS gps U in NMEA 0183 format RMC sentence RETURN VALUE 0 success 1 parsing error 2 sen
8. ESCRIPTION ACkCkCk ck ck ck ck kk ck k ck ck k ck ck ck ck ck k k ck k k KA AHA int turn left int motor speed int angle drive lib SYNTAX DESCRIPTION PARAMETERI RETURN VALUE KEY WORDS END DESCRIPTION OKCKCKCKCkCKCk ck kCk Ck kCk Ck k ck Ck kck k kc k kck ck kck ck ckok ck ckok kc kok ke ke e x kx int turn left int motor speed int angle if motor_speed 0 gt 100 amp amp motor_speed 3 gt 100 amp amp motor_speed 2 gt angle 100 amp amp motor_speed 1 gt angle 100 motor_speed 2 angle motor_speed 1 angle UpdateMotorOutput end if else if motor_speed 2 lt 100 1 lt 100 amp amp amp amp amp amp else if motor_speed 0 lt motor speed 3 amp amp motor speed motor speed 0 lt 100 angle B B motor speed 3 lt otor speed 0 otor speed 3 4 UpdateMotorOutput end if 100 angl angle angle 100 angle 2 100 angle 2 D 2 drive lib 177 amp amp motor_speed 2 gt angle 2 100 amp amp motor speed 1 angle 2 100 motor_speed 2 angle 2 motor speed 1 angle 2 motor_speed 0 angle 2 motor_speed 3 angle 2 UpdateMotorOutput end if return motor_speed end function L L L LL LT L TL AAT AT BeginHeader stop int stop int motor speed int motor speed increment
9. SBD Network Equipment Micropro ocessor Qe C y End ur Access Value Added Reseller MA p Host System lt Figure 5 1 Example for an IRIDIUM modem application The IRIDIUM System was developed by Motorola in 1980 as a personal communication sys tem for users that need communications access to and from remote areas where no other form of communication is available It consists of 66 operational low altitude satellites grouped into six polar planes of 11 satellites Each of the satellites performs as node of the telephony net work 13 additional satellites act as backup system The satellites circle the earth once every 100 minutes in a near polar orbit at an altitude of 780km On the surface the system comprises system control segment and telephony gateways connected to the telephone system on earth The uplink to the satellites uses TDMA and FDMA multiplexing methods TDMA reads Time Division Multiple Access which is a technology for delivering digital wireless service using time division multiplexing TDM The radio frequency is divided into time slots which are then allocated to multiple calls so a single frequency is able to carry multiple simultaneous data channels FDMA on the other hand means Frequency Division Multiple Access 5 1 IRIDIUM Communication 70 124 Channels x 8 Time Siote 992 Duplex Channels Figure 5 2 FDMA versus TDMA In case of IRIDIUM the frequency band is 1616 1626 5MHz and is divided int
10. g cgocgccocccgcgcgcosscosgscsg S cocgcgoccgcgcoccogocgcssoscosgocg 0 066 0 047 0 034 0 079 0 054 0 028 0 091 0 073 0 050 0 029 0 090 0 071 0 045 0 024 0 082 0 079 0 112 0 085 0 062 0 044 0 022 0 085 0 064 0 038 0 013 0 086 0 062 0 038 0 018 0 089 0 072 0 047 0 029 0 085 0 063 0 039 0 015 0 085 0 073 gm occcocccocccccocccoccccccsc mc OocgcoOoGcocccccoccoccccocccccc 2733 307 7 352 7 214 6 225 4 240 5 211 4 214 8 215 9 219 3 212 2 216 9 221 0 226 5 195 5 165 6 152 6 313 5 318 0 319 5 322 9 310 5 314 2 320 8 335 8 312 2 319 2 334 3 18 1 308 2 311 6 311 5 325 0 313 9 322 5 335 2 270 0 298 3 283 7 Ooocococcocoooccoocoocooc OGcococococcocoocooccococooocoog 0 018 0 016 0 014 0 014 0 016 0 017 0 016 0 014 0 016 0 016 0 016 0 016 0 016 0 016 0 016 0 025 0 016 0 017 0 013 0 013 0 015 0 016 0 016 0 018 0 016 0 015 0 017 0 017 0 015 0 017 0 016 0 016 0 017 0 014 0 016 0 016 0 014 0 015 0 014 cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb 287 9 304 7 298 0 298 0 306 6 297 4 294 0 296 3 311 9 293 0 291 5 289 0 289 0 304 6 320 5 347 2 350 7 a z squiod jueuno x q L squiod jusuuno v G sjulod Bulseq m q SU Od BM 2 z smod uano x e L sjuod jueuno P sjuiod Buiseq e s
11. ifdef SPI SER B undef SPI SER B define SPI SER D endif ifndef SPI SER D define SPI SER D endif ifdef SPI SER D duse SPI lib endif EndHeader char display1 128 char display2 128 char display3 128 char display4 128 f START FUNCTION DESCRIPTION KKEKKKKKKKKKKKKKKKKKKK I x AA ko ko ko UpdateMotorOutput drive lib D 2 drive lib SYNTAX void UpdateMotorOutput DESCRIPTION PARAMETER RETURN VALUE Lu aN EY WORDS END DESCRIPTION OKCKCKCKCkCkCk ck kCk Ck kCk Ck k ck k kc k ck kc I OK ke e x kx void UpdateMotorOutput SPIinit SendToDAC SwapBytes int zero_output long max output motor speed SendToDAC SwapBytes int zero_output long max output motor speed SendToDAC SwapBytes int zero_output long max output motor speed SendToDAC SwapBytes int zero_output long max output motor speed printf motorspeeds A B C D are d d d dWn motor_speed 0 motor_speed 2 C0 a GA aag 181 0 100 DACA 1 100 DACB 2 100 DACC 3 100 DACD motor_speed motor speed U UT TT BeginHeader forward full void forward full EndHeader START FUNCTION DESCRIPTION CC C Ck C Ck C CK CI CI CI I I C C x Kk Kk Kk AA AA void forward full lt drive lib gt SYNTAX void forward_full U ESCRIPTION che
12. const char READ_AIN11 WRITE POWER IN11 XREF2 const char READ AIN12 WRITE POWER IN12 XREF2 const char READ AIN13 WRITE POWER IN13 XREF2 const char READ AIN14 WRITE POWER IN14 XREF2 const char READ_AIN15 WRITE POWER IN15 XREF2 EndHeader START FUNCTION DESCRIPTION KKEKKKKKKKKKKKKKKKKKKKKKK KG KG ko ko ko float ReadAD char Command int Samples lt analogin lib gt SYNTAX float ReadAD char Command int Samples DESCRIPTION will command the A D to take a reading on the selected channel It will take the average of the Specified number of readings and convert the value to volts using the predefined scale factor PARAMETER address of command bytes must be 3 bytes PARAMETER2 int number of readings to average RETURN VALUE float volts needs to be scaled by scale factor KEY WORDS END DESCRIPTION OKCKCKCKCkCkCk ck kCk Ck kCk Ck k ck k kc k k kc k Ck k ck kck ck ckck ck kok kok ke ke e x kx float ReadAD char Command int Samples int Count data_one int data_one_comp twos complement if needed char data 2 conversion result as a 16 bit 2 long data all all data samples added float Voltage return value SPI Binit BitWrPortI PDDR amp PDDRShadow 1 0 PDO 1 BitWrPortI PDDDR amp PDDDRShadow 1 0 PDO output data all OL reset data all D 1 analogin lib 16
13. IS THAYER NS SCHOOL OF NGINEERING M Q U T H C Lo L E GE Communication Navigation and Control of an Autonomous Mobile Robot for Arctic and Antarctic Science Diploma Thesis by Goetz Dietrich and Toni Zettl Start date 10 01 2004 End date 04 01 2005 Supervisor Prof Laura Ray Supervising Professor Prof Dr Ing K Landes Abstract This Thesis describes two different main fields of work on the Cool Robot Cool Robot is a low budget autonomous mobile robot The mechanical design and layout was made as an earlier part of a Diploma Thesis Most of the mechanical parts were already produced This thesis describes the assembly process for the Cool Robot What has to be done and which is the correct sequence are questions that are answered in the Thesis However the main parts of this Thesis deal with the overall navigation algorithm the control and the communication and data storage On the navigation side the realization of an open loop course correction is evaluated and shown The goal is an autonomous waypoint following path with a top speed of over m s The navigation is therefor entirely based on GPS data The robot s main control is done with a 8 bit microcontoller which controls the brushless DC motors in velocity mode The communication part deals with the connection between the robot and a laptop or desktop PC through a handheld radio with radio modem The communication protocol will be the focus here T
14. Software frame work The basic idea of CoolRobots Software is one superior main routine with a start up section which is executed only once when the program is started and a big infinite loop that executes all subordinated functions and algorithms according to the present demands pictured by the sensors Sensor input FT Figure 7 1 Rough schematic of CoolRobots software What exactly is executed on every run through the loop depends on certain global variables which can be changed by the functions that compute input data Thus on every cycle off the 7 1 Definitions libraries and variable declarations 116 main loop the parameters are set for the next cycle As shown in figure 7 1 the main program constist four major parts 1 The startup routine 2 a block for the modem input 3 the main control section 4 and a block for the modem output The modem input output blocks and the main controll section form the main loop of Cool Robots control program The reason they are listed separately is they are separated within the code too They are all placed within their own Costate which allows those three tasks to run seemingly parallel DynamicC is capable of some kind of multithreading which they call cooperative multi tasking Cooperative multitasking is a way to perform several different tasks at virtu ally the same time An example would be to step a machine through a sequence of tasks and at the same ti
15. The program continuously queries if one of the keys w a s d or q is pressed and converts the input into commands to the motor controllers The speed for all four wheels will always be between 100 and 100 and the speeds of front and rear wheels of one side will always be equal w increase speed by 10 of full speed S decrease speed by 10 of full speed a turn to the left decrease speed of the left wheels by 10 and increase speed of the right wheels by 1096 d turn to the right increase speed of the left wheels by 1096 and decrease speed of the right wheels by 10096 q Stop put the wheel speeds to 0 in 10 steps every 100ms p switch to waypoint following at full speed short cut for command CRCMDMANDM see table 5 15 Table 5 13 Control keys for manual driving Within the next logical step this principle was adapted to wireless solution as soon as the radio link was available Since it is very inefficient and slow to send every typed character on its own a arbitrary long series of characters can be typed an sent to the robot by pressing carriage return CR The string will be computed character by character and the motor speeds are 5 3 Controling the CoolRobot via radio link 96 updated after every valid controll character If some character other than w a s d or q is typed it is simply ignored For example if the robot is standing with all motor speeds set to zero percent the string Wwwwaa will force it t
16. U TL TT BeginHeader backwards tilt void backwards tilt EndHeader START FUNCTION DESCRIPTION ACkCkCk ck ck ck ck kck ck k ck ck k ck ck ck k ck k kk k kk kk D 2 drive lib 183 void backwards_tilt lt drive lib gt SYNTAX void backwards_tilt O ESCRIPTION backs up Cool Robot in case of high tilt sensors PARAMETERI RETURN VALUE Gl nN EY WORDS END DESCRIPTION OKCKCKCKCkCkCk A I k kck ck kok ck kok kok kk ke e x kx void backwards tilt while motor_speed 0 100 amp amp motor_speed 3 100 costate slower forwards motor speed motor speed increment waitfor DelayMs 200 end costate end while end function ULL TT BeginHeader manual drive int manual drive char drive string extern int drive mode EndHeader const char cmp_drive wasdqp START FUNCTION DESCRIPTION Ck CK CK CK Ck Ck Ck CK CK CI CI CIC CK CC CC CK CK AA AA A AZ A Ck A k Kk Kk Ax kx Ax x manual drive drive lib SYNTAX aN EYWORDS O ESCRIPTION PARAMETERI PARAMETER2 RETURN VALUE Gl SEE ALSO END DESCRIPTION OKCKCKCKCKCkCk Ck kCk Ck kCKCkCkCK Ck kCK Ck kCKCkCkCKCKCkCKCkCkCK Ck kCk Ck k Ck k kc K kk k kk I kk I ke ke int manual drive char drive string D 2 drive lib 184 int c c
17. c c sen for k 2 6 count a count d count s count w x ount a 0 ount d 0 ount s 0 ount w 0 0 d event 6 x 0 x lt strlen drive_string x if drive_string x cmp drive 0 faster forwards motor speed motor speed else if drive string x cmp drive 1 turn_left motor_speed angle else if drive_string x cmp drive 2 slower_forwards motor_speed motor_speed_ else if drive_string x cmp_drive 3 turn_right motor_speed angle else if drive_string x cmp_drive 4 stop motor speed motor speed increment else if drive string x cmp drive 5 drive mode wp start 0 end elseif end for nd manual drive 1 w accelerate robot increment a take a left turn slow down robot ton increment d take a right turn gq stop robot p exit manual drive mode U UT CL GE TT B eginHeader wp follow full int wp follow full extern extern extern extern extern extern extern E I GPSPos ar in stri 128 tm hc wheel air wp start GPS inv limit tm nav PSPosition curr p2 Header c n n n n n n DE n koz as i i i G nd ition curr p2 START FUNCTION DESCRIPTION int wp follow full SYNTAX lt drive KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK
18. dpFloat2D n lon d lon lon dif gt lon diflim abs c lt 0 Calculation of bearing ouble lat_c oat2Double oat2Double lat y dpFl lon x dpF lat d lon cG lon y dpFloat2Double lon Q3 dista dummy 00 bearing dummy 01 dpFloat2D acos dummy01 bearing end if dpDoubl else ouble dist dpDiv dpSub dpSine lat y dpMul dpSine lat x dpCosine dista dpMu dummy01 dpAdd dpArctan dpDiv dpNeg dummy00 dpSqrt dpAdd dpMul dpNeg dummy00 dummy00 dpMakeNum 0x3 00000 0x0 1 dpMul dpV dpAtan dummy00 dpSgrt dummy00 dummy00 1 2 dpAtan 1 e2Float dummy01 D 3 gps lib 198 lat x dpFloat2Double lat_c lat y dpFloat2Double lat d lon x dpFloat2Double lon c lon y dpFloat2Double lon d dista dpFloat2Double dist dummy00 dpDiv dpSub dpSine lat y dpMul dpSine lat x dpCosine dista dpMu bearing 2 PI acos sin lat d sin lat c cos dist sin dist cos lat c dummy01 dpAdd dpArctan dpDiv dpNeg dummy00 dpSqrt dpAdd dpMul dpNeg dummy00 dummy00 dpMakeNum 0x3 00000 0x0 1 dpMul dp dummy01 dpAtan dummy00 dpSqrt dummy00 dummy00 1 2 dpAtan 1 bearing dpDouble2Float dummy01 bearing 2 PI bearing end else end else return bearing 180 PI BeginHeader gps_basing_point gps_basi
19. wp 1 bearing to bp start pom distance to bp Figure 3 2 Visualization of most important terms for GPS navigation The main principle of the navigation is waypoint following see chapter3 2 Cool Robot re ceives GPS data which includes latitude and longitude for the current position The user provides a list of waypoints he wants the robot to reach By calculating its current position the robot then travels on a predetermined path to the next waypoint When within a certain range of that waypoint the path to the next waypoint will be calculated For two waypoints being away from each other over 10 km the robot generates basing points see chapter 3 2 on the track in a distance of 1 km to each other 3 1 GPS Navigation 17 3 1 GPS Navigation Everybody has heard about Global Positioning System but how exactly can a robot travel in Antarctica only relying on the GPS Signal The NAVigation Satellite Timing and Ranging NAVSTAR Global Positioning System is an all weather radio based satellite navigation system that enables users to accurately deter mine 3 dimensional position velocity and time worldwide The GPS System was originally invented for the military and is run by the American Department of Defense The System con sists of 24 satellites operating in 12 hour orbits in an altitude of 20 200 km around the Earth that emit signals which can be received on Earth by GPS receivers The constellation is divided in six orbi
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21. 33sec 35475sec 519 25min 9 85h Thus we are able to record nearly ten hours of continuous waypoint following in detail This time grows even bigger considering the original GPS string as well as some other recorded values are not essential for later analysis Just cutting down on the original GPS string saves us 52Bytes which drops the size of one data set to only 185Bytes Doing the math again we should be able to store just around 1365 data sets equivalent to 1365 33sec 45045sec 750 75min 12 51h A gain of more than 2 5 hours This time can be grown easily by cutting some data that is not quiet essential for the analysis of the the robot s behavior For the tests in Greenland the datalogger might be available to store all this data but just in case it is not ready the flash file system might be a sufficient way to collect data from test runs of nearly one day Or it can be used as a spare system Assuming that the navigation is working fine there might be no need to record all the navigation data or even no navigation data at all Besides there is always the possibility to send this data to the base station or operator and record it locally on the PC for later analysis This would allow for the storage of all interesting sensor data in the flash file system clearly arranged in different files for each kind of data The data we are recording is basically the same as which is sent back via the radio connection when CoolRobo
22. 4337 6696 4337 6594 4337 6499 4337 641 4337 628 43371 6572 43317 6179 43317 6228 4337 634 43317 6462 4337 6513 43317 6594 43371 6643 4337 6696 43317 6756 4337 682 4337 6901 ZZZZZZZZZZZ Z ZZZZ ZZ ZZ ZZ Z ZZ Z ZZ ZZ ZZZZZZZZZZZ Z ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ Z ZZZZZZZZZZZZZZZ 7209 217 7209 268 7209 261 7209 251 7209 239 7209 225 7209 218 7209 206 7209 194 7209 188 7209 179 7209 168 7209 16 7209 147 7209 131 7209 051 7209 105 7209 088 7209 076 7209 066 7209 054 7209 044 7209 03 7209 015 7209 005 7208 996 7208 982 7208 973 7208 959 7208 949 7208 938 7208 924 7208 912 7208 902 7208 887 7208 874 7208 861 7208 852 7208 842 7208 832 7208 819 7208 809 7208 8 7208 785 7208 771 7208 804 7208 758 7208 755 7208 745 7208 76 7208 784 7208 809 7208 832 7208 841 7208 844 7208 848 7208 851 7208 855 7208 865 7208 875 7208 88 7208 887 7208 896 7208 902 7208 907 7208 911 7208 918 7208 927 7208 938 7208 944 7208 952 7208 961 7208 969 7208 977 7208 985 7209 053 7209 01 7209 031 7209 046 7209 056 7209 065 7209 079 7209 098 7209 112 7209 128 7209 144 7209 159 Z 25 2 A S 4 S 4 4 4 4 4 Z S S 4 S 4 4 4 4 S 4 4 4 4 4 S 4 4 4 4 S 4 4 4 4 4 Z S S 4 S 4 4 4 4 S 4 4 4 4 4 S 4 A 4 4 S 4 4 4 4 4 Z S 8 8 S 4 4 4 4 4 4 0 284 0 269 0 244 0 224 0 199 0
23. 4338 07 338 07 338 065 338 060 338 055 338 049 338 044 338 037 338 032 338 026 4338 0 338 013 338 007 338 002 337 996 2 66 R 30 n o vq 0 R 06 ERU OUJ VU 4 7 4 9 337 9909 4337 98 4 337 9762 337 9691 337 963 337 958 337 952 337 947 1 4 9 4 N N N N N N N N N N N N N 7209 3244 7209 12 7209 3139 7209 3019 7209 2925 7209 2842 7209 2738 7209 2632 7209 2506 7209 2373 7209 2239 7209 2123 7209 2033 7209 1921 7209 1811 7209 1733 7209 1638 7209 1541 7209 1457 7209 1375 7209 1302 7209 1208 7208 76 7209 0889 7209 0736 7209 0612 7209 0505 7209 0401 7209 0296 7209 0199 7209 0099 7209 0011 7208 9875 7208 978 7208 9625 7208 949 7208 939 7208 9282 7208 9182 7208 9079 7208 8985 7208 8908 7208 8743 7208 8615 7208 8471 7208 8368 7208 8258 7208 8139 bp cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 bp cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 4338 0999 4337 8985 4337 9078 4337 9144 4337 9252 4337 9353 4337 9425 4337 952 4337 9613 4337 9695 4337 980 4337 9888 4338 0002 4338 0133 4338 0235 4338 0344 4338 0437 4338 0533 4338 0627 4338 0727 4338 0838 4337 91267 4338 0957 4338 0899 4338 0835 4338 077 433
24. 7208 895 7208 9 7208 905 7208 909 7208 916 7208 924 7208 935 7208 94 7208 95 7208 959 7208 967 7208 976 7208 981 7208 992 7209 3 7209 022 7209 04 7209 051 7209 065 7209 073 7209 091 7209 108 7209 123 7209 139 7209 153 7209 167 bp cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 bp cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 bp cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 bp cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 4338 0235 4337 9779 4337 9849 4337 9952 4338 0028 4338 0118 4338 0182 4338 026 4338 0367 4338 05 4338 0592 4338 0672 4338 0769 4338 0845 4338 0912 4338 0614 4338 0992 4338 0925 4338 0844 4338 0762 4338 0684 4338 0636 4338 0584 4338 051 4338 0453 4338 04 4338 034 4338 029 4338 0235 4338 0177 4338 0125 4338 0066 4337 9984 4337 9937 4337 9875 4337 981 4337 9739 4337 9687 4337 964 4337 9591 4337 9535 4337 9482 4337 9437 4337 9379 4337 9299 4337 8738 43317 9124 4337 8969 4337 8763 4337 8576 4337 8527 4337 8599 4337 8681 4337 8576 4337 8456 4337 8372 4337 8247 4337 8126 4337 7998 4337 7909 4337 7785 4337 7663 4337 7578 4337 7484 4337 7373 4337 7253 4337 714 4337 704 4337 694 4337 6793
25. 7208 969 7208 957 7208 947 7208 937 7208 923 7208 914 7208 903 7208 893 7208 88 7208 866 7208 85 7208 835 7208 823 7208 812 7208 799 7208 784 7208 773 7208 806 7208 759 7208 764 7208 714 7208 787 7208 791 7208 798 7208 803 7208 809 7208 816 7208 823 7208 83 7208 837 7208 833 Z S 8 A S 4 4 S 4 4 4 4 4 4 Z S 4 S S 4 A4 4 4 4 4 4 4 4 S 4 4 4 4 4 4 4 4 4 4 4 4 4 Z S S 4 4 4 S 4 4 4 4 S 4 4 4 4 S 4 A 4 4 4 S 4 4 4 4 4 4 Z S 8 S 4 S 4 4 4 4 S 4 4 0 242 0 223 0 198 0 175 0 156 0 140 0 118 0 097 0 075 0 051 0 062 0 080 0 049 0 031 0 586 0 563 0 533 0 509 0 486 0 457 0 44 0 4 0 39 0 36 o Uo a o W V 0 30 PP we RAaR R oameod 0 26 0 577 0 561 0 54 0 52 o tA e 0 48 0 44 0 40 o T a o T N Qo oo RREROUOIoOoRUO 0 36 SE E S E 42224222228 S S K S E K 4 S A S K 4 S K S K S S 4 S K 4 44 4 S E 4 E S E E KS K S E AS K S E AS K S K AS A S K 4 S 4 228 s 8 E E S E 4 2222428 318 5 320 7 322 2 323 1 325 9 330 9 336 5 340 9 347 5 270 0 27 6 513 67 1 LS 31 9 34 7 32 9 31 7 30 0 29 7 29 3 30 1 30 3 30 2 31 1 31 6 31 8 32 0 32 7 33 0 323 33 6 35 0 38 9 39 9 40 8 43 2 47 6 53 2 61 5 74 5 91 9 26 6 25 1 25 0 24 8 24 9 24 9 24 4 24 0 24 6 25 2 255 25 9 26 1 25 9 26 2 26 3 26 4 26 8 26 9 26 3 26 3 26 9 28 1 29
26. C rated Maxim MAX3232I RS232 line driver receiver This 16 pin surface mount IC is good for two serial interfaces in our case serial port E and F For the communica tion between micro controller and radio modem or rather the IRIDIUM modem later on serial port E is reserved and port F will be used to interface with the data logger DOUT1 TXE RS232 BYPASS DOUT2 TXF RS232 aa RIN1 RXE RS232 RIN2 RXF RS232 ROUT1 RXE Jackrabbit PG7 ROUT2 RXF Jackrabbit PG3 DIN1 TXE Jackrabbit PG6 c DIN2 TXF Jackrabbit PG2 VCC 3 3V ROUT1 GND GND ai C1 C2 C3 CA 0 1pF DOUT2 DIN2 ROUT2 Figure 5 11 Pinouts MAX3232 RS232 line driver receiver The RS232 driver receiver is soldered to a small multipurpose board including all necessary capacitors this work was done by Alex Streeter The small board is located on the empty area 5 2 Radio Communication 87 on the RCM3100 evaluation board The two serial interfaces are conducted on a 10 pin IDC connector for ribbon cable Jl oo oo XES pv gt O oOo Figure 5 12 Wiring of the MAX3232 on the RCM3100 evaluation board Another issue is the connection between the KPC3plus and our transceivers One can find a lot of wiring examples within the KPC3plus manual but none for Cobra radios So in the first place we tried to figure out a way ourselves by soldering the wires for PTT Push To Talk RX Receive data TX Transmit data and GND Ground t
27. PI 180 lon b b gt lon degrees b gt lon minutes 60 if b gt lon direction E lon b lon b lon b lon b PI 180 lat x dpFloat2Double lat a lat y dpFloat2Double lat b lon x dpFloat2Double lon a lon y dpFloat2Double lon b dummy00 dpAdd dpMul dpSine lat x dpSine lat y dpMul dpMul dpCosine lat x dpCos dummy00 dpSin lat a dpSin lat b dpCos lat a dpCos lat b dpCos lon a 1 diss dpAdd dpArctan dpDiv dpNeg dummy00 dpSart dpAdd dpMul dpNeg dummy00 dummy00 dpMakeNum 0x3 00000 0x0 1 dpMul dpV angle dpAtan dummy00 dpSqrt dummy00 dummy00 1 2 dpAtan 1 diss dpMul diss dpMakeNum 0x40584d200 0x0 6354 angle angle 6354 angle dpDouble2Float diss BeginHeader gps bearing float gps bearing GPSPosition c GPSPosition d float dist EndHeader START FUNCTION DESCRIPTION ACkCkCk ck kCk ck kCck ck ck ck ck k ck ck k X k ck k ck ck k ck ck k ck ck ck k ck ck kk ck k k kk kk gps bearing gps lib SYNTAX float gps bearing GPSPosition a GPSPosition b dist A EYWORDS gps O ESCRIPTION Calculates bearing in degree from one geographical point a to a geographical point b Uses spherical earth model PARAMETER1 a first point PARAMETER2 b second point PARAMETER3 dist ground distance between the two points a b
28. Screen shot of Short Cut third step select tables 111 Rough schematic of CoolRobots software 115 Flow chart of mainprogV0 34 2 2 0 lee 131 Flow chart of mainprogV0 35 lt lt lt lt 2 eee 133 Cool Robot navigating to a waypoint on lake mascoma 136 Navigation routine at startup lt lt lt eA 139 Waypoint and basing point shifting sample lt lt lt 140 Off bearing with basing points every 100m 141 Off bearing with basing points every 500m 141 Current draw data on SNOW oua soe BS se Etre obe Mee Sad RC 8 a 143 Screen shot of mapquest com showing the starting point and the point the last transmission was received before losing connection 147 Waypoint following with basing points every 1OOm 160 Waypoint following test with basingpoints on waypoints 161 2nd order Butterworth Filter for the 2 axis tilt sensor 163 Conditioning circuit for the analog motor velocitiy and motor current inputs 164 Schematic of DAC connections lt lt lt s lt s s 000 ee eee 165 LIST OF TABLES Vili List of Tables 1 1 3 1 3 2 3 3 3 4 3 5 3 6 3 7 3 8 3 9 4 1 4 2 5 1 5 2 5 3 5 4 5 5 5 6 5 7 5 8 5 9 5 10 5 11 5 12 5 13 Main topics of work on Cool Robot lt lt lt lt lt 44 lt lt lt 3 NMEA 0183 Specification Revision 2 0 1
29. The TLV5614 has 4 DAC s with a resolution of 12 bit and an output voltage A 12 bit resolution says that a voltage range here 4 2 12 bit Voltage output DAC with serial interface 54 the output voltage is divided into 2 4096 steps The smallest part each voltage step differs from the next is the LSB Least Significant Bit xs voltagerange Supply voltage for the part is 5V VREF is set to 10 V The DAC is connected to serial port D on the Jackrabbit main controller for connections refer to Table 3 6 The four DAC s are easily accessable through a 3 wire serial inter face SPI using the provided code for the SPI lib Fisur d d Spi interiace If there is only one device connected to the serial port CS can be tied low The maximum serial clock frequency for the TLV5614 is 20 MHz The FS pin is the Frame sync input pin A falling edge has to be generated on this pin to shift the data in the serial output to the DAC where the minimum high level digital input voltage for DVpp 5V is 2 2 V and the maximum low level is 0 9 V The falling edge on FS starts shifting the 16 bit data word with the MSB Most Significant Bit first to the internal register of the DAC clocked by the 16 falling edges of the serial clock After FS rises or the sixteen bits have been shifted the addressed DAC updates the output The data consists of four control or address bits followed by the 12 bit DAC value DACA which is addressed by 0000
30. longer drive string rather then sending character by character In order to find out what the maximum range of operation is like we started the robot navigating to a waypoint 3km down the lake and watched the incoming navigation data until the connection was lost and no more data was received Taking the last GPS position received from the robot and the GPS position of the car see Figure 8 7 where the robot started we calculated a distance of slightly above 1200 meters Nearly four times the range achieved with the Cobra radios 8 4 Radio Interface and Communication 147 sfLLLLLLLLELB Figure 8 7 Screen shot of mapquest com showing the starting point and the point the last transmission was received before losing connection We were running several tests with the navigation algorithm on Mascoma Lake always get ting all navigation data send back from the robot and never encountered a problem with the communication system In the first tests we were driving behind the robot within a range of 200m to 300m to be sure no data is lost or the connection is interrupted In the latest tests on a fairly cloudy day the robot was doing a rectangle shaped route with round about 600m to each side see figure B 2 and the car with the receiving modem remained on the corner the robot started instead of driving relatively near to the robot Thus the maximum distance was around 850m between robot and car and absolutely no problems occurred I was watc
31. return 5 else if strnemp chk string SCRSRQ 6 0 case4 status request send_event 3 send back a status report return 6 else if strncemp chk_string SCRDRQ 6 0 case5 data request send_event 4 send back last mins of data stored return 7 end elseif else case6 undefined unimportend string received return 8 end if end processModemStr BIBLIOGRAPHY 216 Bibliography 1 A S Laura Ray Alexander Price and D Denton The Design of a Mobile Robot for Instrument Network Deployment in Antarctica paper ICRA 2005 2 D S A et al Nomad 2004 3 NASA JPL 2004 4 G Gravenkoetter and G Hamann Development for a Cool Robot for the Antarctic Diploma Thesis Thayer School of Engineering 2004 5 A Price CoolRobot Mechanical Design of a Solar Powered Antarctic Robot Honor s Thesis Thayer School of Engineering 2004
32. 0 015 0 016 0 015 0 016 0 015 0 016 0 016 0 016 0 017 0 016 0 014 0 016 0 014 0 017 0 016 0 017 0 016 0 016 0 015 0 018 0 017 0 017 0 015 0 016 0 018 0 017 0 017 0 016 0 015 0 017 0 015 0 016 0 016 0 015 0 016 0 016 0 017 0 016 0 017 0 017 0 015 0 015 0 018 0 016 0 016 0 016 0 016 0 015 0 015 0 015 0 015 0 016 0 014 0 016 0 013 0 017 0 016 0 015 0 017 0 015 0 016 0 017 0 017 0 016 0 014 0 015 0 015 0 016 0 016 0 014 0 017 0 016 0 016 0 015 0 014 0 016 cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb 35 9 28 0 49 2 55 4 39 1 48 7 49 2 2 8 34 3 46 0 32 8 48 1 62 0 44 0 270 0 140 8 195 4 243 7 275 6 324 210 188 199 9 188 192 6 200 9 228 188 5 197 2222 207 196 2 189 8 206 8 209 4 225 9 187 5 210 8 209 4 211 4 220 4 200 0 217 6 284 9 307 0 343 9 304 6 320 4 285 4 302 3 295 5 299 9 302 1 316 0 158 cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl aw aw cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl aw cpl cp
33. 00 A 4342 5581 N 07216 9284 W 0 0 270 0 190105 2B SGPRMC 152559 00 A 4342 5581 N 07216 9284 W 0 0 252 8 190105 22 SGPRMC 152600 00 A 4342 5581 N 07216 9283 W 0 0 214 9 190105 29 SGPRMC 152601 00 A 4342 5576 N 07216 9282 W 0 8 176 0 190105 27 SGPRMC 152602 00 A 4342 5572 N 07216 9281 W 1 3 169 5 190105 22 SGPRMC 152603 00 A 4342 5565 N 07216 9278 W 1 9 168 6 190105 2B SGPRMC 152604 00 A 4342 5558 N 07216 9275 W 2 2 165 7 190105 2B SGPRMC 152605 00 4 4342 5551 N 07216 9275 W 2 2 173 6 190105 25 SGPRMC 152606 00 A 4342 5544 N 07216 9275 W 2 3 180 8 190105 21 SGPRMC 152607 00 4 4342 5538 N 07216 9275 W 2 2 182 0 190105 20 SGPRMC 152608 00 A 4342 5531 N 07216 9276 W 2 3 188 0 190105 2E Figure 3 5 WinOncore for Motorola M12 GPS receiver with GPS data in NMEA for mat The software compiles the Motorola Binary I O commands to initialize or configure the GPS receiver Once in NMEA format the user can decide between following different NMEA out put messages Message Description GPGGA GPS Fix Data GPGLL Geographic Position Latitude Longitude GPGSA GPS DOP and Active Satellites GPGSV_ GPS Satellites in View GPRMC Recommended Minimum Specific GPS Transit Data GPVTG Track Made Good and Ground Speed GPZDA Time and Date Table 3 1 NMEA 0183 Specification Revision 2 0 1 The easiest way to change the receiver s output is with the software Otherwise see Motorola 3 1 GPS Navigation 21 M12 GPS receiver
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35. 3 1 1 The Motorola Oncore M12 GPS receiver 19 3 22 Main program for autonomous navigation lt 23 3 2 1 Calculating the distance between two gps positions 30 3 2 2 Calculation of gps bearing and off bearing 33 3 2 3 Double precision floating point in dynamic C 34 2 9 Analog SeNnsODS sor oce ae k RU by dann BR dok Ae dd kok dvd 37 3 3 1 Power and signal supplies and setup for the ADC evaluation board 37 3 3 2 12 bit 16 channel Analog to Digital Converter on serial portB 39 3 3 3 Dual axis accelerometer used as atiltsensor 44 3 3 4 Motor current and motor velocity sensors 46 3 3 5 Function to process the sensor data 47 3 3 6 Sensor interrupts ce x dj 6 Se Be ae Bi eda Eu 48 4 The overall control unit 51 4 1 Navigation and control mode overview lt llle 52 4 2 12 bit Voltage output DAC with serial interface lt lt lt 53 4 3 AMC brushless servo amplifier and EAD brushless dc motors 55 4 4 The different drive modes of Cool Robot lt lt lt lt 57 4 4 1 Waypoint following at full speed o aa 59 4 4 2 Waypoint following at partial speed 61 4 4 3 Manual Operator dou e 62 4 5 Perspective on further drive modes ooa 00000 64 4 5 Charge cycle umia RR Rb he ea 64 4 5 2 Stationary dataaquisition lt lt 2
36. 5 214 0 221 8 236 4 212 5 214 8 215 4 212 208 7 215 9 231 9 ococcooccococo OGcOcGcOoOGcOoGcococococoocococooocococoooc OGcOoccOoGcOoGcoccococoocooccocoooccocoooo oococcocoocooocoog 0 016 0 016 0 015 0 017 0 016 0 016 0 015 0 015 0 017 0 017 0 017 0 015 0 015 0 015 0 017 0 014 0 015 0 015 0 019 0 017 0 017 0 016 0 016 0 016 0 016 0 014 0 017 0 016 0 017 0 014 0 016 0 017 0 016 0 020 0 015 0 017 0 017 0 018 0 017 0 015 0 016 0 013 0 015 0 016 0 017 0 015 0 015 0 017 0 016 0 016 0 017 0 017 0 016 0 016 0 016 0 016 0 015 0 016 0 016 0 016 0 014 0 016 0 016 0 016 0 016 0 015 0 016 0 016 0 017 0 014 0 015 0 016 0 014 0 016 0 017 0 016 0 016 0 020 0 017 0 016 0 015 0 016 0 017 0 014 0 014 0 014 cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb cb 298 0 293 0 314 0 313 2 298 0 295 6 307 0 319 0 319 6 328 6 243 8 290 4 55 3 55 4 270 0 90 0 66 6 26 8 2 3 32 8 2 2 23 31 4 28 0 8 9 23 0 42 9 0 24 7 356 9 48 0 30 0 23 4 74 23 4 22 1 24 6 30 1 92 8 191 9 194 6 233 2 191 9 199 1 206 9 199 9 205 7 214 3 2
37. 7209 302 7209 29 7209 282 7209 276 7209 269 7209 263 7209 26 7209 253 7209 245 7209 239 7209 234 7209 228 7209 218 7209 212 7209 207 7209 207 7209 196 7209 186 7209 181 7209 177 7209 172 7209 167 7209 161 7209 155 7209 131 7208 76 7209 113 7209 105 7209 095 7209 082 7209 07 7209 063 7209 05 7209 035 7209 02 7209 004 7208 994 7208 98 7208 969 7208 959 7208 947 7208 937 7208 926 7208 914 7208 907 7208 893 7208 883 7208 869 7208 856 7208 84 7208 827 7208 812 7208 802 7208 789 7208 776 7208 765 7209 7208 761 7208 768 7208 783 7208 789 7208 795 7208 803 7208 807 7208 813 7208 823 7208 828 7208 836 7208 839 7208 823 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 bp cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 bp cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 bp cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 4337 6984 43317 7033 4337 7101 4337 7186 4337 7264 4337 7311 4337 7367 4337 7449 4337 7539 4337 1655 4337 7753 4337 770 4337 7852 4337 792 4337 876 4337 876 4337 8246 4337 842 4337 8577 4337 8603 4337 8678 4337 8774 4337 8853 4337 8964 4337
38. 8 30 5 29 6 31 6 34 7 38 9 43 4 52 9 21 212 21 212 212 213 213 214 214 214 214 6 216 2 220 4 ANEUWUSwWOW sss sosScccccccccccococcccccocccccccc sosSccccoccccccccccccccccccccccc Soc SSS SSS CSS T 0 085 0 065 0 040 0 017 0 085 0 065 0 041 0 019 0 083 0 059 0 037 0 027 0 104 0 114 0 124 0 114 0 079 0 053 0 026 0 087 0 071 0 048 0 026 0 099 0 080 0 057 0 036 0 019 0 099 0 080 0 059 0 035 0 016 0 099 0 073 0 048 0 032 0 097 0 078 0 059 0 041 0 022 0 096 0 090 0 073 0 059 0 038 0 017 0 101 0 079 0 058 0 038 0 013 0 100 0 080 0 060 0 045 0 025 0 099 0 083 0 064 0 048 0 027 0 099 0 081 0 061 0 036 0 012 0 090 0 076 0 055 0 032 0 094 0 079 0 057 0 030 0 082 0 056 0 033 0 092 0 071 0 049 0 033 0 089 0 069 0 070 gmcococccocccccgcccszc gm OCOOCOGCcOcccccoccccccoccccoeccocsszc gm OocOcCOoccccccocccccccoccccccoccccczsc SOS S G G GG G0 G 00505 310 1 315 1 319 0 324 1 310 1 316 3 324 1 332 2 305 5 296 1 322 1 23 7 290 0 281 9 479 64 8 64 9 69 8 74 9 24 4 20 7 23 0 19 9 25 5 28 8 31 0 31 6 34 5 29 2 29 5 25 1 27 9 39 2 33 6 33 8 332 383 282 29 6 324 384 474 124 26 6 26 1 24 7 26 5 28 9 21 1 17 9 20 4 25 6 36 1 26 1 27 3 26 4 28 6 318 25 0 26 4 26 3 23 2 20 6 26 4 29 1 34 1 39 8 48 2 25 4 27 5 29 2 26 9 23 1 228 1 245 5 268
39. 9078 4337 915 4337 9249 4337 9369 4337 9464 43317 9546 4337 962 4337 9727 4337 9819 4337 9917 4338 003 4338 01 4338 029 4338 0369 4338 045 4338 053 4338 0644 4338 0746 4338 0837 4338 0944 4338 1062 4338 070 4338 104 4338 099 4338 0934 4338 0866 4338 0812 4338 0758 4338 0659 4338 0597 4338 0554 4338 0503 4338 0454 4338 0401 4338 0341 4338 0288 4338 0233 4338 018 4338 0133 4338 0082 4338 0033 4337 9948 4337 99 4337 9855 4337 9804 4337 9736 4337 9658 43317 9575 4337 9529 4337 948 4337 9408 4337 9327 4337 8765 4337 9141 4337 8978 4337 8823 4337 8723 4337 8595 4337 8452 4337 8373 4337 8255 4337 8151 4337 8081 4337 7982 4337 7882 4337 7739 ZZZZZZZZZZZZZ Z ZZZ ZZ ZZ ZZ ZZ ZZ ZZ Z ZZ ZZ Z ZZ ZZ ZZ ZZZ Z ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ ZZ ZZZZZZZZZZZZZZ 7209 171 7209 184 7209 201 7209 213 7209 225 7209 239 7209 256 7209 269 7209 281 7209 293 7209311 7209 337 7209 344 7209 332 7209 283 7209 283 7209 343 7209 36 7209 348 7209 329 7209 315 7209 295 7209 29 7209 28 7209 274 7209 269 7209 262 7209 258 7209 252 7209 245 7209 239 7209 233 7209 226 7209 216 7209 211 7209 207 7209 205 7209 192 7209 186 7209 181 7209 176 7209 171 7209 166 7209 159 7209 142 7209 06 7209 124 7209 113 7209 105 7209 092 7209 079 7209 07 7209 059 7209 047 7209 031 7209 014 7209 004 7208 991 7208 978
40. C 2V lt Vow 2V 4 motor current D 2V lt Vow 2V 5 motor velocity A 1 5V Vow lt 1 5V 6 motor velocity B 1 5V Vow lt 1 5V 7 motor velocity C 1 5V Vow lt 1 5V 8 motor velocity D 1 5V Vow 1 5V 9 tilt sensor roll 1 5V Vow lt 3 5V 10 tilt sensor pitch 1 5V Vy lt 3 5V Table 3 5 Analog input channels Most analog to digital converters are not able to handle negative input voltages So we centered 3 3 Analog sensors 38 the output at 2 5V and generated a bipolar input from 0 5V lt Vin lt 4 5V The AD7490 is able to change the input range from 0 to V to 0 to 2 V ef where the reference voltage of Vref 2 5V is provided from an on board high precision reference The only problem was that Analog Devices started the production of their evaluation board in February The power and signal supply for the ADC and the DAC is made through a 20 wire ribbon cable Table 3 6 GND DAC DC DC board 10V DAC DC DC board SDI DAC PCO 5V DAC DC DC board CS DAC PB2 CLKD DAC PFO VREF 45V rabbit eval board 16 GND ADC DC DC board 17 CS ADC PDO 18 CLKB ADC PBO 19 DIN ADC PC4 20 DOUT ADC PC5 NO A U R O NY gt Table 3 6 ADC DAC ribbon cable The on board components of evaluation board include a programmable ultra high precision bandgap reference and four ADG467G guad op amps which are used to buffer the sixteen
41. DelayMs 2000 getgps in stri forward full read sensors costate waitfor DelayMs 1000 sensor range sensor high centered tm hc wheel air costate 1 waitfor DelayMs tm nav 1000 navigate in stri nd stat n end wp fol Figure 4 6 Screen shot of dynamic C code for waypoint following at full speed Figure 4 6 shows a screenshot of the function wp follow full which is written in the drive lib is called directly from the main program Once called it is executed in an endless loop if not interrupted Two kinds of interrupts are build in interrupts driven by the main program e g the interrupt to switch to manual operator drive mode and interrupts driven by the analog sen sors e g a tilt angle higher than 45 degrees For interrupts from main program see chapter 5 3 4 and for interrupts from the analog sensors see chapter 3 3 6 The structure of costate tries to imitate multi tasking The first costate is executed but the stops at the function De layMs which prevents further execution of the costate until the time listed in milli seconds has elapsed If not the second costate is executed and so on Once running the three costates produce a time delay for an execution of the commands listed behind each costate In this case the GPS data string from the Motorola GPS receiver is read the motor speeds are checked if at full speed and the analog inputs are read once every two seconds The interrupts for
42. a call manually requires an extra function or routine that can be omitted using this setting 5 1 IRIDIUM Communication 76 Vn This sets the response format the modem uses either numerical or textual n 0 causes numeri cal responses whereas n 1 causes textual answers For the use with a PC the textual Verbose mode might be the better way whereas for the use with the Jackrabbit numerical answers might be easier to process Zn The Zn command acts as a soft reset and restores one of the two available user defined configurations See description of amp Wn for information on storing user defined configura tions n 0 restore user settings profileO n restore user settings profilel Table 5 3 Modifiers for Zn amp Cn This setting changes the behavior of the modem to the Data Carrier Detect signal DCD which indicates whether the modem is connected to a remote station for data exchange or not n 0 DCD is forced on all the times n 1 DCD indicates the connection status Table 5 4 Modifiers for amp Cn amp Dn This option is used to determine the A3LAs behavior on the Data Terminal Ready DTR signal This signal can be used to end a call The value of n determines the reaction of the modem to a transition of DTR from ON to OFF during a call Valid values for n are 5 1 IRIDIUM Communication 77 0 DTR is ignored the modem changes to in call command mode and if DTR is not restored ON within 10 s
43. and the monitoring of the analog sensors In chapter 4 the control algorithms and the different drive modes are presented Chapter 5 introduces to the communication of CoolRobot An overview of the future IRID IUM communication is given as well as a detailed description of the communication via radio link In chapter 6 a short outline on the data recording capabilities is presented On the on hand using an external datalogger and on the other hand using the storage capabilities of the micro controller The structure and functionality of the CoolRobots software is described in detail in chapter 7 It can also be seen as a basic introduction to the DynamicC programming language with some of its advantages and disadvantages for our application The test results such as current draw and energy consumption waypoint following position data and communcation protocol are presented in chapter 8 Chapter 2 Assembly process for Cool Robot This chapter should give the reader an impression of how extensive even the assembly process for a simple robot is By documenting weak points in the mechanical design and minor or major difficulties during the mechanical work we want to achieve improvements in reliability and performance for the next generation of CoolRobots The outcome should be an update that makes the next generation of CoolRobots better and a choice to beat The combination of the honeycomb chassis and the new generation of solar cell
44. angle lt drive lib gt SYNTAX DESCR PARAM A IPTION ETERI RETURN VALUE Gl EY WORDS END D ESCRIPTION OKCKCKCKCkCkCk ck kCk Ck kCk Ck kc k k kc k k kc k kck ck kok ck ckok kok ko ke ke ke e x kx int turn_right int motor_speed int angle gt 100 amp amp motor speed 1 gt 100 amp amp motor speed 0 angle 100 gt if motor_speed 2 amp amp motor_speed 3 angle 100 motor_speed 0 angle motor_speed 3 angle UpdateMotorOutput end if else if motor_speed 0 lt 100 amp amp motor_speed 3 lt 100 amp amp motor_speed 2 lt 100 angle amp amp motor_speed 1 lt 100 angle motor_speed 2 angle motor speed 1 angle UpdateMotorOutput end if D 2 drive lib 176 else if motor_speed 2 lt 100 angle 2 amp amp motor_speed 1 lt 100 angle 2 amp amp motor_speed 0 gt angle 2 100 amp amp motor_speed 3 gt angle 2 100 motor_speed 2 angle 2 motor speed 1 angle 2 motor_speed 0 angle 2 motor_speed 3 angle 2 UpdateMotorOutput end if return motor_speed end function VITIA L L TL L L T TL L ATT BeginHeader turn left int START FUNCTION DI turn left int motor speed EndHeader int angle
45. autonomous navigation 31 whereas radian is lata aiat degrees Gat minutes 60 180 pi In dynamic C the numbers lat etc are defined as IEEE standard 32 bit floating points Sign Exponent Fraction Bias Single Precision 1 31 8 30 23 23 22 00 Lee Double Precision 1 63 11 62 52 52 51 00 1023 Figure 3 15 Precision for decimal values ii The range for floats is not a problem because the exponent is a signed integer in the range of 126 to 127 But if there are no leading zeros the expansion is rounded off at the 23rd digit after the binary point Which is equivalent to aac or 2 384197 The problem with equation 3 1 is was not that it is false but that it is not precise enough for our navigation algorithm because it tries to compensate for not having double precision floats The fact was that dynamic C does not provide a data structure with double precision like C or C A library with a structure with almost double precision was found see chapter 3 2 3 and I developed the formula for a distance calculation on earth based on spherical coordinates For a correct calculation of a distance between two positions on earth the lat itudes and longitudes need to be con verted into azimuth and pole angle To accomplish a range for the azimuth an gle p of 180 lt v lt 180 and 90 lt lt 90 Figure 3 16 Spherical coordinates 3 2 Main program for aut
46. campus The speed was around 1 mph The gps position data was evaluated and charted with excel It should be used to receive an impression on the GPS s accuracy During the testing 3 1 GPS Navigation 18 five satellites were tracked gt z d oo 100 m 3 262 43426 m X AGEMENT e ae 4342 56 STRASENBURGH NN i Va P 7217 055 7217 005 7216 955 7216 905 Figure 3 3 GPS positioning test on j parking lot at Dartmouth Besides the latitude and longitude position information the NMEA 0183 GPS data string also includes information about speed over ground and current bearing The speed over ground is accurate enough to tell a movement of the robot even at low speeds around 0 5 m s whereas the bearing is of no use for the navigation algorithm The GPS bearing is internally calculated with the two last positions As the distance between two points apart 1 second in time the distance between these points is 1 m assumed 90 of the robot s top speed That makes a precise bearing calculation impossible The result is that the robot will have no usable information about the current heading while making a turn or standing still on one point The conclusion is to have an open loop course correction based on course GPS readings or upgrade the robot if necessary with a triaxial magnetic compass 3 1 GPS Navigation 19 3 1 1 The Motorola Oncore M12 GPS receiver The GPS receiver on the evaluati
47. case the robot wants to take a position in which one edge faces the direction of the wind to provide the smallest working surface One other reason for switching to a different drive mode such as waypoint following at partial speed could be a power limit However the Cool robot starts in drive mode waypoint following at full speed after powering up in manual drive mode waypoint_following_full drive mode 2 no or drive mode 3 Ok from power supply forward full speed sets motor_speed 100 key_input 53 yes manual interrupt Y read sensors motor current motor speed tilt interrupt magnetometer gt sets drive mode Y navigate gps navigation basingpoint calculation waypoint following bearing correction Figure 4 5 Flowchart of drive mode waypoint following at full speed 4 4 The different drive modes of Cool Robot 60 I wanted to keep the structure for the drive modes simple and easy so that the next users are able to add drive modes that have to meet different restrictions using the basic functions The basic functions are summarized in Table A 1 App A Dynamic C Dist 8 01 D DARTMOUTH GOETZ CROBOTSLIBS DRIVE LIB Joke fai Fie Edit Compile Run Inspect Options Window Help Doel amp gana P E x lint wp follow full i int count invalid costate waitfor
48. connected with V 42bis compression enabled on transmit direction Data call connected with V 42bis compression enabled on receive direction Data call connected with V 42bis compression enabled on both transmit and receive direction Table 5 11 Overview of AT command result codes 5 2 Radio Communication 81 5 1 2 Prospect on further use In contrast to the communication via the radio modem see chapter 8 4 where a more or less permanent connection is established before Cool Robot starts a journey here only short time frames are available to exchange data between the robot and an operator or supervising base station For each of those time frames a dial up connection must be started either from the robot or the remote station There should be no problems with an incoming call to the robot since the IRIDIUM modem will be in standby all the time As soon as a call arrives the modem will send a RING signal to the micro controller indicating an incoming call The micro controller will accept the call and receive and compute the incoming data The other way around it is very similar the micro controller passes the command to dial the number of the base station and transmit its data as soon as the connection is established The only issue will be to determine when the robot will create a connection and why Certainly the base needs to know whenever Cool Robot encounters problems on its way or stops for some reason There may also be a nee
49. controls the output voltage for motor A for example see the drive lib header for all address bits De ou o Jo Jon Joo J o o o 9 TI T9 T T2219 T9 X don t care SPD Speed control bit 1 fast mode 0 slow mode PWR Power control bit 1 power down 0 normal operation Figure 4 2 DAC 16 bit data word Each DAC s output voltage then is represented by DAC value Vou 2 Vref i 4096 V 4 1 where V 2 5V in our case and the DAC value the 12 bit data word to be transfered in a range from 0 lt x lt 4095 is The reference voltage can be adjusted from OV lt Vref lt 3 3V 4 3 AMC brushless servo amplifier and EAD brushless dc motors 55 with the potentiometer on the DAC board To buffer the DAC s ouput signals we connected an Opamp LM248 to the output channels The final output voltage range is outlined in Figure 4 3 Analog output V VF digital input code 0 4095 Nri f s Figure 4 3 Voltage output vs digital input 4 3 AMC brushless servo amplifier and EAD brushless dc motors The motor controllers are PWM Pulse Width Modulation servo amplifiers of the model AMC BE15A8 H Supplied with 48V the amplifier can be interfaced with a digital controller or used as a stand alone unit The amplifier is controlled by the quad voltage output DAC from Analog Devices Various switches and potentiometers allow the user to adapt the amplifier to the existin
50. cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl aw cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl 337 9421 337 9367 337 9308 337 9244 4337 62 337 9021 4337 884 337 8718 337 8637 337 8558 337 8484 337 8407 337 8324 337 8243 4337 815 337 8072 337 7998 337 7915 337 7826 337 7717 337 7619 337 7531 337 7458 337 7355 337 7277 337 7189 337 7109 337 6999 337 6893 337 6789 4337 67 337 661 337 6534 337 646 337 6387 337 630 337 8002 337 629 337 6353 4337 64 337 6515 337 6574 337 6632 4337 67 337 6766 337 6825 337 6878 337 6953 337 7009 337 7084 337 7141 337 7222 337 7277 337 7338 337 7408 337 7486 337 7562 337 7639 337 7732 4337 781 ZZ ZZZZZZZZZZZZZZZ zzz z ZZZZZZZZZZZ ZZZZZZZZZZZZZZZZZ ZZ z 7208 8035 7208 7935 7208 7832 7208 7695 7209 7208 7605 7208 7673 7208 7773 7208 7843 7208 7912 7208 798 7208 8042 7208 8108 7208 8173 7208 825 7208 8317 7208 8379 7208 8488 7208 86 7208 8679 7208 8766 7208 8849 7208 8929 7208 9012 7208 9075 7208 9149 7208 922 7208 928 7208 9355 7208 9447 7208 9509 7208 9609 7208 9678 7208 9742 7208 9803 7208 9907 7209 3001 7209 0215 7209 0396 7209 0548 7209 0699 7209 0791 7209 0891 7209 1005 7209 1098 7209 12 7209 1297 7209 1424 7209 1518 7209 1646 7209
51. dod d ded 11 2 6 First moving test of Cool Robot 4 4 12 Sl Wat dnd lon on earth uuu oa da Ask ES Ee k ds 14 3 2 Visualization of most important terms for GPS navigation 16 3 3 GPS positioning test on j parking lot at Dartmouth 18 3 4 Options to initialize the GPS unit to output NMEA data 19 3 5 WinOncore for Motorola M12 GPS receiver with GPS data in NMEA format 20 3 6 GPRMC example message lt lt 21 OU Connecte MIO E 25 as usd 8 78 SE OR A OES RSMAS 22 3 8 Flowchart for basic navigation algorithm a 23 3 9 Basingpoint and waypoint example drawing ss 25 3 10 Startup procedure 1 with Cool Robot pointing north 26 3 11 Startup procedure 1 with Cool Robot pointing south 27 3 12 Startup procedure 2 with Cool Robot pointing south 28 3 13 Example startup navigation drawing 4 20 3 14 Basing point generating example drawing 30 3 15 Precision for decimal values lt lt lt a 31 3 16 Spherical coordinates 12 3 v acte qe ctt at n D m IR i Ge c a 31 LIST OF FIGURES vi 3 17 3 18 3 19 3 20 3 21 3 22 3 23 3 24 4 1 4 2 4 3 4 4 4 5 4 6 4 7 4 8 4 9 5 1 5 2 5 3 5 4 5 5 5 6 5 7 5 8 5 9 5 10 5 11 5 12 5 13 5 14 5 15 5 16 Expression builder for double e 34 Sample SPI communication on serial port B 40 12 bit Co
52. fia eg od n 83 1300 2100Hz Frequency Shift Keying lt a 84 Basic wiring of the KPC3plus radio modem 85 Pinouts MAX3232 RS232 line driver receiver 86 Wiring of the MAX3232 on the RCM3100 evaluation board 87 Wiring suggestion for ICOM radios lt lt lt lt lt 87 AUTOBAUD routine running on Hyperterminal 88 MYCALL command using Hyperterminal 89 ECHO ON OFF command using Hyperterminal 90 LIST OF FIGURES Vii 5 17 5 18 5 19 5 20 5 21 5 22 6 1 6 2 6 3 6 4 6 5 6 6 7 1 1 2 7 3 8 1 8 2 8 3 8 4 8 5 8 6 8 7 B 1 B 2 C 1 C2 65 Unsuccessful and successful attempt to connect lt lt lt 90 Structure of KPC3plus data packets lt lt lt 91 Screen shot of Hyperterminal while in manual drive mode 96 Screen shot of Hyperterminal sending waypoints 99 Screen shot of Hyperterminal requesting CoolRobots status 100 Screen shot of Hyperterminal requesting data from CoolRobot 101 Picture of the Campbell Scientific CR1000 datalogger 102 Picture of Z Worlds RCM3100 core module lt 103 Screen shot of FS2 sample program showing specifications of the Flash memory 105 Screen shot of Short Cut first step edit measurement interval 109 Screen shot of Short Cut second step choosing sensors 110
53. if else if off bearing gt 0 turning_tm int off_bearing 300 motor_speed 2 44 motor_speed 3 44 calculated off_bearing from initial course to waypoint END DESCRIPTION OKCKCKCKCk I I ck kck ck OK ke ke ke e x kx motor speeds are set to 100 motor speeds are set to 100 D 4 navigate lib 209 UpdateMotorOutput while i 1 costate waitfor DelayMs 1000 read sensors end costate costate waitfor DelayMs turning tm motor speed 2 60 motor speed 3 60 UpdateMotorOutput i 0 end costate end while end else if end function BeginHeader fendif EndHeader D 5 radiocomm e lib 210 D 5 radiocomm e lib Toni Zettl March 15th 2005 BeginHeader fuse GPS LIB EndHeader T TL T P PL Bg M LP o aM e L TT L T BeginHeader str2wayp int str2wayp char in str GPSPosition wayp extern int wp count extern GPSPosition wp list 100 EndHeader START FUNCTION DESCRIPTION KKKKK CK CC Ck C CK CK CI CI CI CC C C K x KK M A AA termStr radiocomm e lib gt SYNTAX int str2wayp char in str DESCRIPTION This function converts a string to datastructure GPSPosition and and place the waypoint s within the string in the global variable wp list PARAMETER1 Pointer to string up to 255 characters long e ETURN VALUE integer with number of w
54. int SwapBytes int value int i0 i0 value lt lt 8 amp OxFF00 put low byte into high byte 10 value gt gt 8 amp OxOOFF put high byte into low byte return i0 UT TT TT TTL LL L LL LL LL LL L LL L C BeginHeader SendToDAC void SendToDAC int message ifdef SPI SER fundef SPI SER define SPI SER D 1 1 endif ifndef SPI SI define SPI Sl endif ifdef SPI SER D use SPI lib endif EndHeader START FUNCTION DESCRIPTION ACkCkCk ck ck ck ck kck ck k ck ck k ck ck ck k ck k kk k kk kk D 2 drive lib 180 SendToDAC int message lt drive lib gt SYNTAX void SendToDAC int message O ESCRIPTION sends message to the MAX536 PARAMETER1 message wanted to be send to the MAX536 RETURN VALUE Gl NONE nN EY WORDS END DESCRIPTION OKCKCKCKCkCkCk ck I kc k Ck OK ke e x kx void SendToDAC int message WrPortI PBDDR amp PBDDRShadow OxFF PB all output BitWrPortI PBDR amp PBDRShadow 0 2 CS 0 enable CS on PB2 SPIWrite amp message 2 BitWrPortI PBDR amp PBDRShadow 1 2 CS y 1 disable CS TMM T T TL PCM P MP M E M MP P P Mel P P TTL L TTL BeginHeader UpdateMotorOutput void UpdateMotorOutput extern char display1 128 extern char display2 128 extern char display3 128 extern char display4 128 extern char fstring 256
55. it is checking if the modem is on and if this is true it will try to connect to the remote host by sending the connect command once to the modem The modem will now try to reach the designated remote host for approximately 1 minute After this time the robot will wait for an incoming connection and do nothing until it detects a connection to the remote host After a successful connection the robot switches to manual drive mode and can now be driven manually or switched to another drive mode If the modem was off on program start the controller is waiting until the modem is turned on and performs the same way as if it was on at start up If a loss of the connection is detected for any reason the robot will stop and wait until the connection is established again by the remote control 5 3 Controling the CoolRobot via radio link 94 The second version mainprog v0 35 is not as reliant on a radio connection as the first one It is also checking whether the robots modem is on or off at startup If the modem is off the robot will also stay inactive and wait until it is turned on After a modem on is detected the robot will immediately switch to waypoint following at full speed and start navigating toward the first waypoint The initial waypoints are stored in a string defined within the main program and are activated one start up of the program see chapter 7 1 and 7 2 Besides it will act quite similar to the first version of the main routine It wil
56. left turn if driving forwards and a left turn instead of a right turn if driving backwards direction of travel A C q The command q forces the robot to stop within a maximum time of two seconds It decreases all four motor speeds by 10 in a time delay of 200 milli seconds That means if driving with full speed it takes 2 seconds to come to a full stop but only 1 167 seconds for a full stop if driving at partial speed for example This function is also used to Figure 4 7 Overview of motor stop the robot if detecting a high tilt angle in drvie placement mode wp follow full 4 5 Perspective on further drive modes 64 4 5 Perspective on further drive modes Our task was to have an autonomous driving robot following waypoints But as the Cool Robot is driving along for weeks many interrupts can happen A blizzard can force the robot to turn into the wind or force it to stay at one point to recharge the batteries The following drive modes need to be implemented in the system in the future 4 5 1 Charge cycle jread the following sensors tilt sensors Wind speed sensor ground clearance Y sensor range interrupt new drive mode OK Slave charging new drive mode complete modem listen input send status Figure 4 8 Drive mode charge cycle The drive mode charge cycle will be necessary The robot is powered with solar energy which is not availab
57. like formation can be transmitted by virtually every radio 5 2 Radio Communication 84 Figure 5 9 shows the principle of frequency shift keying The first diagram shows 1300Hz and 2100Hz sine waves and diagram two a digital signal of altering 0 and 1 The last diagram shows the corresponding analog signal 0 1 39m 2 78m 4 17m 5 56m Figure 5 9 1300 2100Hz Freguency Shift Keying 5 2 1 4 Setting up the KPC3plus This part describes how to set up the KPC3plus including basic Wiring when connecting it to a computer or the Jackrabbit micro controller as well as connecting it to a transceiver Figure 5 10 provides a basic wiring overview For further information the KPC3plus manual is recommended 5 2 Radio Communication 85 KPC 3 Plus connections on back 3 V battery Radio Transceiver Computer or GPS Power DB 9 female DB 25 female 2 1 mm j 2 1 mm power jack and stranded 2 conductor wire 5 conductor shielded cable Shielded RS 232 cable Bench Power Supply 12 V de Power cube Power adaptor 120 V ac 12 V dc with cable assembly 120 V ac yobis Hicrophone Serial COM port DB 9 or DB 25 male Transceiver Computer Figure 5 10 Basic wiring of the KPC3plus radio modem To connect to the radio modem a computer w
58. normally the first flash is used as code space and the second flash is reserved for a file system There is a possibility to use parts of the first flash especially if it is the only flash device to install a file system but since the software for the CoolRobot uses program space of more than 130k there is not much space left to store data Figure 6 2 Picture of Z Worlds RCM3100 core module 6 1 Storage and retrieval of internal sensor data 104 We switched to the RCM3100 processor and now have up to 256k space for a file system and a lot of space for further software enhancements This theoretical value cannot reach 100 because some of the space is used internally for the data management of the file system The maximum number of files to be used as well as the desired logical sector LS size limit the actual space available A few big files are more efficient than a lot of small files because every file needs one sector for its metadata which is data used by the file system managment and therefore more files equal more memory used for the metadata The LS size also got a big influence on the efficiency of the used memory There is one sample program FS2INFO C included with the DynamicC package which checks the specifications of all memories at tached to the micro controller regarding the filesystem and displays the results as shown in figure 6 3 The test was performed on the RCM3100 board and the second Flash memory is shown as devi
59. of 51 Hz At frequencies higher BW Hz 3 14 than 51 Hz the attenuation is 40 2 The specific feature of a Butterworth Filter is that it dec has only one cut off frequency 3 3 4 Motor current and motor velocity sensors Eyes and ears of the Cool Robot that is a good transcription for the analog sensors and es pecially for the motor currents and the motor velocities The Cool Robot is powering all four motors in velocity mode The AMC brushless servo amplifiers try to keep the motors at the desired revolutions by increasing the current draw for each motor if it has to provide more torque In reality it is not possible to keep the revolutions at the exact same level If the Cool Robot climbs a sastrugi feature for example not all wheels will reach the inclination at the same time and one wheel has to produce more torque than the others As a result the current draw for that motor increases to keep the revolution up Meanwhile the revolutions for that wheel drop a little and not seeing the Cool Robot or the feature that is faced one can easily guess what the current terrain looks like The other way around the motor current and motor velocity sensor for one wheel can also detect a wheel not in contact with the snow The Cool Robot will be confrontated with driving with one wheel in the air frequently so that this will not be an extreme case But we want to be able to tell if the Cool Robot is high centered on a large sastru
60. pa rameter Whence defines relative to which point of the file the position will be set SEEK_SET is relative to the beginning SEEK END to the end of the file SEEK CUR starts at the cur rent position and SEEK RAW is a special case of seek end which allow to write data after the end of the actual file The parameter Where is used to add an positive of negative offset to the position For example fseek stestfile 10 SEEK SET will set the the read write position to the tenth byte of the file called testfile fread File Buffer Length fwrite File Buffer Length are very similar in their use Both functions will read write the number of bytes specified in Length from to logfile to from the character buffer pointed to by Buffer The reading respectively writing starts at the position set by fseek fclose File closes an opened file As an example the following lines will open a file called testfile with the file name defined in TEST FILE NAME append the character string stored in the variable buf fer to the file and close the file after writing fopen rd amp testfile TEST FILE NAME fseek amp testfile 0 SEEK END fwrite amp testfile buffer sizeof buffer fclose amp testfile 6 2 The Campbell CR5000 and CR1000 dataloggers 108 In the shown case no error handling is performed which means there is no guarantee that the data was really written to the file E
61. points received where 46d is replace by the value stored in wp rcvd The out string is sent using cof serEputs char as descirbed earlier Case 3 the answer to a status re quest is basically the same except another format string and four parameters instead of one Case 5 can be used by different functions the only have to write whatever they want to send toout string and set send event 5 At this point of the development this case is used to send all the navigation data produced in the library NAVIGATE LIB once every nav igation step The remaining case 4 the answer to a data request is a little more complex since it does not only send a fixed string It will try to open the logfile and read the last 32Bytes of data back to send them back If there is no actual logfile existing it will encounter an error while opening the file and answer to the request with the sentence could not open logfile instead of the last 32 stored Bytes If the file is opened successfully but there is no data to read or less than 32Bytes the answer will be no data found An important thing detail is the reset of send event to zero at the end of every case If this reset is missing the same data will be sent over and over again in pretty short interval which might jam the radio connection due to more traffic the given bandwidth can handle costate if status modem 2 switch send_event case 1 sprintf out_string d waypoints receivedNM
62. section since this keyword performs a jump out of the switch case statement If break is missing the following case will also be executed which might lead to fatal errors The different drive modes are introduced in detail in chapter 4 4 At the end of this piece of code the in string is flushed to prevent the execution of the same command a second time This would be fatal especially in manual drive mode since the last drive string would be used again and again until a new one is received 7 3 The main loop 127 7 3 3 The modem output block The modem output section is quite similar to the main control section since its main part is also a switch case statement that selects what kind of data is sent to the base station if an active radio connection is detected The principle is the same as with switching the drive modes depending on the integer value send_event holds one of at the moment four avail able routines for the output is executed Case one is activated if a number of waypoints is received and stored to wp list The function str2wayp char GPSPosition increments the variable wp_rcvd by one for every waypoint that is stored successfully and initializes the answer by setting send event 1 The function sprintf char char format parameters fills a formated string pointed to by format with the given parameters and writes it to a specified character array In the first case out string is filled with the string d way
63. section opens the serial ports C and E that are used for data exchange with the radio modem and the GPS unit The ports are opened using the function serXopen Baudrate where X can be a letter from A to F for the 6 available serial ports Af ter opening the ports the read and write buffers of each serial port are cleared using serXwr Flush and serXrdFlush The last few lines represent a test output to the radio modem using cof serEputs char a simple cofunction to output character strings to a serial port This is used to check if the modem is on or not If it is on it will respond with an output that indicates that it can not understand the entered command This answer is received and interpreted by the modem input routine which sets status modem 1 for modem on 7 3 The main loop 124 serEopen 9600 serEwrFlush serErdFlush serCopen 4800 serCwrFlush serCrdFlush costate wfd cof serEputs modem test r 7 3 The main loop The main loop is the heart of the control software since it is the part that is executed all the time when the micro controller is running The infinite loop itself is started by a while 1 statement Everything within the curly brackets is executed repeatedly as long as the value given in the round brackets is different for zero 7 3 1 The modem input block The modem input block is the smallest section of the main loop and it only purpose is listening f
64. side the inner diameter of the tube was enlarged a little bit to the bearings within Furthermore a groove for the retaining ring was milled to the very end of the tube The finished support tube was now glued to the mounts also using the two part epoxy After this step the whole drive train was mounted to the chassis beginning with screwing the shaft collars to the gear head then fitting the bearings to the support tubes and fastening them with the retaining rings Now the axles could be inserted and screwed to the shaft collars and finally the wheels were screwed to the axles As the rolling chassis was finished the electronic components were added to the chassis The motor controllers were mounted to the side walls of the chassis near their appropriate motor using two screws for each controller glued to the walls By the time we finished the assembly to a drive able robot the first test pieces of software were finished too One of them was a routine to adjust the output of the motor controllers via the DynamicC compiler window and keyboard inputs So we started first driving tests At the very beginning we droe just within the building but we soon decided to take it outside to check its maneuverablity speed and also the strength and flex of the chassis 12 Figure 2 6 shows photos from the first outdoor tests Figure 2 6 First moving test of Cool Robot After some testing with the robot the decision was made that the robot should be e
65. so on 7 2 Start up sequence initializing of variables file system and serial ports 121 The drive mode is initially set to manual drive mode drive mode 5 the status of the modem is determined as off status modem 0 and send event 0 represents nothing to send Command Value Meaning status modem 0 modem off 1 modem on disconnected 2 modem on connected to remote host drive mode 1 waypoint following full speed 2 waypoint following partial speed 3 got stuck mode 5 manual drive mode send_event 0 nothing to send 1 number of waypoints succesful received 3 answer to status request 4 answer to data request 5 send back navigation data Table 7 1 Overview of status variables The following section deals with the initialization of the filesystem and the creation of the logfile The first piece of code only checks if the storage device defined in LX_2_USEis available If not the program will be terminated with exit code 1 if LX_2_USE printf The specified device logic extent d does not exist Change LX_2_USE n int LX_2_USE exit 1 else printf Using device logic extent LX d n int LX_2_USE r Now the filesystem will be initialized using the function fs_init 0 0 The first parameters for this function must be zero and the second one is ignored anyway thus they don t change any thing If the file system could not be intialized for any reason
66. speed the robot checks the tilt angles the motor speeds and the motor velocities once every second If one of them is out of the range the robot is stopped and the drive mode is changed After driving around a high tilt angle or after getting out of a high centered position the robot will start the drive mode wp follow full again The same routine as described for the startup is executed to get back on the defined track chapter 3 2 During the whole time the robot is driving in wp follow full it can be interrupted and switched to the drive mode manual operator by sending the command CRCMDMANDM from the modem chapter 5 3 4 4 4 Waypoint following at partial speed The drive mode wp follow partial is implemented to guarantee a movement if the energy budget does not allow to drive the motors at full speed The motors are driven at 60 of the m sec maximum speed which is equal to a speed of 0 78 The drive mode will be called by a routine from the Slave microcontroller which handles the overall energy consuption and bud 4 4 The different drive modes of Cool Robot 62 get The main algorithm is the same as described in chapter 4 4 1 The difference to waypoint following at full speed is that the time between the navigation cycles is defined for two dif ferent situations If the drive mode is accessed through power restrictions the navigation time is set with tm_nav_low which is longer than in waypoint following
67. speed 0 motor speed 3 UpdateMotorOutput while i 1 t off bearing 300 88 motor speeds are set to 100 88 0 costate waitfor DelayMs 1000 read sensors end costate costate waitfor DelayMs turning tm motor speed 0 100 motor speed 3 100 UpdateMotorOutput i 0 end costate end while end else if end function T ULL ET BeginHeader turn partial D 4 navigate lib 208 void use turn partial float off bearing analogin lib EndHeader START FUNCTION DESCRIP turn partial off bearing navigate lib ION ACkCkCk ck kCk ck kCk ck kk ck ck kk A kCk ck X XK ck k ck ck ck ck ck ck k ck ck k ck ck ck k ck kk k kk kk degrees to right off bearing gt 0 SYNTAX void turn partial float off bearing DESCRIPTION makes a turn of off bearing or left off bearing 0 PARAMETER RETURN VALUE None aN EY WORDS void turn partial float off bearing auto int i long turning_tm i 1 if off bearing lt 0 turning tm int off bearing 300 motor speed 0 45 motor speed 1 45 UpdateMotorOutput while i 1 costate waitfor DelayMs 1000 read sensors end costate costate waitfor DelayMs turning tm motor speed 0 60 motor speed 1 60 UpdateMotorOutput i 0 end costate end while end
68. the data structure GPSPosition which is defined in the GPS LIB Thus it is im portant to include the GPS LIB before the others are included or the compiler will complain about dozens of errors because the data structure is used before it is defined A complete list of the used libraries and the functions they provide can be found in appendix A Table A 1 const char wp string CRWPT 3 4336 6000N07207 8000W 4336 9600N07208 0400W 4336 4800N7207 3800W const int motor_speed_increment 10 const int angle 20 char in_string 256 char buffer 256 char buf 1024 char out_string 256 char in_stri 128 GPSPosition wayp GPSPosition test point GPSPosition wp list 100 File logfile 7 2 Start up sequence initializing of variables file system and serial ports 119 nt wp_count nt wp_active nt wp rovd nt wp start nt drive mode nt status modem nt send event nt motor speed 4 Bt lp count nt tm count nt FSrc float dis bp H H p p p H H b b b H This part of the code declares all the global variables used within the program Global vari ables can be read and changed by every function within the program Thus it is possible to pass values back and forth between functions called either libraries or the main routine A good ex ample for such a variable is the integer drive mode It is used within the main routine to switch between the different drive modes for example drive mode 1
69. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 02 0 0 IAAL 3 1 E O JO 1 0 U V XO 00 U 00 00 U U I I O 0010 00 00 IO U 0 UE 06 1000 O JO JO JOJO 0 0 VJ 0 U U 00 0 0 0000000000000000000000000000000 060000 6 0 6 000 0060 000 00 00 000 124 7 126 8 128 9 120 3 180 0 197 8 215 9 210 1 214 4 209 3 211 4 208 9 210 1 214 6 210 1 208 0 224 9 220 5 205 8 210 8 212 2 221 5 210 1 2114 208 9 215 9 202 5 206 9 210 0 206 8 215 9 214 4 2143 206 9 222 1 290 4 298 5 296 9 3152 313 3 306 7 311 3 308 8 308 8 306 8 310 8 304 6 310 8 306 8 315 1 311 3 308 9 309 2 308 6 310 8 308 6 308 0 313 3 157 Table B 2 shows the test data from the waypoint following test on march 22nd aw cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl aw cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl aw cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl aw cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl RRRABRABRARREARA 337 984 4338 337 984 337 992 338 00 338 008 338 018 338 023 338 032 338 044 338 057 338 065 338 0748 338 0827 338 0882 4338 097 NEQVFOSNAEHSES 4337 92 338 0959 338 086
70. 03 4 217 7 270 0 122 1 159 cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl aw cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl 337 7479 337 7347 337 7318 337 7161 337 7015 337 6883 337 6805 337 6716 337 6607 337 6514 337 6432 337 6325 4337 62 337 6109 337 6031 4337 602 337 6144 4337 8 337 6194 337 6256 337 6324 337 6414 337 6477 337 6529 337 6612 337 6708 337 6762 4337 682 337 6887 337 6984 337 7043 337 7089 337 7173 337 7212 337 7261 337 7308 337 7386 337 7498 337 7643 337 7764 ZZ ZZZZZZZZZZZZZZZ ZZZZZ ZZ ZZ ZZZZZZZZZZZ 7208 819 7208 84 7208 865 7208 873 7208 879 7208 889 7208 893 7208 898 7208 906 7208 914 7208 918 7208 923 7208 932 7208 941 7208 964 7208 996 7209 019 7209 3 7209 034 7209 048 7209 059 7209 07 7209 084 7209 098 7209 114 7209 129 7209 143 7209 16 7209 178 7209 195 7209 203 7209 216 7209 229 7209 243 7209 259 7209 274 7209 291 7209 304 7209 309 7209 312 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 bp cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 cp2 43371 7573 4337 7386 43317 7332 4337 7234 4337 7099 4337 6968 4337 6883 4337 6784 4337 668 4337 6587 4337 6514 4337 6408 4337 6276
71. 075 7208 9149 7208 9235 7208 9295 7208 9374 7208 9447 7208 9526 7208 9609 7208 9678 7208 9742 7208 9824 7209 29306 7209 0102 7209 0277 7209 0435 7209 0607 7209 0699 7209 0791 7209 0918 7209 1005 7209 1098 7209 12 7209 1323 7209 1424 7209 1544 7209 1646 7209 1767 7209 1859 7209 1948 7209 2073 7209 2192 72092317 7209 244 7209 2561 7209 2711 dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw 0 070 0 054 0 037 0 015 0 612 0 578 0 553 0 535 0 518 0 502 0 485 0 467 0 450 0 430 0 413 0 396 0 375 0 354 0 331 0 311 0 290 0 272 0 251 0 234 0 216 0 197 0 176 0 155 0 132 0 115 0 092 0 075 0 059 0 042 0 022 0 489 0 464 0 441 0 414 0 398 0 380 0 359 0 342 0 325 0 309 0 287 0 271 0 249 0 233 0 211 0 195 0 178 0 158 0 135 0 114 0 092 0 066 0 045 Z S 8 8 S A A A A 4 4 S A A A A 4 A 4 A 4 4 S 4 4 4 4 4 4 4 A Z S 8 S S A A A S A A 4 A A A S 4 A 4 4 4 4 125 7 125 3 123 7 127 0 1 5 2 6 2 5 2 6 2 5 2 6 2 7 2 8 2 9 2 9 3 0 3 2 2 5 1 9 22 22 22 1 6 1 6 1 6 1 9 1 5 3 1 4 1 3 9 5 0 4 8 4 9 5 0 8 3 3 6 t2 2 DO 2 2 2 2 P2 2 9 2 2 P2 2 2 9 2 2 P2 2 D2 2 2 2 2 P2 2 2 2 2 2 0 2 1 1 2 0 1 7 1 7 1 9
72. 183 0 161 0 140 0 113 0 093 0 073 0 054 0 030 0 006 0 552 0 525 0 505 0 485 0 463 0 449 iz T ony a o i Qo oo 71 o W a to o OJBOR OR ON a o OLO 0 34 o Qo bo Pt e 0 29 0 27 0 25 0 2 0 19 0 17 0 13 0 1 0 104 0 084 0 068 0 053 0 031 0 008 o o U 0 6 0 56 0 5 0 5 0 49 0 44 o o e o o U ive o DAR RR oo pu Z NOW 4 XO OU UC 00 O XO UC UA o 0 36 0 34 0 320 0 294 0 276 0 256 0 238 0 212 0 189 0 169 0 145 0 117 0 095 0 074 0 052 0 034 0 011 0 501 0 472 0 444 0 418 0 405 0 379 0 355 0 334 0 312 0 289 0 262 S S E 2424224222228 S E E S K S E A S K S E AS K K S K S K S K S S 4 S E S E E S E 4 E AS K S K A S K S K S 4 S K 4 S 4 S E SE S S E S E 4 S 4 E 41 5 42 3 41 6 40 7 40 9 40 2 39 2 43 0 45 8 45 7 50 0 52 7 43 5 32 3 26 1 25 9 25 4 24 9 25 0 25 4 25 6 25 4 25 2 25 5 25 4 25 6 25 7 25 7 26 2 25 9 25 9 26 3 27 0 26 9 26 8 26 7 27 0 28 1 29 4 30 5 34 1 38 4 56 3 211 6 214 0 216 3 2154 2123 208 4 205 8 206 4 206 8 207 5 208 4 208 8 207 8 208 5 209 3 208 5 208 7 209 8 21 21 212 210 213 214 215 216 215 227 254 C o o0 Hud it 31 312 31 31 310 312 313 314 315 8 317 0 3173 DR wo NW OD to Secor soso r sro ror sss g cogocgccococogcgcocgogoccgcocgosgocsgcgosgcosgsg g cocgcoccococcgccgccocgcgcg
73. 2 338 0779 338 0703 338 0636 338 0599 338 0537 338 0453 4338 04 338 0356 4338 029 338 0249 338 0177 338 0125 338 0079 338 0008 337 9937 337 9892 337 9825 337 9755 337 9687 4337 964 337 9591 337 9549 337 9482 337 9437 337 9395 337 9326 337 9238 4337 62 337 9033 337 8905 337 8678 337 8539 337 8541 337 8671 337 8603 337 8492 337 8372 337 8285 337 8164 4337 804 337 7941 337 7828 4337 771 337 7596 337 7505 4337 14 337 7301 337 7175 337 7065 337 6979 337 6856 337 6717 337 6619 4337 652 4337 643 337 6329 4337 622 4337 8 337 6195 337 6277 4337 642 337 6513 337 6567 337 6619 337 6682 337 6733 337 6797 337 6863 337 6966 ZZZZZZZZZZZZZZ Z ZZZZZZZZZZZZZZZZ ZZ ZZ ZZZZZZZZZZ ZZ Z ZZ ZZZZZZZZZZZ ZZZZZZZZZZZ z ZZZZZZZZZZ 7209 261 7209 12 7209 261 7209 255 7209 241 7209 229 7209 218 7209 209 7209 197 7209 191 7209 181 7209 17 7209 162 7209 152 7209 136 7209 123 7208 76 7209 094 7209 079 7209 068 7209 058 7209 044 7209 034 7209 019 7209 005 7208 996 7208 985 7208 973 7208 962 7208 949 7208 938 7208 927 7208 916 7208 902 7208 891 7208 877 7208 864 7208 852 7208 842 7208 832 7208 822 7208 809 7208 8 7208 789 7208 775 7208 763 7209 7208 759 7208 748 7208 748 7208 77 7208 796 7208 815 7208 839 7208 843 7208 848 7208 85 7208 853 7208 86 7208 873 7208 878 7208 883
74. 3 2 Main program for autonomous navigation 24 The navigate function is the heart of the navigation algorithm It is a function called from the drive mode wp follow full or the drive mode wp follow partial in certain time distances It makes the decision for a course correction see chapter 4 4 for description of drive modes The NMEA GPS data string is assigned to the function and the data string has to be parsed Therefor the function gps get position in the gps lib is called The function compares the string header with the known NMEA messages in our case GPRMC If the header does not match any of the known messages the function returns 1 as value If the GPS data string is not valid because the receiver is not tracking enough satellites the function returns 2 If the header is known and the data string is valid the function now parses the position data and stores it in a variable with the structure GPSPosition defined in the gps lib The structure GPSPosition consists of int current pos lat degrees float current pos lat minutes char current pos lat direction int current pos lon degrees float current pos lon minutes char current pos lon direction Table 3 3 Sample structure GPSPosition current pos That makes an easy access to the integer part of the latitude and longitude possible current position gt lat degrees The most important thing for the navigation algorithm is a correct trans
75. 31 0 30 1 30 4 28 7 29 3 28 6 26 7 25 0 24 7 21 5 0 0 125 8 125 9 125 9 125 8 125 8 125 9 125 9 125 9 125 6 125 7 125 5 126 0 126 0 126 1 126 1 125 9 125 8 125 6 124 3 124 5 124 0 124 4 124 6 125 0 125 5 0 443 0 419 0 401 0 376 0 355 0 338 0 312 0 291 0 266 0 239 0 220 0 189 0 167 0 142 0 122 0 099 0 079 0 054 0 035 0 576 0 548 0 523 0 502 0 485 0 468 0 450 0 435 0 4 0 40 Uo a to a UU MO ou 0 S JO o R O5 0 36 0 34 0 3 0 30 0 28 o 0 24 to P 0 2 0 19 0 17 0 14 0 13 0 1 0 09 35 4 35 1 34 4 35 0 34 9 33 9 33 7 32 0 30 7 30 5 29 6 29 8 28 1 28 5 27 7 25 5 23 6 22 6 18 2 37 4 27 0 27 2 27 2 27 2 27 2 27 4 27 4 27 5 27 3 27 5 27 4 28 0 28 1 28 3 28 4 28 4 28 5 28 5 27 5 28 0 28 0 29 0 29 8 31 0 32 6 O0O0O0O0G0GO0GO0O0O0nR0o0a0co0o00000 O0O0O0G0GO0G0GO0O0G0O0RonR0o0o0o0onocon0000n00 NO 00 1 100 00 00 dou 00000 IO JO 100 O0 00 2100 00 I O00 OV tA 00 ON 00000000000000000000 00000000000000000000a0000co0 512 37 5 49 6 30 1 373 533 30 0 554 43 1 34 6 41 0 25 8 44 9 21 6 34 3 37 3 32 7 25 8 30 7 30 6 20 6 24 6 26 4 26 7 26 8 22 7 27 0 26 8 31 3 22 7 29 6 20 6 26 7 24 6 26 6 29 2 26 6 28 8 42 6 18 5 29 2 22 5 22 3 22 7 22 7 156 cpl cpl cpl cpl aw cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl
76. 4 65 4 523 ETO TDOCOHIGEGU a aod a ot tn XD dO RECHT PE Sar oba vloha lodi Bee 66 CONTENTS iv 5 Communication of CoolRobot 67 5 1 IRIDIUM Communication lle 68 5 1 1 The A3LA IIRIDIUM modem 70 5 1 2 Prospect on further use 5 sd sce oe ee eS SURE d 81 5 2 Radio Communication uad uox 34 l dok oto SONT PT Faw 8l 5 2 1 The Kantronics KPC3plus packet radio modem 83 5 3 Controling the CoolRobot via radio link lt 92 5 3 1 Establish and terminateaconnection len 93 5 3 2 Manual drive mode se L Ao tg zad epe oe toa dos 95 5 3 3 Waypoint following e uuu ore Rr e Se Relea Koes Eoin al ici i ad Ata 97 5 3 4 Other commands and functions lll 98 6 Data storage 102 6 1 Storage and retrieval of internal sensor data s 103 6 2 The Campbell CR5000 and CR1000 dataloggers 108 7 Software frame work 115 7 1 Definitions libraries and variable declarations 116 7 2 Start up sequence initializing of variables file system and serial ports 119 Jad Bie dai IGO S i dce eo Dette BBE SA ed d ER p A ee 124 7 3 1 The modem input block 154 2 SS aS Baw eS wae 124 7 3 2 The main control Block 2 Bye 8 ku Space Sod GR eo ox hes 125 7 3 3 The modem output block lt lt lt lt 44 lt 4 127 7 4 Different versions of the main programm lt lt lt 130 8 Results of the moving test
77. 4337 6177 4337 6064 4337 6014 4337 6079 4337 6504 4337 616 4337 6216 4337 6274 4337 6353 4337 6434 4337 649 4337 6557 4337 6645 4337 6724 4337 678 4337 6846 4337 693 4337 6984 4337 7054 4337 7114 4337 7185 4337 723 4337 7278 4337 7338 4337 7436 4337 7563 4337 7685 ZZZZZZZZZZZZZZZZZZZZZZ Z ZZZZZZZZZZZZZZZZZ 7208 817 7208 83 7208 854 7208 872 7208 874 7208 882 7208 889 7208 894 7208 9 7208 908 7208 914 7208 92 7208 927 7208 934 7208 954 7208 977 7209 011 7209 08 7209 022 7209 04 7209 051 7209 062 7209 074 7209 088 7209 104 7209 12 7209 132 7209 148 7209 167 7209 186 7209 195 7209 205 7209 22 7209 232 7209 249 7209 264 7209 282 7209 298 7209 307 7209 311 Z S 5 A S A A 4 A A S 4 A 4 288 Z S 8 A S 4 A S A 4 4 A 4 A S 4 A 4 4 4 4 0 338 0 301 0 275 0 246 0 222 0 196 0 181 0 167 0 146 0 128 0 117 0 106 0 090 0 080 0 056 0 034 0 028 0 489 0 467 0 448 0 426 0 405 0 384 0 358 0 332 0 312 0 289 0 264 0 236 0 220 0 204 0 180 0 164 0 149 0 133 0 115 0 094 0 068 0 047 SS E S E S E 4 E S K S 22228 ZE E S E S E E S K S S KS K S S S K K 225 7 2253 221 22 223 7 2273 229 7 231 8 2354 238 8 243 2 248 7 257 6 270 0 282 6 303 4 350 7 68 1 313 3 313 9 313 9 313 7 314 3 315 1 315 9 316 1 317 3 319 3 321 4 322 9 323 7 326 1 328 1 3322 337 6 345 3 354 1 2 3 10 0 18 9
78. 8 0715 4338 0659 4338 0605 4338 0554 4338 0498 4338 0428 4338 0374 4338 0309 4338 0248 4338 019 4338 0134 4338 0077 4338 0024 4337 9969 4337 9909 4337 981 4337 9747 4337 9677 4337 963 4337 9584 4337 9529 ZZZZZZZZZZZZZZZZZZZZZZZZZ Z ZZZZZZZZZZZZZZZZZZZZ 7209 12186 7209 3244 7209 3096 7209 3019 7209 2892 7209 2821 7209 2738 7209 2587 7209 248 7209 2327 7209 2204 7209 2123 7209 2001 7209 1899 7209 1776 7209 1714 7209 1618 7209 1522 7209 144 7209 1375 7209 1283 7208 76205 7209 1012 7209 0858 7209 0736 7209 0612 7209 0505 7209 0401 7209 0296 7209 0199 7209 0099 7208 9984 7208 9875 7208 9748 7208 9595 7208 949 7208 939 7208 9282 7208 9182 7208 9079 7208 8985 7208 8855 7208 8713 7208 8585 7208 8471 7208 8368 7208 8258 dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw dw 0 444 0 421 0 403 0 378 0 356 0 339 0 313 0 293 0 267 0 240 0 221 0 191 0 169 0 143 0 123 0 100 0 080 0 055 0 036 0 013 0 542 0 517 0 497 0 479 0 462 0 444 0 429 0 413 0 397 0 373 0 358 0 335 0 312 0 294 0 277 0 261 0 243 0 227 0 211 0 185 0 164 0 141 0 125 0 107 0 089 2222222222222 4 4 4 4 E 4 Z S 8 8 A S A S A A A A S 4 A A A S 4 A A 4 4 4 35 6 353 34 7 353 35 2 34 2 34 1 32 4 31 1
79. 9 for Count 1 Count lt Samples Count loop for averaging the number BitWrPortI PDDR amp PDDRShadow 0 0 enable CS SPI BWrRd Command amp data 2 write the command to the ADC an BitWrPortI PDDR amp PDDRShadow 1 0 disable CS data 0 OxOF amp data 0 extract the first four address bits data one data 0 256 data 1 convert the conversion result into an i if data one 2048 data_one_comp data_one 61441 data one Ox0FFF amp data one comp data one data one comp end if data all data one update accumulator for data one comp 0 data one comp lt 100 data one comp cheap time delay end for Voltage float data all Samples end function TITTTTTTTTTTTTT TITS I TTT TTT T TTT T TTT T TT TTTAAATTATTTT TTT T TT TTT TTT T TTT T TT BeginHeader read_sensors void read_sensors fuse SPI B lib fuse drive lib extern float scale motor extern float scale tilt extern float scale velocity extern float output 15 EndHeader loat scale motor scale factor for motor currents loat scale tilt scale factor for tilt sensors loat scale velocity loat output 15 Fh Fh Fh Fh START FUNCTION DESCRIPTION KKEKKKKKKKKKKKKKKKKKKK KKK AA ko ko ck void read sensors analogin lib SYNTAX void read sensors DESCRIPTION will command the A D to ta
80. BRead SPI_BWrite drive lib radiocomm_e lib drive lib drive lib drive lib drive lib gps lib drive lib drive lib navigate lib radiocomm_e lib analogin lib analogin lib drive lib analogin lib analogin lib drive lib SPI B lib SPI B lib SPI B lib 150 SPI_BWrRd stop str2wayp SwapBytes termStr turn_full turn_left turn_partial turn_right UpdateMotorOutput wp_follow_full wp_follow_partial SPI B lib drive lib radiocomm e lib drive lib radiocomm e lib navigate lib drive lib navigate lib drive lib drive lib drive lib drive lib A 1 Overview of parameters and variables 151 A 1 Overview of parameters and variables angle main prog Constant integer to set the turning difference for manual drive mode in percent The two wheels on one side slows down for angie and the other accelerates for angle default 20 bp_range navigate lib A float to set the radius for the circle around a basing point Once within that range the next basing point will be generated and the robot will change its heading The range is the value in km default 0 045 dis_bp main_prog A float to roughly set the distance between two basing points The distance between two waypoints will be divided by that value The return value is rounded off to an integer and is the number of basing points on the track between the two waypoints If the value is 0 5 the distance between two basing points could be 468 m or 512 m
81. IVE The receiver is running through its normal housekeeping routines developing new fix data etc but it will not send any of this data out of the serial port until it is requested Motorola WinOncore12 Command Monitor Window E File View Options Window Help t Communications Lo PC Communications Ebel General Setti RTCM Comm Set a Open ense enge BI Seu Mon Msg Timing About NMEA Settings tot Define New Message S amp d Command Manager Timing Settings Satellite Settings 2 ES MR AE Enable Position Hold Enable Site Survey Enable Motorola Protocol w Enable NMEA Protocol Figure 3 4 Options to initialize the GPS unit to output NMEA data 3 1 GPS Navigation 20 Using the software Winoncore the receiver can be initialized easily by selecting the desired output format and rate from once a second to once every 9999 seconds After setting the output format NMEA Protocol has to be enabled Figure 3 4 The GPS data string sent to the serial port is displayed in the command monitor window Figure 3 5 and accessed by Cmd Mon The receiver now is ready to be connected with serial port C on the Jackrabbit microcontroller Figure 3 7 L Motorola WinOncore12 Command Monitor Window FE File View Options Window Help er m A A E Open Signal Navigation Survey Satellites Cmd Mon Msg Timing About gt i 9 ea o on 5 ados E ee fo t kB SGPRMC 152558
82. KKKKKK lib D 2 drive lib 185 nN EYWORDS O ESCRIPTION PARAMETERI PARAMETER2 RETURN VALUE Gl SEE ALSO END DESCRIPTION OCKCKCKCKCkCk Ck kCK Ck kCKCkCk KCkCkCK kok k A Ck kc k k kc kok ck kck ck k kk kk I I x ke int wp follow full int count invalid costate waitfor DelayMs 2000 getgps in stri if wp start 0 count_invalid 0 while count invalid 60 costate waitfor DelayMs 1000 count invalid getgps in stri if gps get position amp curr p2 in stri 0 break if gps_get_position amp curr_p2 in stri 1 sprintf out_string GPS parsing error n r send_event 5 end if if gps_get_position amp curr_p2 in stri 2 sprintf out_string GPS sentence invalid n r send_event 5 end else if if count invalid 60 drive_mode 5 return 0 end if end costate end while D 2 drive lib 186 end if forward full read sensors end costate costate waitfor DelayMs 1000 sensor_range sensor_high_centered tm_hc wheel_air end costate costate waitfor DelayMs tm nav 1000 navigate in stri end costate end wp_follow_full U UT LL TT BeginHeader wp follow partial void wp follow partial EndHeader START FUNCTION DESCRIPTION CKkCkCk c
83. M PARAM in NM RETUR 1 et position X int gps ge RDS gps IPTION Pars function is ab entence format ETERI newp ETER2 sentenc EA 0183 format N VALUE go parsing error 2 SEE A sentence mark iSO END D ESCRIPTION auto ine cw CG lt gps lib gt t position GPSPositon newpos char sentence S a sentence to extract position data le to parse any of the following s GGA GLL RMC os a GPSPosition structure to fill e a string containing a line of GPS data Success d invalid KOKCKCKCKCkCkCKCkCkCkCkCkCKCkCk CK kok k kok kok k kok CK Ck k Ck k k Ck k kc k kck ck kok ck k kk kok ke e I can parse GGA GLL or RMC sentence int gps get position GPSPosition newpos char sentence auto char togg 5 auto char dummy if st retur rlen sentence til lt 4 if strncmp sentence SGPGGA 6 0 D 3 gps lib 191 parse GGA sentence for i 0 i lt 11 i sentence strchr sentence if sentence NULL return 1 sentencet first character in field pull out data if i 1 latitude if gps parse coordinate sentence amp newpos lat degrees amp newpos lat minutes return 1 get coordinate failed if i 2 lat direction newpos gt lat direction sentence if i 3 longitude if gps_parse_coordinat
84. PBDDRShadow OxFF PB all output SPIinit while ch serCgetc Xn start while Copy only valid RCV d characters to the buffer if ch 1 buffer gpsl i ch endif end while buffer gps i ch copy Nr to the data buffer buffer gps i 0 terminate the ascii string return buffer_gps end getstring BeginHeader fendif EndHeader D 4 navigate lib 201 D 4 navigate lib BeginHeader ifndef NAVIGATE LIB define NAVIGATE LIB duse gps lib fuse drive lib EndHeader START LIBRARY DESCRIPTION Ck CK Ck Ck kk Ck CK Ck Ck CK CC CK C AZ AA AA A ZK CI Ck Ck kk S K KA x KA ko ko ko 21mar2005 navigate lib Goetz Dietrich 2005 changed routine for having invalid string stops after wp count 1 th waypoint and manual drive mode sends back cp 2 changed startup navigate turn full turn partial END DESCRIPTION OKCKCKCKCKCkCKCk kCK Ck kCK Ck k CK CkCkCKCkCkCKCkCkCKCKCkCKCkCk Ck k Ck k kc k kck ck kck ck kok kk ok ok k kok ke x e e e kx BeginHeader navigate int navigate char in strie extern GPSPosition start p extern GPSPosition curr pl extern GPSPosition curr p2 extern GPSPosition active wp extern GPSPosition last wp extern GPSPosition basing p extern GPSPosition wp list 100 extern float initial dist extern float dist to wp extern floa
85. PI dummy2 float dummy 2 PI lon d lon d dummy2 lon d lon d PI lat d lat d 180 PI if lat d 0 bp gt lat direction S S else bp gt lat direction N dummy int lat g bp gt lat degrees dummy lat d lat d float dummy 60 bp gt lat minutes lat d lon d lon d 180 PI if lon d lt 0 bp gt lon direction E else bp gt lon direction W dummy int lon d bp gt lon degrees dummy lon d lon d float dummy 60 bp gt lon minutes BeginHeader getgps C START FUNCTION DI har kkk getgps in_str S N U PARAMET YNTAX EYWORDS ESCRIPTION ERI I E ALSO Led ETURN VALUE gps lon d getgps char buffer gps EndHeader lt gps lib gt char getgps in str gets gps data string from serC string to put string from modem sin dist cos lat d cos tc1 PI ESCRIPTION ACkCkCk ck kCk ck ck KA K A k ck ck A X KA k ck ck k ck ck k ck ck ck kk ck kk ck k k kk kk D 3 gps lib 200 END DESCRIPTION OKCKCKCKCKCKCk Ck kCK Ck kCKCkCkCKCkCkCK Ck kCKCkCkCKCkCk CK CkCkCK Ck kCk Ck k Ck kck ck kck ck k kk K kk kok I I char getgps char buffer gps auto Ant a ch m serCwrFlush serCrdFlush memset buffer gps 0x00 sizeof buffer gps i 0 m 0 WrPortI PBDDR amp
86. S receiver is connected to the alternate RS232 pins for serial port C on the Jackrabbit J5 rxc pin4 txc pin6 gnd pin9 The connector for the receiver is a standard 9 pin serial connector and wired as shown 3 1 GPS Navigation 22 DB 9 connector pin 5 GND Honan fe 2 7 OOO pin 3 txc sdin GPS OOOO OOOO pin 2 mxc sdout GPS male male looking at pins wiring side Figure 3 7 Connector M12 3 2 Main program for autonomous navigation 23 3 2 Main program for autonomous navigation The navigation function navigate is written in the library navigate lib and follows the flowchart get current position get active waypoint get distance to waypoint in Figure 3 8 get next waypoint distance to distance to waypoint waypoint 10m bearing to waypoint distance to basingpoint bearing to basingpoint distance to basepoint 20m calculate new basingpoint yes distance to basingpoint bearing to basingpoint calculate current distance calculate current bearing calculate offset from track distance to wayp lt dist to basep yes pe calculate off bearing bearing to wp curr bearing calculate off bearing bearing to bp curr bearing aff bearing 4 or off track gt 20 e make a off bearing degree turn Figure 3 8 Flowchart for basic navigation algorithm
87. ST OF TABLES ix 5 14 Components of navigation data string 97 5 15 Overview of commands to enter switch drive modes 99 6 1 Possible values for the ResultCode lt lt lt lt a 112 6 2 Possible values for BufferControl lt lt lt lt lt llle 113 6 3 Possible values for DataFormat lt lt lt lt lt 44 114 7 1 Overview of status variables 2 3 2x oda eX E33 See E E 121 8 1 Parameters for waypoint following at full speed 22 mar 137 8 2 Distances and bearings for the waypoints lake mascoma bridge 138 8 3 Parameters for waypoint following at full speed 24 mar 140 8 4 Overview of distances ees 142 LIST OF SYMBOLS x List of symbols and abbreviations ADC Baud bp char cp 1 DAC DIN DOUT DSR DTE DTR float GPRMC GPSPosition GSM ICD GPS 200 Analog to Digital Converter One signalling element per second basing point 8 bit character current point for navigation use last current point used for current bearing Carriage Return also Nr Chip Select is used to start a conversion on the selected channel Clear To Send A flow control signal in serial interfaces Data Carrier Detect This signal indicates a connection to the far end modem for data transfer Digital to Analog Converter Digital Input for a serial port Digital Output line for a serial port Data Set Ready Another flow
88. UPLICRTION PROHIBITED WITHOUT PERMISSION OF KRNTRONICS cmd _ Figure 5 14 AUTOBAUD routine running on Hyperterminal Once this character is typed and sent to the modem by hitting carriage return all commands and data for the KPC3plus must be terminated by a carriage return character lt CR gt the modem is able to detect the baud rate used by the terminal it is connected to This baud rate is stored and can only be changed by erasing the modem settings memory by setting and resetting jumper J11 On the next startup of the modem it will run the AUTOBAUD routine again and the baud rate can be changed After completing AUTOBAUD the modem asks for a callsign which will also be stored in the KPC3plus and used until it is changed The callsigns for the two modems used are MAHONY for the modem on the Cool Robot and GOEK for the modem used with a PC These can be changed easily typing MYCALL lt desired callsign gt lt CR gt 5 2 Radio Communication 89 KPC 3000 HyperTerminal File Edit View Call Transfer Help De 3 DA E KANTRONICS KPC3PMM VERSION 9 0 C COPYRIGHT 2002 2003 BY KANTRONICS INC ALL RIGHTS RESERVED DUPLICATION PROHIBITED WITHOUT PERMISSION OF KANTRONICS cmd mycall MYCALL CROBOT cmd mycall goek cmd mycall MYCALL GOEK cmd Figure 5 15 MYCALL command using Hyperterminal As soon as the callsign is set the KPC3plus is ready for sending packet data There are dozens of f
89. a negative value causing a left turn and a positive value causing a right turn and a bearing is generally measured clockwise To avoid imprecise turning angles I limited the maximum turning angle for one 3 2 Main program for autonomous navigation 29 navigation cycle to 90 The current position after finishing the turn is stored and parsed into current point 2 for the next navigation run The robot now travels straight ahead for 30 seconds to start the next navigation cycle with current point 1 The distance between current point 2 and current point 1 is calculated to determine the current bearing Traveling with a maximum speed of 1 25 m s the distance should be greater or equal 30 m That is accurate enough for the gps receiver s position data Figure 3 13 points out the necessity for basing point generation offset from the track basing point range Figure 3 13 Example startup navigation drawing The current bearing on navigation cycle 2 is almost equal to the bearing to the active waypoint but varies from the bearing to the basing point If the robot would head to the waypoint no course correction would be made and the robot would travel on a path parallel to the calculated track With basing points the traveled path is more predictable because the robot makes more course corrections towards the calculated course If the robot reaches a distance of less than 20 m to a basing point the next basing point on the t
90. a word Figure 3 18 shows an example conversion request on serial port B Fi amp Cancel Print Figure 3 18 Sample SPI communication on serial port B PRINT_O1 Channel 1 is PC4 the serial data output of the jackrabbits serial port B sending two 16 bit data words and channel 2 is the C S being pulled low for the transmission Logic one is 3 3 V and low is 0 V The problem here was that the microcontroller has four SPI ports A B C and D but dynamic C only provides SPI library code for the use of one SPI port at a time The desired serial port has to be enabled to transmit data and with the use of the SPI functions it is not possible to enable more than one serial port There is the possibilty to change the definition of the SPI port in the function but the DAC needs a logic high all the time not to update the output value If the SPI port would be changed to serial port B instead of serial port D for the DAC the output for all four motors would change to 2 9 V which is equal to a motor speed of 100 3 3 Analog sensors 41 So I had to rewrite the SPI lib library into a library called SPI B lib to make a simultaneous use of two serial ports possible It uses the same code but only renamed functions for writing to or reading from a serial port see Table A lin App A For taking readings from the ADC the function to write and read data is SPI BWrRd command data 2 The original SPI lib is used to interface the DAC to
91. analog input channels The AD7490 evaluation board is build to be used with the Eval board controller from Analog Devices When using it with the Eval board controller all supplies are provided through the 96 way connector When using the evaluation board as a stand alone unit the external supplies must be provided to the alternate pins For connections of power supplies that are provided to the board for interfacing the Jackrabbit microcontroller on serial port B see Table 3 7 For using the evaluation board as a stand alone unit 5V must be connected to Vpp to sup ply the AD7490 and the on board high precision reference If interfacing the board with 3V systems 3V can be connected to the Vz pin Usually the supply voltages for the op amps 3 3 Analog sensors 39 digital supply voltage Vpp J7 digital ground Denp J7 analog supply voltage AVpp J2 analog ground AGND J2 positive op amp voltage 10V J3 negative op amp voltage 5V J3 Table 3 7 EVAL AD7490CB power supplies are 12V but the supplied voltages of 5V and 10V availablefrom the housekeeping power distribution board on the robot are within the desired range of 18V lt Vy lt 4 5V and 4 5V lt Vpos lt 18V The evaluation board has 19 switch and 19 link options to adjust the desired functions For operation with the Jackrabbit microcontroller the switches and links have to be set as shown in Table 3 8 Link No Function LKO LK15 Adds a 50
92. and is powered by a multi panel solar array The task was to build an Autonomous Mobile Robot which can be released at the South Pole station and traverse on the Antarctic Plateau during the austral summer within a range of 500 km in a time of 2 weeks without any maintenance That is possible because the robot is pow ered by renewable energy the sun The Antarctic Plateau gives very good reasons for using solar energy During the austral summer month the direct insolation from the sun averages 1000 W m Also the reflected sunlight by the large flat snow areas is significant The robot should have an empty mass of less than 75kg and should fit in the Twin Otter aircraft Figure 1 2 shows the completed robot chassis Figure 1 2 CoolRobot climbing sastrugi feature The basis for our work was the Diploma Thesis from Guido Gravenk tter and Gunnar Hamann 4 and the honor s thesis of Alex Price 5 Reference 5 deals with the conceptional work on the robot and the major influence on the design of a solar powered robot Hamann s and Gravenkoetter s contribution was to prove the viability of the project They tested different components such as the brushless dc motors the li ion batteries and the power supply in a cold chamber to see the influence of cold temperatures down to 40 C The conclusion was that the new generation of solar panels will provide enough energy needed for the propul sion The other conclusion of 4 was that the navigatio
93. and variable declarations 118 eter MY LS SHIFT is used to determine the size of the logical sectors LS used in the file system The LS size got influence on the efficiency of the file system and maximum available space compare Figure 6 3 This parameter can take values of 2 Bytes In our case the ex ponent is chosen to be 9 which equals a LS size of 1024Bytes and achieves most efficiency for our file system The last of those four lines defines a file name for our logfile In FS2 the actual file names are numbers between 1 and 255 The file name for our logfile is set to 1 LX 2 USE 2 The SPI CLOCK DIVISOR devides down the internal clock of the micro controller by the specified factor here 10 for the use as serial I O clock The next four lines only set the size of input and output buffers of the serial ports C and E The size must be defined to a value of 2 7 Bytes otherwise they are defaulted to 31Bytes and a warning is displayed when compiling the program For our application the buffer size are quiet big with 511Bytes and 255Bytes because the serial inputs form the modem serial port E and the GPS unit serial port C are character strings with sizes up to 256 characters respectively around 100 characters The included libraries listed in the next 5 lines Sometimes it is important to include the li braries in the right order for example the libraries NAVIGATE LIB and RADIOCOMM E are using
94. at full speed because the robot needs more time to travel the same distance The same shape of the track should be achieved To have the same distance between current position 1 and current position 2 tm_nav_low is calculated automatically to tMpav low sec 1 67 tMpnav sec The drive mode wp_follow_partial is also accessed if the Cool Robot reaches the last way point within a certain distance Then the robot is slowed down and the time between two navigation cycles is short to allow the robot to get very close to the waypoint If navigating with full speed the distance between two navigation cycles is greater than 30 m That makes it hard or impossible to reach a certain point within a range of 10 m So the robot changes to partial speed once within a range of 100 m of the last active waypoint in the list The time between two navigation cycles is set in tm_nav_wp and set to 10 seconds 4 4 3 Manual Operator The drive mode manual_operator gives the user the ability to control the robot manually with the keypad of a laptop or computer with radio connection within a range of 1 2 km 0 78 miles Is implemented to be able to drive the robot out of a garage for testing or any other purposes The functions for the manual control are written in the drive lib They split the range of negative full speed to positive full speed into 20 steps Every hit on the keypad is equal to a 10 change of the motor speeds The robot is accessed wi
95. at the software for the communication system itself is running but communication itself was fairly unstable due to the weak radio connection The maximum range of operation only was approximately 300 meters in a really flat environment without any obstacles and on a clear day When switching to the new radios these problems disappeared and we were able to run the robot easily in manual drive mode as well as in waypoint following at full speed In the first place we were a little bit concerned about the large amount of navigation data in combination with the low bandwidth 1200bit s of the radio link But this worked out just fine since the navigation algorithm takes about 30 seconds for each cycle there is enough time to transmit even the big set navigation data Sending one set of the navigation data takes all in all ap proximately 3 to 4 seconds When running in manual drive mode most of the time there is not a really significant delay between sending a command from the Hyperterminal window until it is executed by the robot In most cases this is not perceptible only when trying to send a command while the robot is sending back its actual motor speeds or when sending two commands back to back it may take up to 3 seconds until the command is executed because the first transmission blocks the channel for a certain time and only after this data exchange is finished the next packet of data can be transmitted Therefore it is more effective to send one
96. aypoints RETURN VALUE 0 GPS parsing error 1 sentence marked invalid 2 correct function 3 reached last waypoint KEY WORDS END DESCRIPTION OKCKCKCKCkCKCk ck kCk Ck kCk Ck k ck k kc k k kc k kck I ck ko ke ke ke e x kx p nt navigate char in strie int count invalid turn lim float wp range float bp range count invalid 0 D 4 navigate lib 203 wp range 0 030 bp range 0 045 turn lim 90 while count invalid GPS inv limit costate waitfor DelayMs 1000 count invalid getgps in strie if gps get position amp curr pl in strie 0 break if gps get position amp curr pl in strie 1 sprintf out_string GPS parsing error n r send_event 5 end if if gps_get_position amp curr_pl in strie 2 sprintf out_string GPS sentence invalid n r send_event 5 end else if if count_invalid GPS_inv_limit drive_mode 5 return 0 end if end costate end while if gps get position amp curr pl in strie 0 active wp wp_list wp_active if wp_start 0 only once at startup curr_p2 curr_pl initial dist gps ground distance amp curr pl amp active wp initial bearing gps bearing amp curr pl amp active wp initial dist dist bpdiv initial dist dis bp dist bp initial dist dist bpdiv gps basing point amp curr pl amp basing p initial bearing wp
97. aypoints successful written to wp list if an error occured o A EY WORDS string waypoint GPSPosition convert END DESCRIPTION OKCKCKCKCkCkCk ck I OK ke e x kx int str2wayp char in str GPSPosition wayp int wp number i written wp GPSPosition wp list 100 char buff 256 printf sWMn in str in str strchr in str 1 pointer locatet to first char after first memcpy buff in str 1 get number of waypoints buff 1 N0 wp number atoi buff for i1 0 i lt wp_number i in str strchr in str 1 pointer to first char of waypoint printf sWMn in str memcpy buff in_str 12 copy lat ddmm ssss to buff buff 12 0 terminated buff with NULL if gps_parse_coordinate buff amp wayp gt lat_degrees amp wayp gt lat_minutes 1 return i D 5 radiocomm e lib 211 memcpy buff in str 10 10 copy lon dddmm ssss to buff buff 10 N0 terminate buff with NULL if gps parse coordinate buff amp wayp lon degrees amp wayp lon minutes 1 return i in str in str 9 pointer to lat direction if strnemp in str N 1 0 strnemp in str S 1 0 wayp gt lat_direction in_str write lat_direction to wayp else return i in str in str ll pointer to lon direction if strnemp in str W 1 0 strnomp in str E 1 0 wayp gt lon_
98. been tested some more and some less They are all running the way they were supposed to without any runtime or system errors The first tests were executed using slightly different software because the development and improvment was still ongoing As soon as the Jackrabbit core module with the larger memory arrived we did a couple of test runs with the mainprogV0 34 and few with version 0 35 Unfortunately this core module as well as the evaluation board fell prey to a short circuit and we had to order a new one which only just arrived Thus the testing meanwhile had to happen with the 7 4 Different versions of the main programm 134 smaller micro controller and without the ability to store data locally on the controller which forced us to use a main routine without the file system feature version 0 24 135 Chapter 8 Results of the moving tests 8 1 GPS waypoint following position and navigation data During the processing of the navigation algorithm several errors and bugs occured Dynamic C has an error handler which can be programmed and adjusted for the special needs of the Cool Robots project but that is a great piece of work The original error handler manages how to handle the errors as for example a calculation of arccos 2 These errors have to be excluded If one of these errors occurs dynamic C jumps out of the program at the place where the error occurred without proceeding in the program That made the Cool Rob
99. beginning of packet Destination station Source station And up to 8 intermediate stations Kind of packet packet number and other control information Optional Data with protocol ID Data may have 1 to 256 bytes 16 bits derived from this packet used to check for errors in transmission Single character for end of packet Figure 5 18 Structure of KPC3plus data packets 5 3 Controling the CoolRobot via radio link 92 Thus it is possible to send even big text files without any problems except the slow bandwidth of only 1200Bit s which equals 150Byte s Consequential transmitting a text file of 1kByte would take approximately 6 7 seconds Within this no extra time is included caused by the data of the packet structure and especially not the waiting time for the response from the remote station whether the packet is received correctly or not Which is not very fast and therefore not appropriate for transmitting bigger amounts of data For our use this bandwidth is ok since we got no need for transmitting data exceeding 1kByte For example a set of 5 waypoints see chapter 5 3 3 for the Cool Robot sum up to round about 120 Bytes plus the data caused by the structure the modem appends Thus the transmission of 5 waypoints will take about one second which is absolutely sufficient for our application The receiving station verifies the checksum appended to the data packet and responds to the
100. board The Analog Devices evaluation board eval AD7490cb is used to read analog signals The AD7490 is a 16 channel 12 bit Analog to Digital Converter The first ADC MAX1231 from Maxim was replaced because we had problems with the temperature rating for their evalu ation board Any attempt to adapt the cold temperature rated ADC MAX1230 which is the 5V version of the 3 3V MAX1231 failed and support from Maxim was lacking The second reason for the AD7490 was that it is able to read bipolar signals that are biased at 2 5V The Maxim part could only read 8 bipolar channels because it takes true differential readings from two channels The requirements for a Analog to Digital Converter for our project were not as simple as evidently The first and most important fact was the cold temperature rating of down to 40 C The box of the Cool Robot is insulated and the heat of the motor controllers should keep the temperature always above ambient temperature but this is the maximum rating The main logic is driven by two microcontrollers one Mastercontroller for the navigation and con trol and one Slavecontroller for the power management which is the work of Alex Streeter s master thesis For the navigation and control side the following analog sensors must be read channel signal input range 1 motor current A 2V lt Vow 2V 2 motor current B 2V lt Vow 2V 3 motor current
101. bout 100 m to a basing point where the off bearing is small but the closer the robot gets to the basing point the larger gets the off bear ing because the offset from track is greater compared to the distance to the basing point By making more course corrections the open loop course correction gets more imprecise and the traveled track is getting longer compared to the perfect shortest track between the waypoints Table 8 4 shows the calculated distances for the shortest track the traveled path and the addi tional track traveled for making the course corrections 22 mar 24 mar perfect track 4370 m 2194 m traveled path 5131 m 2258 m additional distance 760m 64m percentage 17 4 2 9 Table 8 4 Overview of distances The perfect track is calculated between the starting point waypointl waypoint2 waypoint3 and waypoint4 For the test on mar 22nd the distance is larger because two loops were per formed The length of the traveled path was calculated with wp4 wp4 PU E J currentdistance i 1 turningdistance i 0 i 0 whereas the turning distance is X turn of f bearing 300 CE 3 I 1000 sec I also calculated the false bearing in the first test out to have a stronger conclusion for the o distance between the basing points The test with a distance of 100 m between the basing points is not acceptable A 17 4 deviation of the track compared to the perfect c
102. ccording to those results I set up the file system in the second flash with the recommend parameter LS size at 1024 Bytes for maximum efficiency I wrote a test program to create a testfile and fill it with virtual navigation data When reading the file back with a small program I wrote 2ndFlashReadLogFile C I came up with a maximum file size of 256 396 Bytes in two independent test runs This is a bit more than estimated because I only used one file to store all the test data and the estimate was calculating with 6 files To get an image of what we are able to record with this amount of memory lets take the actual navigation process and the data recorded or sent to the base while navigating As mentioned in chapter 5 3 3 one complete set of navigation data including the original string received from the GPS unit the waypoint basingpoint both current points and all of the calculated distances 6 1 Storage and retrieval of internal sensor data 106 and bearings sums up to round about 235 characters which equals 235Bytes depending on the actual values carried Considering the available memory of slightly above 253kBytes we are able to store an estimate of 1075 sets of data Assuming an average time between the storage of two data sets of 33 seconds 30 seconds from one navigation cycle to the next plus the time the turn for the course correction takes estimated to 3 seconds in average the total recordable time would multiply to 1075
103. ce number 1 device class byte writeable Device number 2 is the 512k Byte RAM memory the reason why there are only about 128k available for files is that specific areas of this memory are used by the Jackrabbits BIOS 6 1 Storage and retrieval of internal sensor data 105 Dynamic C File Edit Compile Run Inspect Options Window Help 1 s a M x gt V Device number 1 Device detected Silicon Storage Technoloay Device code Aude Sector size 4896 Number of sectors 64 Total bytes 262144 Typical usable bytes 257024 Device offset 262144 Device class byte writable Capacity estimates assuming 6 files maximum ls size num ls available usable Eff X 64 4096 180224 177144 67 128 2048 221184 217080 82 256 18024 241664 236472 96 512 512 251904 245616 93 1024 256 257024 246984 94 2048 128 259584 243368 92 4096 64 260864 232332 88 8192 32 2615804 204300 pra Device number 2 Device detected Manufacturer code Bf Device code x Sector size 128 Number of sectors 1024 Total bytes 131872 Typical usable bytes 118784 Deuice offset 647168 Device class RAM Capacity estimates assuming 6 files maximum Is size num ls available usable Eff X 64 2048 98112 29760 68 128 1624 116592 169836 83 256 512 126832 119184 96 512 256 125952 122568 93 1624 128 128512 121484 92 2048 64 129792 115596 88 ana 39 1365435 1130A 77 Figure 6 3 Screen shot of FS2 sample program showing specifications of the Flash mem Ory A
104. chieve as much matching inserts on the top lid and the chassis itself The exact fitting was done while gluing the top lid together we glued one side of the lid at a time and focused the 13 inserts of the top lid by screwing them to their respective insert on the chassis Doing one side after the other in this manner we assured the best possible fitting The next day when the epoxy on all inserts was cured completely we started with the actual cluing of the top lid We screwed one side of the lid to the chassis and then coated all necessary contact areas with epoxy After this the lid was folded down to the chassis and the other three sides were focused too Since almost all insert holes were focused with screws the lid cured up keeping exactly the right shape Finally a hole was drilled to the middle of the top lid trough which cables for the GPS antenna the radio and the Jackrabbits programming cable can be lead During all the testing the Cool Robot s concept proved itself by being an easy and reliable robot The only real problem we encountered during this time was the connection between gear head and axle The aluminum shaft collars produced some problems with the drive train The aluminum does not provide enough strength in this application there is too much slack ness at the key on the gear heads axle Thus the wheels can turn several degrees without any movement of the motors Furthermore the aluminum of the shaft collars and the rob
105. cks if motor speeds are on 100 and sets them PARAMETER RETURN VALUE Lu nN EY WORDS END DESCRIPTION OKCKCKCKCkCkCk I OK OK ke e x kx void forward full while motor_speed 0 100 amp amp motor_speed 3 100 costate faster forwards motor speed motor speed increment waitfor DelayMs 200 end costate 1 31 r r y r D 2 drive lib 182 end while end function VILI MM B MM LL ML ll LE TT E IP MM MP BM aA TT TT TT TIT TTL TL T TTL TL LTL BeginHeader forward partial void forward partial EndHeader START FUNCTION DESCRIPTION Ck CK Ck Ck Kk Ck CK CI Ck CK C CC Ck I E A Kx KG KG ko ko ko void forward partial lt drive lib gt SYNTAX void forward partial VJ ESCRIPTION checks if motor speeds are on 100 and sets them PARAMETER RETURN VALUE Gl A EY WORDS END DESCRIPTION Fe I Kk Kk kok kok KK void forward_partial while motor_speed 0 60 amp amp motor speed 3 60 costate if motor_speed 1 lt 50 amp amp motor_speed 2 lt 50 faster forwards motor speed motor speed increment end if else if motor_speed 0 gt 70 amp amp motor speed 3 gt 70 slower_forwards motor_speed motor_speed_increment end else if waitfor DelayMs 200 end costate end while end function
106. control signal Data Terminal Equipment e g a personal computer running terminal software Data Terminal Ready Yet another flow control signal 32 bit IEEE floating point Recommended Minimum Specific GPS data structure implemented in the code for latitude and longitude of a position Global System for Mobile communications Interface Control Document defining characteristics of and data for the GPS L1 and L2 Signals in Space SIS LIST OF SYMBOLS xi int I O IRLP ISU lat LF lon NMEA NMEA 0183 PTT RI RS232 RTS RX SCLK SG SPI TTFF TX wp XON XOFF 16 bit signed integer value Input and Output Iridium Radio Link Protocol Individual Subscriber Unit IRIDIUM modem latitude Line Feed same as new line n longitude National Marine Electronics Association Interface Standard that defines specific sentence formats for a 4800 baud serial data bus Push To Talk V 24 Signal Ring Indicate ISU signal that indicates an incoming call Today named EJA232 and is a common interface standard for data communication Reguest To Send Receive signal Serial Clock Internal Clock of Jackrabbit Signal Ground Serial Peripheral Interface three wire Time To First Fix Transmit signal waypoint A standard flow control method Chapter 1 Introduction The Antarctic Plateau a large high altitude mass of ice and snow covering most of Antarc tica and impacts the atmospheric circulat
107. control the brushless dc motors through serial port D The AD7490 is a 16 channel 12 bit analog to digital converter with up to IMSPS Mega Sam ples Per Second and a 12 bit control register The control register is a write only register with the MSB Most Significant Bit transferred first For the data in the control register being transferred on the DIN line at the same time the conversion result is send out on the DOUT line to the Jackrabbit each control register change is valid from the next conversion only As every conversion result is a 16 bit data word it takes 16 serial clock cycles to load the new 12 bit control register data The 12 control bits are followed by 4 zeros but only the first 12 bits are loaded to the control register Figure 3 19 shows the structure of the 12 bit data word loaded to the control register MSB LSB WRITE ADD3 ADDI ADDO PMI pao suapow WEAK TRI RANGE 11 10 9 8 7 6 5 4 3 2 1 0 Bit Figure 3 19 12 bit Control register sectioning Write The Write bit has to be set to 1 to load the following 11 bit to the control register If set to 0 the register remains unchanged SEQ Shadow The SEQ and the Shadow bits select one of the four modes of operation of the sequencer If set to 00 the sequence function is not used and only a conversion on the selected channel is made ADD3 ADD0 The four address bits are used to select a channel for the conversion The four bit word corresponds to the decima
108. create amp logfile LOG FILE NAME I if FSrc amp amp errno printf Logfile d already exists n int LOG FILE NAME printf Delete existing file or apend new data to old file n n DELETE y n n gets buf if toupper buf 0 Y EXIST 7 2 Start up sequence initializing of variables file system and serial ports 123 fdelete LOG FILE NAME FSrc fcreate amp logfile LOG FILE NAME else printf Type some seperator n gets buf buf strlen buf n buf strlen buf N0 FSrc fopen_wr amp logfile LOG FILE NAME fseek slogfile 0 SEEK END fwrite amp logfile buf strlen buf The error checks always works the same way all functions used to perform file operations return specific error codes which are stored in the integer variable FSrc After the execution of a function the return code is interpreted by a if statement If an error occurred while creating the new file respectively writing the separator to the existing file the program will be terminated with exit code 4 If everything was allright the file is closed and from now on available for data storage if FSrc printf Couldn t create open file d errno d n int LOG FILE NAME errno exit 4 fclose amp logfile The last part of the start up
109. culated them from the current point within the range of the last basing point I corrected that and the basing points are in the same distances 8 1 GPS waypoint following position and navigation data 139 The basing points outlined in the circles A B C and D were generated unnecessarily How ever the Cool Robot did not head for them so they had no impact on the traveled path The two strange bends were caused by a wrong bearing calculation The current bearing was calculated to 270 instead of 180 so the robot made a left turn to get on its course again after recognizing to be off course again at the next navigation cycle I corrected that 200 m 1 Figure 8 2 Navigation routine at startup Figure 8 2 shows the startup for the second loop Starting with the position determination at point 1 the robot drives straight ahead without a course correction After the time between navigation cycles tm nav which was set to 15 seconds the robot determines the current position 1 and calculates the first current bearing to 313 At that point the bearing to the first basing point is 48 A calculated off bearing of 48 360 313 95 leads to a right turn In the drive mode wp_follow_full the motors on the right side are set to 90 to process a wide turn After completing the course correction current position 2 for the next navigation cycle is taken Then the robot drives straight forward again at full speed for
110. d if strncmp chk string SCRWPT 6 0 case2 waypoint s recieved str len strlen chk string memcpy in string chk string str len l wp rcvd str2wayp in string amp wayp if wp rcvd 1 no error while storing WPs send_event 1 send number of waypoints succesfully received return 4 end if else if strnomp chk string if strnemp c manual drive_mode stop motor_speed memset in_string Ox hk_stringt6 drive mode 5 motor_speed_in 00 sizeof in_ SCRCMD 6 case3 command recieved MANDM 5 cmd for entering switch to maunal drive mode crement string else if str waypoi nemp chk stri nt following f ng 6 WPFFL ull speed 5 0 cmd for entering drive_mode stop motor_speed memset in_string Ox E motor speed in 00 sizeof in_ switch to wp_follow_full crement else if str waypoi drive_mode Ze stop motor speed motor speed in memset in string 0x00 sizeof in_ nemp chk stri nt following p string ng 6 WPFPT artial speed switch to wp follow partial crement string 5 cmd for entering D 5 radiocomm e lib 215 else if strncemp chk_string 6 GOTST 5 0 cmd for entering got stuck mode drive_mode 3 switch to got_stuck stop motor speed motor speed increment memset in string 0x00 sizeof in string
111. d for event driven status reports the robot should give in repetitive intervals I wrote some basic code for an IRIDIUM based communication including some functions to originate and end a call accept an incoming call as well as an adapted main routine mainprog 2 3x But all this is only a rough frame that must be fitted to the needs of the Cool Robots mission once all general conditions are clear and the IRIDIUM equipment is available for testing 5 2 Radio Communication Due to high cost of the Iridium connection another communication is needed for the testing during the development of the robot During this time a more or less permanent connection is required and a range of several hundred meters is sufficient The cheapest and easiest solution for a short range digital wireless communication is a packet radio connection A packet radio station consists of three basic parts as shown in Figure 5 7 5 2 Radio Communication 82 NI Antenna KPC 3 Plus Transceiver INC c o mputer Terminal Node Controller ermina Figure 5 7 Components needed for packet radio communication e The transceiver with antenna 1 sends and receives radio signals to and from your antenna and 2 passes audio signals back and forth between itself and the TNC e The TNC Terminal Node Controller 1 translates audio signals into digital information and vice versa 2 performs a number of control and information storage functions and 3 communicates
112. d harsh environmental influences are very small in dimension and most important the frequency range is fitted to the the IRIDIUM requirements which means they provide continuous coverage from 1610 1626 5MHz The various Types of antennas of this family only differ slightly in their dimen sions and electrical specifications Figure 5 4 SAF2040 E mobile flat mount antenna Due to the fact that there is no input or control device included with the A3LA it must be attached to a micro controller or computer equipped with an RS232 serial port All commu 5 1 IRIDIUM Communication 72 nication between the ISU and the Data Terminal Equipment DTE i e micro controller takes place over this serial connection Depending on the attached DTE two wiring possibilities are given First a full 9 wire interface incorporating hardware handshaking and flow control or a 3 wire interface where only ground GND receive RX and transmit TX are connected Connecting the A3LA to the Jackrabbit micro controller a 3 wire interface will be sufficient since hardware handshaking and flow control are not essential for us and would complicate the communication routines and especially the wiring of serial port E Since for this kind of serial communication no SPI protocol is used it can take place while all other systems of Cool Robot are running The only disadvantage of the 3 wire interface is that some settings see chapter 5 1 1 2 must be accommodated to this ci
113. dem turned on Set status_modem Reuse FS Reuse File Set status_modem 1 Try to connect to base Connected E Wait for incoming connection Costate modem input Connection lost Costate compute modeminput and enter drivemodes Costate modem output Figure 7 2 Flow chart of mainprogV0 34 The mainprogV0 35 has basically all the same features as mainprogV 0 34 like data record ing in flash memory the three drive modes and full radio communication capability The robot will still be running only if the modem is on but there is no need for an active radio link As soon as the program is compiled the settings for the file system are made and the modem is detected on the robot will switch to waypoint following at full speed and start navigating towards its first waypoint It will try to connect to the base for about one minute and if the connection is successful the navigation data will be send back to the base in addition to the 7 4 Different versions of the main programm 132 storage in flash memory If it can t connect it will go on with its navigation and listen for an incoming connection request As soon as a connection is detected navigation data is sent back and the robot can be controlled as with the mainprogV0 34 If the connection is lost or terminated again CoolRobot will go on with navigating if it was operating in one of the waypoint following drive modes I
114. digitally with your computer e The computer communicates digitally with the TNC so you can 1 view messages received from the transceiver or stored in a mailbox i e PBBS 2 use the computer to send data to and receive data from other stations via the TNC and your transceiver and 3 control the operation of the TNC In our case the transceivers were a set of two Cobra FRS 105 hand held radios which were replaced with ICOM 4088 radios As Terminal Node Controllers two Kantronics KPC3plus packet radio modems are used and as Terminals the Jackrabbit RCM3100 micro controller is used on the robot side and a personal computer with terminal software such as Hyper Terminal can be used on the user side Those components are fairly cheap and permanent connection can be established without any extra expense 5 2 Radio Communication 83 5 2 1 The Kantronics KPC3plus packet radio modem The packet radio modem we are using is a commercial Kantronics unit priced 186 figure 5 8 It is fairly lightweight weighing only 320g and small measuring 133x133x21mm Another positive aspect is the low current just below 30mA at 6 25VDC when the unit is active and the control LEDs are on This power consumption can be cut down to around 15mA at 6 25 VDC by turning off the control LEDs using the command LEDS OFF The modem connected to the PC is powered by a 9V battery and the other modem inside the CoolRobot is supplied by 10VCD from the internal
115. direction in_str write lon_direction to wayp else return i wp list wp count wayp write wayp to wp list wp count tt increment wp count end for return i end str2wayp TT TL TL TL Mg MM P P L T T TL T BeginHeader termStr char termStr char buffer extern char buffer 250 EndHeader int m START FUNCTION DESCRIPTION KK KK KKK KKK KKK KKK KKK KKK KK ck ckck c kck termStr lt radiocomm_e lib gt SYNTAX char termStr char buffer D ESCRIPTION The function simply terminates a string pointed to by buffer with a carriage return Nr Buffer points to the terminated string afterwards A PARAMETER1 Pointer to string up to 255 characters long ETURN VALUE Pointer to the carriage return terminated string EY WORDS carriage return terminate END DESCRIPTION OKCKCKCKCkCKCk I OOK ke e x kx har termStr char buffer D 5 radiocomm e lib 212 int m m 0 while buffer m N0 buffer m buffer m mtt buffer m Nr buffer m 0 return buffer end termStr T TL L LT LL L T TTT BeginHeader clearStr char clearStr char str EndHeader START FUNCTION DESCRIPTION CC CC C Ck Ck CK CI CI CI I SC x A Kk A A AA clearStr radiocomm e lib SYNTAX void clearStr char buffer O ESCRIPTION Function deletes leadin
116. e sentence amp newpos lon degrees amp newpos lon minutes return 1 get coordinate failed if i 4 lon direction newpos gt lon direction sentence if i 5 link quality if sentence 0 return 2 else if strncmp sentence SGPGLL 6 0 parse GLL sentence for i 0 i lt 6 i sentence strchr sentence if sentence NULL nandle short GLL sentences from Garmin receivers if i gt 3 break return 1 D 3 gps lib 192 sentence first character in field pull out data if i 0 latitude if gps parse coordinate sentence amp newpos lat degrees amp newpos lat minutes return 1 get coordinate failed if i 1 lat direction newpos gt lat direction sentence if i 2 longitude if gps_parse_coordinate sentence amp newpos lon degrees amp newpos lon minutes return 1 get coordinate failed if i 3 lon direction newpos gt lon direction sentence if i 5 link quality if sentence A return 2 else if strncmp sentence SGPRMC 6 0 parse RMC sentence for i 0 i lt 11 i sentence strchr sentence if sentence NULL return 1 sentencet first character in field pull out data if i 1 link quality if sentence A return 2
117. e Edit Settings Help Selected Sensors Tablet 60 RR POR Average Table Name Store Every Minutes T107 C Minimum AM16 32 not v Sample StdDev 1 Tablet 2 Table2 Table2 Advanced Outputs all tables Add Table Delete Table Figure 6 6 Screen shot of Short Cut third step select tables There are actually two possibilities to send and receive data via the serial port from within a running program on the CR5000 CR1000 The first one is via a CAN bus system which is to difficult and extensive in code space to implement it on the CoolRobots micro controller in addition to the existing software Another way might be through two commands for input from the CR1000s RS232 serial and input output on the CS I O port SerialInput Dest Max Values Termination Char FilterString The SerialInput instruction is used to measure a serial sensor connected to the datalogger s RS232 port This instruction can be included within every cycle of the measurement program to check for an input character string and store it to a predefined array if something is received The parameters of SerialInput are Dest The Dest parameter is a variable array in which to store the values received from the serial sensor The array should be dimensioned to the size of Max Values 6 2 The Campbell CR5000 and CR1000 dataloggers 112 Max_Values is the maximum number of characters that will be transmitted by the sensor between the filte
118. e last comma is not neccessary but it also wiil not bother the function processing this input If the waypoint string was send and received correctly CoolRobot will answer how much new waypoints it received and stored Alternatively if any error occurred within the waypoint string the robot will respond only with the number of waypoints it received correctly For example if 5 waypoint were sent and there is a problem within the third waypoint the robot will only store the first two correct waypoints and report that it successfully received 2 waypoints kpc3plus HyperTerminal P File Edit View Cal Transfer Help Dis sla fel s KANTRONICS KPC3PMM VERSION 9 0N C COPYRIGHT 2002 2003 BY KANTRONICS INC ALL RIGHTS RESERVED DUPLICATION PROHIBITED WITHOUT PERMISSION OF KANTRONICS cmd MAHONY gt GOEK lt lt C gt gt x CONNECTED to MAHONY 8 0B 0C 0D 0 p A 0B 0C 0D 0 GPS parsing error CRWPT 2 4308 2354N07209 7965W 4309 2874N07211 79034 2 waypoints received GPS parsing error Figure 5 20 Screen shot of Hyperterminal sending waypoints For the testing it might also be important to manually switch between different drive modes back and forth Therefore a set of commands is implemented to enter every of the four imple mented drive modes independent from the robots actual drive mode The commands consist of the header CR plus three characters indicating a command CMD and code of five characters for each dr
119. e robot Older data will be filtered and passed to the datalogger Thus one can reconstruct the behaviour and condition of the robot during the whole journey Goetz deals with the overall control and navigation algorithm based on waypoint following through GPS The robot s main intelligence are two microprocessors which are programmed in Dynamic C a computer language similar to C One is used for the power management which is Alex Streeter s M S thesis The second microcontroller is for communication It com municates with the GPS Receiver to get the GPS data with a Digital Analog Converter to control the 4 brushless dc motors and with an Analog Digital Converter which reads the sen sors such as wheel speeds motor currents and tilt angles So the first task was to write the code for the microcontroller to take the readings from the Analog Digital Converter Getting the GPS position data it calculates basing points in a specified distance from each other on the track between waypoints and corrects its heading by open loop control The Antarctic Plateau consists of over 5 million square kilometers relatively flat terrain The surface of the snow is very hard and has a lot of wind blown sastrugi with a size up to 25 cm which are a challenging task for the control and navigation algorithm Figure 1 3 shows a typical sastrugi field along with a breifcase of height 20 cm Navigation through sastrugi fields may cause brief dislocation of several degr
120. e seq Dn Is used to dial a data or voice call number Syntax is ATDnx x where n is a modifier for the dial instruction and x x represents the number to dial Allowed values for x are 1234567890 ABC The modifier alters the way the A3LA is dialing 5 1 IRIDIUM Communication 75 L redial last number P use Puls dialing T use Tone dialing it doesn t matter whether Puls or Tone dialing is used international dial prefix start a voice call without this a data call is originated gt used to dial a number from the phone book Table 5 1 Modifiers for Dn En Determines whether characters are echoed locally Echoing characters locally should be dis abled on the CoolRobots modem see chapter 5 2 1 2 for explanation n 0 characters are not echoed to the data terminal n 1 characters are echoed to the DTE Table 5 2 Modifiers for En Hn Used to hangup a data or voice call originated with ATD ATA or ATSO n answer commands A zero value for n places the modem on the hook On The online command switches from in call command mode to in call data mode Any value n 0 to n 255 is allowed but does not change the effect of the command S0zn Sets the modems SO register which holds the setting for auto answering to the value n carries Every value higher than 0 enables the auto answering function n 0 disables auto answering It should be a good idea to enable this setting on the CoolRobots A3LA since answering
121. ec return 0 else return 1 unknown sentence type BeginHeader gps_ground_distance float gps ground distance GPSPosition a GPSPosition b fuse DoublePrecision lib EndHeader START FUNCTION DESCRIPTION KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK gps_ground_distance gps lib SYNTAX float gps ground distance GPSPosition a GPSPosition b nN EYWORDS gps UJ ESCRIPTION Calculates ground distance in km between to geographical points Uses spherical earth model PARAMETER1 a first point PARAMETER2 b second point RETURN VALUE distance in kilometers SEE ALSO END DESCRIPTION OKCKCKCKCKCKCkCk kCK Ck kCKCkCkCK Ck kCK Ck kCKCkCkCKCkCkCKCkCkCK Ck kCk k kk k kc k kck ck kok ck K kk kk ke e ke ke x loat gps ground distance GPSPosition a GPSPosition b loat angle pi loat lat a lon a lat b lon b _double dummy00 diss double lat x lat y lon x lon y pi 3 141592654 Fh Hh c Hh lat a a gt lat degrees a gt lat minutes 60 if a gt lat direction S lat a lat a lat a lat a PI 180 lon a a gt lon degrees a gt lon minutes 60 if a gt lon direction E lon a lon a D 3 gps lib 196 lon_a lon_a PI 180 lat b b lat degrees b lat minutes 60 if b gt lat direction S lat b lat b lat b lat b
122. econds the call is terminated n 2 the modem changes to on hook command mode call is terminated n 3 the modem changes to on hook command mode and AT command profile O is reset Table 5 5 Modifiers for amp Dn amp Kn This setting selects which flow control method is uses for the communication between DTE and modem n 0 no flow control is used flow control is disabled n 3 enables RTS CTS Ready To Send Clear To Send hardware flow control n 4 enables XON XOFF software flow control a standard flow controll method to prevent overflow overrun n 5 enables both RTS CTS and XON XOFF flow control Table 5 6 Modifiers for amp Kn Wn This command can be used to store the active settings in one of two available profiles n 0 stores the active configuration as profileO and n 1 stores the active configuration as profilel Table 5 7 Modifiers for amp Wn CBST Select the bearer service type for mobile originated calls This setting determines which mod ulation protocol is used for the data transmission during a data call The command must be in this form AT CBST lt speed gt lt name gt lt ce gt 5 1 IRIDIUM Communication 78 speed can have the following values 0 Autobauding 1 300 bps V 21 2 1200 bps V 22 4 2400 bps V 22bis 6 4800 bps V 32 7 9600 bps V 32 default 65 300 bps V 110 66 1200 bps V 110 68 2400 bps V 110 70 4800 bps V 110 71 9600 bps V 110 lt name gt takes the following va
123. ect again The point is the modem on the robot will not realize that the connection is lost without failing to send a data packet or the notification from the remote station that the connection is terminated Therefore it will be confused if there is another incoming connection request from the station it is supposed to be connected to Clearing this confusion always takes some time which can be easily avoided by terminating the connection before a restart of the program 5 3 Controling the CoolRobot via radio link 95 5 3 2 Manual drive mode The use of the manual drive mode is the ability to maneuver CoolRobot over short distances and in places where high mobility is needed for example to drive it out of a building or vehicle to an open area where it is able to navigate on its own Furthermore the ability to drive the robot manually like a remote controlled car is essential during testing since it is the only way to make the robot drive over certain obstacles forth and back and repeat this over and over again or just drive straight line to collect current measurements and so on The intention was to make the robot driveable like a small remote controlled car Unfortunately there is no actual remote control with a steering wheel and a throttle but with a notebook attached to the radio modem and radio it is very similar In the first place Goetz wrote a function to control the robot while it is connected to a computer via the programming cable
124. ees in bearing But for the distance from waypoint to waypoint being about 50 kilometers the distance off from its calculated track can be 20 meters or more without incurring major path deviations Specific problems the sastrugis can cause are high centering and tipping over To avoid high centering the wheel speed sensors and the motor currents are set up to detect wheels that are not in contact with the snow The bottom of the robot is plated with polyethylene which has a very slick surface to make a slide to one side easier enabling a control routine to get unstuck see chapter 4 5 3 Dr James Lever took a picture on Ross Ice Shelf while travelling on the traverse from McMurdo station to the Leverett Glacier and Polar Plateau in december 2004 The picture shows the wind blown sastrugi features on Ross Ice Shelf with a notebook 20 cm large Figure 1 3 Sastrugie features in Antarctica with 8 inch notebook for scaling To avoid the robot from tipping over the 3 axis tilt sensor sends an interrupt to the control algorithm see chapter 3 3 6 This thesis starts with the assembling process for Cool Robot We hope to give a summary of good practices for handling the honeycomb and some useful hints for refining next Cool Robot design Chapter 3 deals with the navigation of Cool Robot and provides all the necessary information to understand the basic mode of operation of the gps receiver as well as the main navigation program of Cool Robot
125. elocity D output 8 asin scale tilt ReadAD READ AIN08 400 motor tilt pitch output 9 asin scale tilt ReadAD READ AINO9 400 motor tilt roll printf currents A B C D are f n output 0 printf velocities A B C D are d d d n int output 4 int output 5 int output 6 end read sensors BeginHeader sensor range int sensor range fuse drive lib extern float output 15 extern int wp start EndHeader START FUNCTION DESCRIPTION KKEKKKKKKKKKKKKKKKKKKK x x KG kk ko ko void sensor range lt analogin lib gt SYNTAX void sensor range DESCRIPTION will check the sensors readings and look if they exceed the limit and change drive mode Jj ETURN VALUE Lu nN EY WORDS END DESCRIPTION OKCKCKCKCkCKCk kok k Ck kCk Ck k ck k kc k k I OK OK ke e x kx int sensor range if abs output 8 gt tilt lim abs output 9 gt tilt lim stop motor speed motor speed increment D 1 analogin lib 171 backwards_tilt while 1 costate waitfor DelayMs 4000 turn_right motor_speed angle waitfor DelayMs 18000 end costate costate waitfor DelayMs 22000 stop motor speed motor speed increment if driveN mode 1 Forward full end if else Forward partial end if wp start 0 return 0 end costate end while else retur
126. f the connection is lost in manual drive mode it will reside in this mode but stop the motors just to prevent uncontrolled driving Another slightly different version is called mainprogV0 24 it is basically exact the same main routine as in mainprogV0 34 only the ability to store data on the internal flash memory is missing It is designed for the use with the smaller Jackrabbit which only has 256kBytes of flash memory not enough to implement a sufficient file system to store serious amounts of test data All other function are the same with the tiny difference that no data from the logfile will be sent back on a data request since there is no actual logfile existent The answer is always no data found To run this variant of the main routine a small change in the code of NAVIGATE LIB must be performed Lines where the navigation data is written to the logfile lines 167 170 must be commented out using either at the beginning of every line or enclose the four lines in 7 4 Different versions of the main programm 133 Reuse FS Reuse File Set status_modem Try to connect to base Costate modem input Connected and enter to base drivemodes Check Modem on Wait until modem turned on Costate Set status_modem and enter drivemodes Costate modem output Figure 7 3 Flow chart of mainprogV0 35 All three versions of the software have
127. f the essential return and error codes the IRIDIUM modem may produce Numeric D5 08 JVau RVVWU OU RB A RB Oo oo Ek n 69 as textual as textual as textual as textual Textual z O K Ei CONNECT RING NO CARRIER ERROR CONNECT 1200 NO DIALTONE BUSY NO ANSWER CONNECT 0600 CONNECT 2400 CONNECT 4800 CONNECT 9600 CARRIER 1200 75 CARRIER 4800 CARRIER 7200 CARRIER 9600 COMPRESSION V 42 bis COMPRESSION NONE DR V42B NONE DR V42B TD DR V42B RD DR V42B Description Acknowledges execution of command voice call connection has been established Data call connection has been established Incoming data or voice call received unsolicited Data or voice call connection terminated Command not accepted Data call connection established at 1200 bps No dial tone detected Busy signal detected Data or voice call connection completion timeout Data call connection established at 600 bps Data call connection established at 2400 bps Data call connection established at 4800 bps Data call connection established at 9600 bps Data rate detected at V 23 backward channel Data rate detected at 4800 bps Data rate detected at 7200 bps Data rate detected at 9600 bps Data call connected with V 42bis compression enabled Data call connected with no data compression Data call connected with no data compression Data call
128. fer 0x00 sizeof buffer printf sWMn in string end if end costate As soon as the cofunction returns it is verified that there is actually something received and buffer is not empty If there is a non zero string received it will be copied to the variable in string and then terminated with a carriage return character and a zero character using the helper function termStr char After this buffer is flushed and the received string is printed to the Studio window if the micro controller is connected to a PC and the DynamicC compiler At the moment almost all important data is printed to the Studio window just to be able to keep track of what is going on with the program if desired 7 3 2 The main control block The costate for the main control block starts with the function processModemStr char This function analyzes the character array in string which contains the a string received from the modem if there was one received The first action is a check if there is actually a string stored in in string if not the function returns immediately the second action is cleaning the string of leading line feeds and cmd prompts using the helper function clearString char The function detects if the modem is on a connection is established or lost and sets the variables status modem to the equivalent value see Table 7 1 Further more it processes incoming commands like switching drive modes status and data requests or
129. ff that feature At the moment I have written a routine that tries to drive the robot backwards off that obstacle and tries to turn one side of the wheel forwards full speed and the other side backwards 67 Chapter 5 Communication of CoolRobot According to the overall concept of the Cool Robot it should basically be able to travel autonomously along a predefined track on the Antarctic plateau The track will be defined through an arbitrary number of waypoints that consist of GPS coordinates Those can be im plemented in the control algorithm of the robot before it starts its journey So why communication between robot and base There are a number of different reasons for a communication system The first and most important is the ability to alter the course of the robot once it is started At some point it might be essential to have the opportunity to stop the mission and make the robot return to its base immediately In other cases one may want to add points to the route to take extra measurements or just alter existing waypoints anticipating possible problems on the planned route Another argument is the fact that the robot might get into some critical situation Although the terrain on the arctic plateau is supposed to be quite even it is possible to get stuck on one of the Sastrugi features Some testing on hard snow with features like those on the Antarctic Plateau showed that there is a possibility to get stuck if the robot runs l
130. first run is indicated with a and the second with b The distance two the first waypoint varies and 8 1 GPS waypoint following position and navigation data 138 depends on the starting point The distances between the other waypoints and the bearings are given in Table 8 2 distance bearing wpl wp2 586m 124 6 wp2 wp3 642m 210 0 wp3 wp4 522m 309 6 Table 8 2 Distances and bearings for the waypoints lake mascoma bridge The distances between the basing points is calculated by the distance between two waypoints The desired distance between the basing points was about 100 m and the real distance is calculated by wp i wp i 1 bp i bp i 1 MORIE integer 100 m for waypoint and waypoint2 it is LLLA 586 586 bp i bp i 1 uL m 172m integer 535577 5 That guarantees the last basing point will coincide with the waypoint In this test I tried to generate each basing point from the current point while within the range to a waypoint or a basing point One can see that the basing points are perfectly positioned if the robot is on the track between the waypoints but if he is off from the track the next basing point will be off the track the same distance So for the next test I generated the basing points on the track between the two waypoints In this first test the distances between the basing points were also not the same because I cal
131. for example This calculation makes sure the last basing point is the waypoint default 1 0 drive_mode An integer that holds number of the actual drive mode and sets the drive mode entered when CoolRobot is started In mainprogV0 34 it is set to 5 at startup which equals manual drive mode Accepted values are 1 2 3 and 5 EINBUFSIZE Sets the size of serial port E s input buffer The value must be 2 1 and is defaulted to 51 1bytes EOUTBUFSIZE Sets the size of serial port E s output buffer The value must be 2 1 and is defaulted to 51 1bytes FS USE PROGRAM FLASH Defined on beginning of the main program This parameter for the file system determines how A 1 Overview of parameters and variables 152 much kilobyte of program flash memory are set aside for the file system It is set to 16 at the moment but it is not essential if the second flash memory is used because when using the second flash for the file system no program flash is needed GPS_inv_limit main_prog Integer that sets the number of cycles to retry for a valid GPS string before returning to manual drive mode an stop For the algorithm performing one GPS data reading every second it is also the time in seconds to retry for a valid data input default 30 LOG_FILE_NAME Sets the file name of the logfile The value must be an unsigned integer 1 to 255 It is set to 1 LX 2 USE which equal 2 since the logic extend LX we are u
132. g line feeds n and cmd strings he string pointed to by buffer ct PARAMETER1 Pointer to string up to 255 characters long RETURN VALUE none N EY WORDS clear line feed string Lr ND DESCRIPTION OKCKCKCKCkCkCk ck kCk Ck kCk Ck k ck k kc k k kc k kck ck kck ck ckck ck k kok ke ke e x kx Q har clearStr char str char dummy 256 memset dummy 0x00 sizeof dummy while 1 if str 0 n strtt memcpy dummy str 1 254 memcpy str dummy sizeof dummy end if else if strnomp str cmd 4 0 str 4 memcpy dummy str 4 250 memcpy str dummy sizeof dummy else return str D 5 radiocomm e lib 213 end while end clearStr L TL TL L TL TL L L T TL L T BeginHeader processModemStr int processModemStr char chk string extern int status modem extern int wp rcvd extern int send event extern int tm count extern char in string 256 EndHeader static const char cmp connected CONNECTED to GOEK static const char cmp modemon DUPLICATION PROHIBITED static const char cmp disconnected DISCONNECTED static const char cmp setbaud PRESS TO SET BAUDRATE static const char cmp modemtest2 EH static const char cmp modemtestl cmd Sie START FUNCTION DESCRIPTION Ck CK Ck Ck
133. g system and to synchronize the four amplifiers The four switches are set up for velocity mode with the parameters to adjust with the poten tiometers The function of the four 14 cycle potentiometers are outlined below Pot 1 This potentiometer adjusts the loop gain in velocity mode The loop gain increases while turning clockwise For the Cool Robot it is turned fully clockwise 4 3 AMC brushless servo amplifier and EAD brushless dc motors 56 Pot 2 This potentiometer adjusts the current limit Both continuous and peak current can be adjusted up to the maximum ratings of 7 5A for the continuous current and 15A for the peak current The peak current limit is always double the continuous limit and at maximum when fully clockwise Pot 3 This potentiometer adjusts the reference gain This means the ratio between input volt age from the DAC and output velocity is increased by turning the potentiometer clockwise Not every amplifier is turned fully clockwise for the Cool Robot because due to production differences or load differences the general reference gain limits are not at the same level Pot 4 This potentiometer adjusts the offset for the input signal and is used to offset any imbalance in the input signal or in the amplifier It is important that DIP switch 4 is in position Off or offset The potentiometers are set to produce a maximum revolution of 5000 rpm with a 3V input voltage from the DAC s To assure that all f
134. gi feature or a very firm accumulation of snow with two or more wheels not in contact with the snow Another reason for the motor current sensors is the very firm energy budget The Cool Robot 3 3 Analog sensors 47 is powered by solar energy which is a very constant and stable energy source when the sun is shining There will never be too much energy and if there is a surplus of power then it is nice to know for the next generation of Cool Robots Logging the motor currents gives a very important and highly interesting information on rolling resistance on the snow in Antarctica and will be useful for further expeditions Both sensors are provided by the AMC brushless servo amplifier on the connector P1 The current monitor output is connected to pin8 and the velocity monitor output is conncted to pin15 The current monitor output is a voltage scaled by the factor two for each ampere cur rent draw 1V 2A A positive voltage tells the user that the dc brushless motor is turning clockwise and a negative voltage counter clockwise The current monitor output is always within a range of 2V lt V lt 2V due to the set current limit of the motors Vvel V 13884 1 5000 rpm Figure 3 23 Velocity monitor out vs motor revolution The velocity monitor output is a periodic voltage with a rising offset for an increasing rev olution The output scales with 1V per 120 Hz Hall frequency At a maximum revo
135. gin lib Goetz Dietrich 2005 version 0 91 no sequencing 0 5V input range sensor high centered new tm hc new time check for high center must be set to 0 in main 0 2xRef ESCRIPTION ACkCkCk ck CkCk ck kCck ck ck ck ck k ck ck kc kck ck k ck ck ck ck ck ck ck ck ck k ck ck k ck ck k k kk HH AX wheel air new wheel that is in the air must be set to 4 in main tilt hc 2 new referenc will set up and read a Analog Devices tilt angle EVAL AD7490BC evaluation kit 12 bit A D converto Connected to serial port B as outlined below AD7490 GND VDD SCLK CS DIN DOUT ReadAD RCM Jackrabbit GND 5V PBO PDO PC4 TXB PC5 RXB read_sensors sensor_range sensor_high_centered D 1 analogin lib 167 END DESCRIPTION OKCKCKCKCKCkCk Ck kCk Ck kCKCk kc KCkCkCK Ck kCKCkCkCKCKCkCKCkCkCK Ck k Ck A I I I I e xe BeginHeader ReadAD float ReadAD char Command int Samples extern int Value extern int Count data one data one comp extern char data 3 extern unsigned long i f u extern float Voltage extern unsigned long data all fclass auto SPI library definitions Power on state define WRITE 0x80 1xxx XXXX XXXX XXXX write to conversion register define XREF2 0x00 xxxx xxxx xxxx xxlx range from 0 V to 2x Vref V define POWER 0x03 xxxx xxll xxxx xxxx no power up delay U ULL TT Channel Selection
136. hapter 7 3 3 If the logfile cannot be opened because it does not exist there is no data or less than 32 bytes to read back the answer will be could not open logfile respectively no data found 5 3 Controling the CoolRobot via radio link 101 kpc3plus HyperTerminal File Edit Yiew Call Transfer Help GPS parsing error GPS parsing error CRDRO GPS parsing error last 32 bytes of logfile rsing error Figure 5 22 Screen shot of Hyperterminal reguesting data from CoolRobot These are all communication related commands and features actually included with the Cool Robots main program For a short summary on the reliability and the test results with Cool Robot and its communication system see chapter 8 4 102 Chapter 6 Data storage Since CoolRobot is designed to act as a multi purpose mobile platform for scientific mea surement instrument in the Antarctic region one of the main issues within the future missions will be to collect and record data of the scientific payload Most of this scientific data will be analog output voltages from various sensors To record this data the robot will be equipped with a Campbell Scientific CR1000 datalogger which just arrived and is now available for first tests EN P BA biis Figure 6 1 Picture of the Campbell Scientific CR1000 datalogger Besides this scientific data produced by the carried payload the robots internal sensors and the control algorithm
137. he CR5000 datalogger called PC9000 to control it via a personal computer furthermore an extensive manual which describes how to handle and program the CR5000 but not one sentence about commands to control it using a micro controller or something equal It is not essential that the datalogger 6 2 The Campbell CR5000 and CR1000 dataloggers 109 can be controlled by the micro controller but it would score a lot of benefits It would achieve the possibility to start stop and run different recording programms on the datalogger during one journey furthermore the communication and data exchange between micro controller and datalogger should be much easier Follow the steps below to create a datalogger program Step 1 Create new file or open existing file 4 New Open Step 2 Scan Interval 9 g Scan Interval 5 S d X Step 3 Minutes Step 4 X Cancel Help k format 3 Figure 6 4 Screen shot of Short Cut first step edit measurement interval According to the datasheet of the CR1000 datalogger and its manual the serial communication is supposed to be much easier in this product generation Furthermore it is much easier to build simple programs for sensor readings since in addition to the CRBasic editor also included with the CR5000 there is a wizard program called Short Cut included with the CR1000s LoggerNet software package CRBasic is a BASIC like programming language used to create programs for the Campbell datal
138. he different motor currents one can tell very pre cisely what the current torque output for each wheel is The overall mean current for all four wheels is 1 66 ampere That would lead in an energy consumption of Earive Tau Usupply 1 66 48 W 79 68 W 8 1 for the propulsion on flat terrain 8 3 Rolling resistance For the 16 inch tires I took some current measurements for all wheels in different conditions The total weight of the Cool Robot at that point was 82 lbs 38 kg The temperature for the hard surface data was 25 F 4 C and the temperature for the high centered data was 70 F 21 C The different values for the test data used to calculate the rolling resistance are outlined below Current mean value while high centered ona box J 1 151 amp Current mean value on hard surface pavement Ia 1 278 amp Torque constant for the motor 10 Kr 0 095 am radius of the 16 inch tires p 7 5 inch M1905 transmission ratio efficiency included tr 100 90 0 9 The surface rolling resistance then is calculated as T tr Irou Le Kr tr FR r r 8 4 Radio Interface and Communication 145 1 278 1 151 amp 0 095 475 90 m NT 0 1905 m E us The internal rolling resistance is Tr t Tuc dg 1 151 amp 0 095 Nm 90 Rb cs ct P pum gt ET r 0 1905 m Finally the total rolling resistance is calculated as the sum of the internal rolling re
139. he preparation for an im plementation of the IRIDIUM connection is also done in this Thesis All different kinds of sensor data e g motor currents etc have to be logged and evaluated Data logging on the main microcontroller itself or an external Datalogger will be aquired ill Statement Hereby I do state that this work has been prepared by myself and with the help which is referred within this thesis Hanover N H 03 29 2005 Goetz Dietrich Toni Zettl Foreword This work is supported by the National Science Foundation grant OPP 0343328 We would like to thank Prof Laura Ray for her great support and help whenever we needed it With her advice she pointed us always in the right direction and led us forward Dr James H Lever for sharing his exceeding knowledge and experience in the field of Antarc tic Science associated with robotics Alex Streeter for his active assistance and his broadly advice for all intents and purposes The Thayer Machine shop for their ear and hints in all mechanical questions The Thayer Instrument room for their supply with all devices and parts needed Thank you for making this exchange a great experience Hanover 03 29 2005 ii CONTENTS iii Contents List of Figures V List of Tables Vili List of Symbols x 1 Introduction 1 2 Assembly process for Cool Robot 8 3 The navigation and monitoring elements 14 Ad GPS Navigati n sei k hof sug bed ted hae healed yeh 17
140. he wheel is stored and this wheel is checked again after a second If the current is still low and the revolutions at a high level the tilt angles are read out and compared to the first reading After 10 readings of a very low current a high speed and almost no difference in the tilt angles the drive mode high centered is called In the case that the current for the selected wheel increases to the next second the algorithm recognizes that and all four wheels are checked again The drive mode high centered is not implemented yet It is very hard to tell the best way how to get back enough propulsion for further movement That has to be a part for the next students The time the robot waits after defining a high centered position is set to 10 seconds but can be adjusted by tm hc 51 Chapter 4 The overall control unit The overall control unit of Cool Robot is one main part of the robot s logic It consist of the Digital Analog Converter TLV5614 four Advanced Motion Controls brushless servo ampli fier AMC BE15A8 H and EAD brushless dc motors EAD DA23gbb m300 The control unit basically consists of the different drive modes for the Cool Robot A drive mode calls the navigation algorithm checks the sensors and listens for manual interrupts incoming through the user interface radio or iridium modem Depending on the drive mode the propulsion has to be assured Each drive mode checks the motor_speeds at frequent intervals and if needed u
141. hes the drive mode to waypoint following it may drive 30 seconds in the wrong direction but recovers that at the first navigation cycle instead of possibly turning to the wrong direction 3 2 Main program for autonomous navigation 28 start point cp 2 b 1st navigation cycle cp 1 3rd navigation cycle cp 2 TE cp 1 2nd navigation cycle Figure 3 12 Startup procedure 2 with Cool Robot pointing south The function to make course corrections is open loop That means there is no feedback during the turning itself This is due to the impreciseness of the bearing information and the lack of a compass see chapter 3 1 But the open loop correction meets the requirements for our project What are 10 m on a whole continent of ice For the course correction I measured the time it takes the robot to make a 360 turn while driving the motors on one side at only 90 speed instead of 100 for waypoint following at full speed and one side at 50 instead of 60 for waypoint following at partial speed That is possible because the motorcontrollers are setup in velocity mode That means they try to keep the motor at the desired speed by drawing more current For example if the initial bearing to the first active waypoint is 230 the function calculates an off bearing of 130 without taking the robot s current heading into account The off bearing range is converted from 0 lt a lt 360 to 180 lt a lt 180 with
142. high tilt or a high centered position are checked once every second Then after the defined navigation cycle time tm nav 30 seconds has elapsed the navigation algorithm is called The robot will now parse its current position correct the course if necessary and will return back to the 4 4 The different drive modes of Cool Robot 61 main loop after that The drive mode wp follow full sets the paramaters for the navigation based on GPS data It defines the distance between two navigation cycles which has to be aligned with the desired precision the available GPS precision and the distances to travel If the robot navigates once every 10 seconds it will make a lot of course corrections and the track will look like a sawtooth If the time between two navigation cycles is larger then 30 seconds for example the algorithm will smooth the track by taking shifts in bearing caused by the terrain into account The drive mode also includes the only obstacle avoidance of the robot high tilt angles The ter rain in the Antarctica is mostly flat and obstacles like mountains or crevasses can be detected on satellite images The waypoints given to the Cool Robot force it to avoid these obstacles The sastrugies sculpted by the wind have to be handled Therefor we have the tilt sensors The slow speed of the robot allows us to stop it back it up and drive around the feature if it would be dangerous to climb it During waypoint following at full
143. hing the radio and modem all the time but not even one packet was sent twice So the software as well as the hardware are performing consistently For further use it might be good idea to supply the radio on the robot by 5V of the internal housekeeping instead of batteries and maybe try to supply the radio modem and radio used by 12VDC from the cars cigarette lighter as far as a car is available just to eliminate the bat tery power problem Although it is still performing without any problems the wiring between radios and modems should be rebuild at some point because the cable is still the one built for test purposes in the very beginning and its simply not the nicest and most reliable design I think especially the capacitor resistor circuitry for the push to talk PTT and transmit TX 8 4 Radio Interface and Communication 148 signal should be moved out of the housing of plug Furthermore there are certainly modifica tion and changes possible for the software especially in the case of a data and status request since both are just implemented as an example of what can be done but there is no real use for the control of the robot 149 Appendix A Functions and library overview backwards_tilt clearStr DispStr faster_forwards forward_full forward_partial getgps high_centered manual_drive navigate processModemStr ReadAD read_sensors SendToDAC sensor_high_centered sensor_range slower_forwards SPI_Binit SPI_
144. housekeeping power supply Figure 5 8 KPC3plus front view As Modem is a short form of Modulator Demodulator this device transforms the digital in put signal it receives via an RS232 serial interface into an analog signal a common FM transceiver can handle The KPC3plus uses the CCITT Comit Consultatif International T l phonique et T l graphique V 23 standard This standard determines parameters for a 1200Bit s 1300 2100Hz FSK full duplex communication The data is transferred between two stations with a baud rate of 1200Bit s in both directions Data can be transferred both direc tions simultaneously but in this standard only one direction can use the 1200Bit s and in the reverse direction the baud rate is just 75Bit s The sense in this is that a package of data is sent from one modem to the other using the fast baud rate the receiving modem is able to re spond with a short acknowledgment or request to resend at 75Bit s while receiving more data at 1200Bit s No matter which station is sending the data package is always transferred using the fast baud rate only the response uses the slower speed The digital data is encoded using FSK Frequency Shift Keying The digital information must be transformed into something a commercial radio can transmit therefore the logical values 0 and 1 are represented by two different frequencies within the hearable range A space or 0 is presented by 2100Hz and 1 mark by 1300Hz This speech
145. idea behind it is to get the robot back to navigating again once it is high centered on a large feature with two or more wheels with not contact to the snow The Cool Robot has a ground clearance of 23 cm which is not large but it could handle all the terrain during the tests on mascoma lake Sastrugi features have one sharp edge with slopes of not larger than 40 If the other side rises slowly that is only a problem if the robot drives parallel to that edge with one side of the wheel at the lower end and one side driving on top of the sastrugi If the feature rises rapidly the robot will simply drive against it like it is an obstacle and will not make any movements although the wheels are turning The currents will not drop and the motor velocities will not go up The way to detect that will be a task for the next students To detect a high centered position is already implemented in one of the interrupts The robot is stuck in a high centered position if it is centered on a high feature with the bottom of the chassis and two or more wheels with no contact to the snow It is not able to drive on The sensors for motor currents motor velocities and tilt angle detect this situation and the drive mode high centered is called to get all four wheels back on the snow This has to happen by designing a method to turn each wheel in a different direction and use the weight of the wheels to force the robot to slide to one side and be able to drive back o
146. ies is arctan with 22 terms so a total of 44 operations can result in about 5 bits error Worst case a Ld G Zur ck 27 p Suchen ie Ordner Ez Adresse D Release v Wechseln zu Ordner x CreateDouble US Desktop e CreateDouble MFC Application MB 3 J Eigene Dateien i 54 Create Double Precision Expressions Constant Create Source Code Line liloeallconstank Constant name Exit dummy00 Sin lat a Sinflat b Cosflat a Cos lat b Cos lon_a lon_b Expression Source code line dummyO0 dpAidd dpMul Sin lat_a Sin lat_b dpMul dpMul Cosflat_a Cosflat_b Cos dps ub lon a lon b dummy00 Sin lat_a Sin lat b Figure 3 17 Expression builder for double 3 2 Main program for autonomous navigation 35 Figure 3 17 shows the different syntax for single float and double precision double The window shows the MFC Application to be started The Expression builder helps to generate source code for the new structure double with the known syntax from calculations with floats The expression as programmed for single floats has to be entered in the expression line The expression builder has no button to create the new source code You have to have the expression line in focus and hit the enter key The translated source code line generated appears in the next line and can be pasted into the desired dynamic C function The original expression is shown after the double backslash a
147. initial distance The distance between two waypoints For the first navigation cycle at startup the initial distance is the distance from the first current position to the first active waypoint The initial distance does not change during navigation until the waypoint is reached and the next waypoint is activated initail bearing The bearing between two waypoints For the first navigation cycle at startup the initial bearing is the bearing from the first current position to the first active waypoint The initial bearing does also not change and is calculated together with the initial distance distance to waypoint basing point current distance The distance between the current position and the mentioned point in km The current distance is the distance between the last two current positions 16 bearing to waypoint basing point current bearing off bearing The bearing on which one would reach the waypoint basing point when traveling on The bearing is measured in true degrees from north counted clockwise The current bearing is calculated between the last two current positions The off bearing is the number of degrees the robot needs to turn to head to the desired position e g waypoint offset from track The offset from track is the smallest distance to a direct connection be tween two waypoints The length of the perpendicular to the track through the current posi tion bearing to wp distance to wp off track
148. ion of the Southern Hemisphere Figure 1 1 shows a satellite photo of the entire continent The Antarctic Plateau is composed of the region high lighted Atlantic Ocean Weddell Sea Pacific Ocean Figure 1 1 Satellite Photo of Antarctica Lever It is of course extremely cold and dry but it is also very high and the atmosphere above the plateau is very calm with low wind speeds at all latitudes That makes the Antarctic Plateau a unique location to study the upper atmosphere at high magnetic latitudes providing a stable environment for sensitive instruments that measure the interaction between the solar wind and the Earth s magnetosphere ionosphere and thermosphere 1 Few Robots have been build to discover the Antarctic Plateau They were very heavy and driven by combustion engines These expeditions need either a high assignment of person nel which is a problem in the harsh weather conditions in Antarctica or a large transportation capacity which is very expensive limited by the small size of the Twin Otter arid transport air craft flying within Antarctica and entail hazards at remote landing and takeoff sites Carnegie Mellon University for example developed NOMAD a 725 kg gasoline powered robot for polar and desert environments with a size of 2 4x2 4x2 4m 2 The much smaller Spirit and Opportunity are Mars Exploration Rovers from NASA JPL Each 2 3x 1 6x 1 5m rover weighs 174 kg and has a top speed of 5 cm s 3
149. is special case I implemented some kind of hot key for the navigation testing 5 3 Controling the CoolRobot via radio link 97 5 3 3 Waypoint following During waypoint following at full or partial speed the movement of the robot cannot be in fluenced since it is navigating on autonomously It is only possible to switch to another drive mode i e from waypoint following at full speed to partial speed to reduce the robots speed or to the manual drive mode to controll Cool Robot completely manual Thus there are no commands to control the robot in general Besides from that the robot will send all important navigation data back to its base if an active radio connection is existent This data is condensed into one fairly long string Every bit of data is divided by the next by an abbreviation of its meaning and separators The complete datastring looks like the following example gps SGPRMC 183137 00 A 4336 5477 N 07207 4734 W 1 0 339 5 260205 257awi4336 600002 N 727 800000 W bp 4336 551742 N 727 555389 W cp 4336 547702 N 727 473400 W dw 0 448103 bw 282 402374 dbp 0 111044 bbp 0 111044 cd 0 022833 cb 354 567535 The meanings of the abbreviations are as follows gps contains the complete string as it was received from the GPS unit aw shows the active waypoint the robot is heading to bp shows the active basing point the robot is heading to cp shows the current position of the robot dw contains the current distance to
150. is transferred into a 12 bit integer 0 4095 Therefor in both cases the full scale input range of either OV V or OV 2 Vier is divided into 4096 steps One step is the LSB which has a value of 1LSB Vret oriLSB 2 Veet depending on the input range With a 2 5 V reference voltage the LSB has a value of 0 00061 V or 0 0012V which is the maximum error from the real analog input The output integer is given Vin 1LSB by code for straight binary output Figure 3 20 Straight binary output is used for single ended unipolar signals but the motor current and the motor velocity output signals are bipolar depending on the sense of direction 3 3 Analog sensors 43 REFix 2 x REF REFix REF ov ov V R1 R2 R3 R4 Figure 3 21 Circuit to bias bipolar signals about Vref As the analog to digital converter cannot handle negative inputs the signals have to be biased about V The negative full scale 2 5V is OV and the positive full scale 2 5V is 5V A general circuit to bias up a bipolar input at about 2 5 volts is given in Figure 3 21 The analog input conditioning circuit we use in our case is presented in Appendix C Figure 3 22 ADC DIN and DOUT with analog input signal The DOUT line of the AD7490 shifts a 16 bit data word to the serial port B The first four bits indicate the information on the channel on which the conversion was requested The next 12 bi
151. ith a RS232 interface and a terminal software like Hilgreaves HyperTerminal which is included in most MS Windows installations is required To connect the KPC3plus to a PC an ordinary serial cable with a male and a female DB 9 connector in combination with the included DB 9 to DB 25 adapter The modem uses an 25 pin serial connector so either the adapter must be used or a custom cable can be built with the following wiring KPC3plus Computer DB 25 DB 9 2 3 TXD 3 2RXD 4 7 RTS 5 8 CTS 7 5 SG 6 6 DSR 8 1 DCD 20 4 DTR Table 5 12 Pinouts RS232 5 2 Radio Communication 86 The connection to the micro controller is little more complicated For the communication with the modem serial port E is destined The Jackrabbit has 6 serial interfaces but only two of them serial port B and C are immediately usable from the evaluation board Serial port A is used for programming and debugging using the DynamicC software and ports D E and F are available but only directly from the micro controller The problem here is the micro con troller s logic uses 3 3V whereas a RS232 interface uses 5V logic Furthermore the Jackrab bit s serial ports construe 3 3V high as logical 1 and OV low as logical 0 RS232 is the other way around low OV are interpreted as 0 and high 5V as 1 Therefore a RS232 driver needed to be installed on the evaluation board The driver of our choice is a 40
152. itself will produce a lot of data too Especially within the robots first mission and during the test runs at Dartmouth and later on in Greenland this sensor data is 6 1 Storage and retrieval of internal sensor data 103 of special interest since the whole behavior of the robot can be reconstructed and analyzed using this data Interesting are for example the currents the motors draw as well as the overall current from the batteries while traveling along differently shaped paths to prove the existing estimates for the power consumption On the other hand a lot of the data used within the navigation algorithm is of big interest for later analysis of the way the robot traveled At the moment it is needed to prove the navigation algorithm is working correct and stable 6 1 Storage and retrieval of internal sensor data The alternative to using a datalogger is the internal flash memory of the micro controller The DynamicC software provides a library which allows to build a file system known as file system mkII or FS2 within the Jackrabbit s first or second flash memory Depending on the micro controller used the second flash may or may not be available The Jackrabbit RCM3110 core module provided with the evaluation board has got one flash memory of 256k Bytes whereas the RCM3100 core module has twice as much flash memory divided into two separate chips Both of the memory sections can be used as code memory and as memory for the file system but
153. ive wp count wp rcvd 0 0 0 wp start 0 0 s send event 0 tm count drive mode dis bp 0 5 motor speed 0 motor speed l1 motor speed 2 motor speed 3 UpdateMotorOutput 0 1 2 3 O10 O6 7 7 str2wayp wp string amp test point memset buffer 0x00 sizeof buffer memset in string 0x00 sizeof in string Another important part is the handling of the waypoints for the navigation algorithm The waypoints for the CoolRobot consist of GPS coordinates in the structure GPSPosition which is defined in GPS LIB To store a bunch of waypoints for a complete trip there is an array of GPSPosition structures called wp list and it can hold up to 100 waypoints The func tion str2wayp char GPSPosition is a helper function to translate a character string of a certain shape see section 5 3 4 into waypoints of type GPSPosition and stores them into the wp list The stest point GPSPosition is only some used to temporarily store the waypoint data before it is written to the wp list To keep track of the number of waypoints stored and which waypoint the robot is actually heading to two integer variables are used The first wp count holds the total number of waypoints stored within wp list and the second one wp active indicates the waypoint actually heading to It is important to know that wp active starts counting from 0 So number 0 is the first way point number 1 is the second and
154. ive mode The full command sequence for each drive mode is show in the following table SCRCMDMANDM to enter the manual drive mode CRCMDWPFFL to switch to waypoint following at full speed CRCMDWPFPT to switch to waypoint following at partial speed 60 CRCMDGOTST to switch to the special drive mode when the robot got stuck Table 5 15 Overview of commands to enter switch drive modes 5 3 Controling the CoolRobot via radio link 100 The last two commands for a status request and a data request are already implemented in the communication code but not 100 functional at the moment Both of them cause an answer from the robot but act more as an example for further use then as real fully functional features of the communication To originate a status request the command string CRSRQ must be send to the robot and it will answer this request with a string containing only the number of the actual drive mode it reside in plus the actual set motor speeds kpc3plus HyperTerminal File Edit View Call Transfer Help GPS parsing error GPS parsing error CRSRQ GPS parsing error DrMode 1 MotSpeedA 0B 0C 0D 0 Figure 5 21 Screen shot of Hyperterminal requesting CoolRobots status A data request performed by sending SCRDRQ is a little bit more functional since on a data request the controller will try to open the logfile and read back the last 32bytes to send them back to the user described in detail in c
155. ive value corresponds to a left turn and a positive value to a right turn to correct the course 3 2 Main program for autonomous navigation 34 3 2 3 Double precision floating point in dynamic C Since the best way to tell the robot s heading is to take the bearing between the last two positions while navigating the single precision floating point is not precise enough for the navigation algorithm The distance can only be calculated exactly with the angle between two points on earth measured from geocenter see chapter 3 2 1 Dynamic C does not provide a structure double Robert Richter wrote a double precision library on his own We purchased it from him The package included the dynamic C library his C code a readme file an ex ample file and an expression builder This chapter presents the different functions used for the navigation and the different commands especially the syntax The double precision library creates a data type called double which is internally defined as structurechar Bytes 8 double The accuracy depends on the functions used Add subtract multiply divide and square root are all accurate down to the last bit Add subtract multiply and divide all use 8 bits for rounding with 1 guard bit and 7 sticky bits Square root only has 5 sticky bits The transandentals use C code and each term in the series is rounded so the multiplication and addition can result in two bit error each round The largest ser
156. julodAem S P E o 8 Q Q 56 S Oo 3 E E amp w S Q Figure B 1 basing points current points 1 current points 2 x uw o o amp Figure B 2 Waypoint following test with basingpoints on waypoints 162 Appendix C Schematics overview 163 poA TH COM nyo B3E0Z TXO v nox lt x AJEOZIXAV COM ONId33M35NOH Ajddng Jawod 2nd order Butterworth Filter for the 2 axis tilt sensor Figure C 1 164 pogl zr TLC2272 R8 BL Ete Bminus1 4 ols C7 aua 1k pa m aLbpr gt gt 5 now Lor e 5 rH e o a HI o F E O o E 5 E 3 1 J3 2 1A J3 1 1A Bias J2 2 Bias Figure C 2 Conditioning circuit for the analog motor velocitiy and motor current inputs 165 0 van WO AGT Jd Jvu XU UID oly MEZ nia PlETDIL i ili ae am YJTIOMLNOJ 4OLOW OBILO IAN Xt STIDHLINDO HOLON M MEZ E m Dr am U 5 PINOJ Jo p nasce Japeay uid zxc e EIA apeu aJe suoiaauuo re YaTIOMINOD HOLON a PILIDUL je E a am 8 RIND WIN 3TIOSLNOJ 4OLOW Xf PIULOJ WIN u 9 vdyal zy wep ty Schematic of DAC connections Figure C 3 166 Appendix D Source codes D 1 analogin lib Beginheader ifndef __analogin_LIB define __analogin_LIB Endheader START LIBRARY DI analo
157. k ckCk ck kCck ck k NK A k ck ck k ck ck ck kk ck k ck ck k ck ck ck k ck ck kk ck k k kk kk wp follow partial lt drive lib gt SYNTAX nN EYWORDS tJ ESCRIPTION PARAMETER PARAMETER2 RETURN VALUE Gl SEE ALSO END DESCRIPTION HK kCK Ck kCKCkCkCKCkCkCK Ck kCKCkCkCKCkCkCKCkCkCK Ck kc k k kk k kc k kck ck kk k kk kck IK I void wp follow partial costate waitfor DelayMs 2000 getgps in stri forward partial read sensors end costate costate waitfor DelayMs tm nav 1000 navigate in stri D 2 drive lib 187 end costate end wp_follow_partial U LL TT BeginHeader high centered int high centered char in string extern int drive mode EndHeader START FUNCTION DESCRIPTION CKCkCk ck kCk ck kCckck k ck ck k ck ck k ck ck ck k ck ck k ck ck k ck ck ck k ck ck kk ck k k kk kk high centered char in string lt drive lib gt SYNTAX KEYWORDS DESCRIPTION drive mode called while high centered with motor speeds 0 has to be tested PARAMETERI RETURN VALUE Gl SEE ALSO END DESCRIPTION Te kCK Ck kCKCk kc K Ck kCK Ck kCKCkCkCKCkCk CK Ck kCK Ck I kc k kk kck ck k kk ckok I I I int high centered char in string int stk while 1 stk 0 if strncmp in string exit 4 0 cmd for e
158. ke a reading on the selected channels It will take the average of the Specified number of readings and convert the value to whatever the user wants by scale factors PARAMETER address of command bytes must be 3 bytes PARAMETER2 int number of readings to average RETURN VALUE float volts needs to be scaled by scale factor KEY WORDS END DESCRIPTION OKCKCKCKCkCkCk ck kCk Ck kCk Ck k ck k kck k kck kck ck kck ck ckok ck ckok X ke ke ke e x kx void read sensors D 1 analogin lib 170 mnt sees ain tilt_lim 45 Scale motor 5 4096 0 2 2A 1V and 2 5 V reference Scale tilt 5 4096 0 Scale velocity 5 4096 0 120 60 2 1V 120Hz Hall frequency SPI Binit BitWrPortI PDDR amp PDDRShadow 1 0 PDO 1 BitWrPortI PDDDR amp PDDDRShadow 1 0 PDO output output 0 scale motor ReadAD READ AINOO 400 motor current A output 1 scale motor ReadAD READ AIN01 400 motor current B output 2 scale motor ReadAD READ AINO2 400 motor current C output 3 scale motor ReadAD READ AINO3 400 motor current D output 4 scale velocity ReadAD READ AIN04 400 motor velocity A output 5 scale velocity ReadAD READ AIN05 400 motor velocity B output 6 scale velocity ReadAD READ AIN06 400 motor velocity C output 7 scale velocity ReadAD READ AINO7 400 motor v
159. kk Ck kk Ck Sk Ck C C Ck I E x x KG k amp ko ko ko processModemStr radiocomm e lib SYNTAX int processModemStr char chk string O ESCRIPTION PARAMETER1 Pointer to string up to 255 characters long I RETURN VALUE Integer value 0 1 or 2 for status of the modem nN EY WORDS END DESCRIPTION OKCKCKCKCkCkCk ck I k kck ck Koko kok kok kok sk ke e x kx int processModemStr char chk string char in string 2560 int str len int k GPSPosition wayp clearStr chk string deletes leading n and cmd from the input string if strlen chk string 0 return 0 detects if a connection is established if strncmp chk string cmp connected 15 0 status_modem 2 printf connected n return 2 D 5 radiocomm_e lib 214 detect if the modem is on else if strncmp chk string cmp modemon 10 0 strncmp chk string cmp modemtest1 5 0 strnemp chk_string cmp_modemtest2 3 0 status_modem 1 tm_count 0 printf modem on n return 1 end else if detects a disconnection else if strncmp chk string cmp disconnected 15 0 printf Nn DiScOnNeCtEd n while motor_speed 0 0 motor_speed 3 0 motor speed 1 0 motor_speed 2 0 stop motor speed motor speed increment end while drive mode 5 status modem 1 return 1 else if status modem 2 no modem cm
160. l cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl aw cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl 4 KRRAAA 4337 702 337 7072 337 7158 337 7247 337 7299 337 7342 337 7418 337 7506 337 7608 337 7726 337 7713 337 7735 337 7906 337 7969 337 8301 4338 1 337 8301 337 8498 337 8579 4337 866 337 8719 337 8853 337 8923 337 9044 4337 915 337 9227 337 9333 337 9444 337 9546 4337 962 337 9706 337 9801 337 9881 338 0006 4338 011 338 0221 338 0338 4338 045 4338 053 338 0622 338 0724 338 0817 338 0917 338 1007 338 1056 4337 92 4338 099 338 0934 338 0878 338 0826 338 0758 4338 069 338 0608 338 0565 338 0527 338 0454 338 0414 338 0356 338 0288 338 0246 4338 018 338 0133 338 0093 338 0033 337 9974 4337 99 337 9866 337 9815 337 9767 337 9686 337 9599 337 9529 337 9493 337 9434 337 9349 337 9267 4337 62 337 9048 337 8894 337 8768 337 8636 4337 85 337 8373 337 8291 337 8186 337 8081 337 8006 337 7918 337 7804 4337 71 ZZ ZZZZZZZZZZZZZZ Z ZZ ZZ Z ZZ ZZ ZZ ZZ ZZ ZZZZZZ ZZZZZ ZZZZZZZZZ ZZ ZZ ZZ ZZZZZZZ Z ZZZ Z ZZ ZZZZZZ ZZ ZZ ZZ ZZ 7209 181 7209 195 7209 209 7209 221 7209 235 7209 25 7209 266 7209 277 7209 289 7209 299 7209 321 7209 347 7209 335 7209 323 7209 352 7209 12 7209 352 7209 36 7209 337 7209 32
161. l number of the channel 1 16 PM1 PMO These two bits select the power mode for the ADC In normal operation mode 3 3 Analog sensors 42 they are set to 11 The ADC runs fully powered and allows the fastest conversion rate Weak T RI Selects the state of DOUT after the conversion For SPI interface this bit is set to 0 and DOUT will return to three state at the end of the conversion Range The Range bit selects between two analog input ranges 0 lt Vin lt Vreg if set to 1 or 0 Vin 2 Vreg if set to 0 If the input range of up to 2 V is selected the digital supply voltage must be 5 V Coding Selects the output format for the 12 bit conversion result If set to 1 the format will be straight binary and if set to 0 the result will be returned in twos complement straight binary output twos complement 111 111 011 110 011 111 Do 111 110 4 z 3 Q 000 001 111 000 000 000 qb e e e e s 111 111 011 111 1 LSB Vpep 4096 a 3 1 d 1LSB 2 x Vggp 4096 d 100 010 i ner 000 010 100 001 000 001 100 000 g 000 000 F ov 1LSB VREF 1 LSB Vref 1 LSB VREF 1 LSB ANALOG INPUT Vref 1 LSB ANALOG INPUT VREF IS EITHER REFin OR 2 x REFIN Figure 3 20 Straight binary vs twos complement output format These two different output formats have a different transfer characteristic for the output value only An analog voltage on one of the 16 channels
162. l try to get a connection for about one minute and after that listen for incoming connections If a connection to the remote host is detected the robot will go on with the waypoint following but it will furthermore send back its navigation data after every successful run through the navigation algorithm As soon as a connection is established the robot can of course be controlled like in the first program version The only difference is if the connection is lost again the robot will go on with the waypoint following instead of stopping and waiting to reconnect again Thus using one of the mentioned main routines the robot will always try to establish a connection as soon as it realizes the radio modem is on If the attempt is not successful it will listen for incoming connection requests and autonomously recognize if a connection is established or maybe lost again The operator can easily establish and terminate the radio connection as described in chapter 5 2 1 2 The robot will never terminate an existing radio connection since there is simply no need for this feature A connection can only be terminated by the operator if a need occurs For example if one test run is finished and another program should be compiled to the micro controller or if the there is a need for recompiling the program an existing radio connection should be terminated by typing Ctrl c and d CR see chapter 5 2 1 2 This may avoid some hassle while trying to conn
163. le all the time During the austral summer in Antarctica we have almost 18 hours of sunshine but blizzards are possible And if the energy does not allow a movement 4 5 Perspective on further drive modes 65 at all the energy consumption has to be reduced to a minimum to recharge the batteries with the available sun power The robot should be still able to read the sensors such as wind speed to turn into the direction of the wind and should still have a connection to the user for a status request for example A possible configuration could be the routine in Figure 4 8 4 5 2 Stationary data aquisition read the following sensors tilt sensors wind speed sensor ground clearance t sensor_range interrupt new drive mode payload scientific data recording finished new drive mode no modem listen input send status Figure 4 9 Drive mode stationary get data The parameters for the scientific payload have not been specified yet But as measurements have to be taken stationary the robot changes into a drive mode which is similar to charge_ cycle except that some energy is used for the payload and that most of the bandwidth is reserved for transmitting scientific data A possible routine is pointed out in Figure 4 9 4 5 Perspective on further drive modes 66 4 5 3 High centered This drive mode is possibly the hardest to predict The
164. lt lt lt 20 GPRMC messages i a so alae ood KA ee ond d zhe dn 2 Sample structure GPSPosition current pos lt lt 24 Sample using structure double lt lt lt lt 0 36 Analog input channels usos od A Soe Se GS SS a See eS a 37 ADC DAC Don CABIN ae eee qe ie rope Z ato ree cir od Red s 38 EVAL AD7490CB power supplies lees 39 Switch and link options on EVAL AD7490CB 39 Sensor range handling functions lt lt lt 49 Serial port connections and functions for RCM 51 Control and drive mode overview lle 53 Modifiers tor Dis iiome eei a ea Boek ge Me See 8 CO IRE a ee 75 Modifiers for Ens anaedai ue Sed 4 al oad a Ae a Gb he e LR 75 M dif rs TOR Zn Gea aria te hg noct ee cn t ran hE es vys sak ak ni yn 76 Modifiers TOL BOC a sete atts lela aes Ge e Reo ege tee be iden 76 Modifiers Tor Bois e sup e UE e REC Sg SOM Save bh ue ane eB Powe 77 NICOLAS FOE CIS aoo air tate Gr Boe qr nete Let epe Ope Line haved tol alr ig 77 Modifiers for amp Wn z 24 4 64 4 Pag LX EX X4 deky ode Dw ded 77 Possible values for CBST command 78 Example originating a data call 2 ee ee ee 79 Example incoming data call aoaaa ee ee eee 79 Overview of AT command result codes lt lt 80 PIOUS RS232 7 5 3 eO Seale Sh ee Eee ea ee sa 85 Control keys for manual driving lt lt 44 e 95 LI
165. lue 0 data circuit asynchronous lt ce gt can only take the following value 1 non transparent Table 5 8 Possible values for CBST command As mentioned earlier some settings must be adjusted if a 3 wire interface is used to connect the A3LA with the DTE When operating with a 3 wire connection the following limitations apply AT amp Dn must be set to AT amp DO to ignore the DTR input from the data terminal as it will not be present as an input from the micro controller AT amp Kn must be set to AT amp KO for no flow control or AT amp KA for XON XOFF software flow control as RTS Request To Send and CTS Clear To Send hardware flow control signals will not be present AT amp Cn setting will have no affect as DCD Data Carrier Detect output to the data terminal will not be present AT amp Sn setting will have no affect as DSR Data Set Ready output to the DTE will not be present RI Ring Indicate output to the DTE will not be present 5 1 IRIDIUM Communication 79 The following will describe an example for a communication between the A3LA IRIDIUM modem and a personal computer In this case data call is established data will be transmitted and the call is terminated by side that started the call AT CBST 4 0 1 OK ATD 1603123456 CONNECT 9600 OK ATHO OK asynchronous communication at 2400Bit s it is sufficient to set this once and maybe save the profile using the Wn command acknowledg
166. luminum parts were sandblasted and cleaned before their use As adhesive a two part epoxy containing aluminum dust is used It provides high strength and the ability to fill the spaces within the honey comb The best choice to keep the folded body in place for as long as the two part epoxy needs to cure up was a welding table since it provided the best possibilities to position the chassis using brackets on each side of the chassis One rectangular corner was aligned with brackets to start the gluing in this corner All contact areas at the edges as well as the milled inside of the edges to bend up where covered with a thin layer of the epoxy All four sides were folded up to right angle and the the remaining two sides were fixed by two more brackets The result is shown in right half of figure 2 1 After aligning the chassis correctly the angle aluminum was glued to the insides of all four corners 10 Figure 2 3 Chassis without and with partition wall The next step was adding two partition walls to the corners of the chassis where the motors are located Since the motors are screwed to the chassis box itself and the partition walls we also drilled the holes for this connection before gluing the walls to the box That was not an ideal solution since there is no guarantee for a correct alignment of the motors Thus on further generations of CoolRobots the holes in the partition walls and the chassis box should be drilled after adding the mo
167. lution of 5000rpm and a number of four poles the maximum velocity monitor output voltage is 5000rpm Vier LL 120H z 60sec 2 1V 1 388V 3 15 3 3 5 Function to process the sensor data It is one part to adjust the range for an analog signal to build the conditioning circuits and make the correct connections But reading out the analog to digital converters output is an other This section describes the data processing from the 12 bit integer value to the corre 3 3 Analog sensors 48 sponding output voltage or current The target is to have an output value which is comparable to a multimeter Each signal has an input range from OV to 5V because each analog sensor is connected to the conditioning board But the different functions of the sensors have to be scaled differently to get the desired output The analog sensor readings are programmed in the function read_sensors in the analo gin lib The 16 output channels are read with the function ReadAD The 12 bit return value is an integer between 0 and 4095 Each integer corresponds to a voltage or current By mul tiplying with a scale factor each output can be adjusted separately Each scale factor has to B convert the integer to the chosen input range for the ADC of 5V by voltage output i oc Then each scale factor for the analog sensor s output has to be multiplied For the motor cur rent that is 2 because the output is 1V for 2amp motor curren
168. m2 returns Numl Num2 double dpNeg double Num Changes the sign of a number 3 2 Main program for autonomous navigation 36 double dpMul double Num1 double Num2 Multiplies and rounds Numl x Num2 double dpDiv double Num1 double Num2 Returns Num1 Num2 double dpSqrt double Num Returns the square root double dpSine double Angle Sine of angle in radians _double dpCosine double Angle Cosine of angle in radians double dpArctan double Angle Arc tangent in radians Let me just give a small example of using the structure double main _ double a b c d e float print e dpMul dpAdd a b dpAdd c d e a b c d print dpDouble2Float e printf result of the _double calculation is f print Table 3 4 Sample using structure _double This example ought to show the use of the double precision structure which is not supported by dynamic C and is not known to dynamic C as a data type such as float or integer Variables of _double can be defined and used for calculations with the listed and in the doublepre cision lib library written functions If the user wants to display a number on the screen or transmit a number to a function not listed in the doubleprecision library he has to convert the number to a data type known to dynamic C chapter 3 4 3 3 Analog sensors 37 3 3 Analog sensors 3 3 1 Power and signal supplies and setup for the ADC evaluation
169. me carry on a dialog with the operator via a keyboard interface Each separate task voluntarily surrenders its compute time when it does not need to perform any more immediate activity They following sections will introduce the reader to the status quo of the CoolRobot main pro gram mainprogV0 34 and the distinctions to other versions modified to fit different testing requirements The features of this program are fully implemented radio communication data recording capability within the flash memory and three fully functional drive modes available 7 1 Definitions libraries and variable declarations To keep the program concise and straightforward almost all of the functions Goetz and I wrote for the control program are grouped together in libraries according to their field of use Furthermore some of the features like the filesystem used within the program are also 7 1 Definitions libraries and variable declarations 117 provided in libraries with the DynamicC software Those libraries must be included with the program at the very beginning using the use instruction and some global parameters must be defined using define memmap xmem define FS2 USE PROGRAM FLASH 16 define LX 2 USE fs get flash lx define MY LS SHIFT 9 define LOG FILE NAME 1 LX 2 USE define SPI CLK DIVISOR 10 define EINBUFSIZE 511 define EOUTBUFSIZE 511 define CINBUFSIZE 255 define COUTBUFSIZE 255
170. ment from modem dial international American number 603 123 456 answer from modem connection to remote host is established baudrate between DTE and modem is 9600Bit s now the data transfer takes place every data passed to the modem will be sent to the remote modem escape seguence forces the modem to in call command mode acknowledgment places modem on the hook terminates call acknowledgment Table 5 9 Example originating a data call The next example is guiet similar to the one above only this time the data call is not originated from the considered modem but from a remote station RING ATA CONNECT 9600 NO CARRI ER indicates an incoming call manually answer the call not applicable if ATSO 1 is set answer from modem connection to remote host is established baudrate between DTE and modem is 9600Bit s now the data transfer takes place every data passed to the modem will be sent to the remote modem the call has been terminated by the other side the modem switches back to on hook command mode Table 5 10 Example incoming data call 5 1 IRIDIUM Communication 80 These two examples show the most of the basics needed for the use of the A3LA IRIDIUM modem related to the CoolRobot project All other shown commands are only needed to adjust settings depending on the application the modem is used for either connected to a PC or to the Jackrabbit micro controller Table 5 11 gives a review o
171. mission of the GPS data string There can be all different kinds of problems in parsing the correct GPS position To exclude the most transmission errors the function to parse the NMEA data string gps get position makes some comparisons Programmed from Z World was the checking of the header which are the first 6 characters They also checked if the incoming string contains any valid GPS position data or if the number of satellites did not suffice for a position determi nation I also implemented a comparison of the directions of latitude and longitude If the header is not one of the known NMEA formats or if the NMEA data is invalid the navigation 3 2 Main program for autonomous navigation 25 algorithm will try to get a valid reading of GPS data once every second until it succeeds In the case of not having any valid readings for 30 seconds adjusted by GPS_inv_limit the robot will change into manual drive mode without driving any distance In that case a notice of GPS parsing error or GPS sentence invalid will be sent out to the modem This notice will also be sent if one of these errors occured once but the robot will start navigating once received valid GPS data If the current position was parsed properly the active waypoint is selected from the array of waypoints given by the user At startup the function recognizes that it was called for the first time if the variable wp start is 0 Then the initial distance to the active wa
172. motor speeds are set to backwards 100 After 4 seconds it makes a right turn with 90 speed compared to 100 for 18 seconds which is equal to a 60 degrees turn After that the robot will stop and continue with navigating at the desired speed If called from drive mode wp follow full drive mode 1 the motor speeds are set to 100 and if called from wp follow partial drive mode 2 the motor speeds are set to 60 high tilt interrupt navigation cycle 2 cp 1 navigation cycle i cp 1 cp 2 Figure 3 24 High tilt angle interrupt handling sample Figure 3 24 shows the track of a high tilt angle interrupt After the motor speeds have been set to the speed before interrupted the navigation algorithm will start over again The second function checked once every second is detecting a high centered position In case 3 3 Analog sensors 50 of one wheel being without contact to the snow the current will drop to the no load current value The motor velocity will increase a little to almost the maximum revolutions That only is not a criterion to detect a high centered position because the Cool Robot will travel with only three wheels in contact to the snow repeatedly What I am doing is i check all four wheels once every second for a current value that is close to the no load current value If that is the case I check the motor velocity as well If the motor velocity is above 4950 rpm I log the tilt angles The number of t
173. n 1 end function U ULL TT BeginHeader sensor high centered int sensor high centered int tm hc int wheel air extern float output 15 extern float tilt hc 2 EndHeader START FUNCTION DESCRIPTION ACkCkCk ck ck ck ck kck ck k ck ck k ck ck ck ck ck ck k ck k k kk kk void sensor high centered int tm hc int wheel air lt analogin lib gt SYNTAX void sensor high centered int tm hc int wheel air and set drive mode to 3 high centered RETURN VALUE 1 if high centered 0 otherwise KEY WORDS DESCRIPTION will check the sensors readings and look for a high centered position 10 D 1 analogin lib 172 END DESCRIPTION OKCKCKCKCkCkCk ck kCK Ck kCk Ck kc k k kc k k k ck I OR OK kx int sensor high centered int tm hc int wheel air int i count motor_speeds if tm hc 10 tm hc 0 wheel air 4 drive mode 3 return 1 end if else if wheel air 3 if output wheel_air lt 0 3 amp amp output wheel_air 4 gt 4800 if abs tilt_hc 0 output 8 lt 5 amp amp abs tilt_hc 1 output 9 lt 5 tm hc 1 end if else tm hc 0 wheel air 4 end else end if return 0 end else if else if wheel air 5 tm hc 0 return 0 end else if else for i 0 i lt 4 i count motor speeds if output i lt 0 3 amp amp output i 4 gt 4800 tilt hc 0 outpu
174. n has to be based on waypoints and GPS data only because a magnetic compass does not work on the high magnetic latitudes on the Antarctic Plateau Reference 5 completed the robot design including CAD models of all components and structural analysis The mechanical design of the robot is based on a very light but strong honeycomb composite made of fiberglas and Nomex This thesis describes three different parts of work on the Cool Robot 1 assembling of the chassis 2 navigation and control 3 communication and datalogging Table 1 1 Main topics of work on Cool Robot The first part is the assembling of the honeycomb chassis and the motors and drive trains CoolRobot project started in winter 2003 2004 with the conceptional work During the sum mer 2004 Alex Streeter Alex Price and Dan Denton made most of the mechanical parts for the robot The honeycomb panels were cut in pieces for the main chassis the solar panel at tachment arms the stiffeners and the lid The EAD brushless motors were mounted to the gearhead and ready for their implementation in the chassis The aluminum rims for the 16 inch or the 20 inch ATV tires were welded to the axis On the logic side the jackrabbit itself was ready for testing because it was mounted to the evaluation board The circuit for the 8 channel Analog Digital Converter MAX186 for reading the analog sensors and the Digital Analog Converter MAX536 to control the motors was build The desig
175. n lib A float to convert the 12 bit output value to motor velocity Channel 4 5 6 and 7 are converted to motor velocities A B C and D The input range is 5 volts and 1V output voltge 120Hz 5 120 60 4096 0 2 Hall frequency default tilt lim analogin lib An integer value for the maximum roll and pitch angle in degrees at which the robot should be interrupted and stopped default 45 tm_he main_prog An integer that defines the time the function sensor_high_centered waits until it switches the drive mode to high centered The value is the time in seconds default 10 sec tm_nav main_prog An integer that defines the time between current point 2 and current point 1 for each naviga tion cycle in the drive mode wp follow full in seconds The time for the course corrections will be added default 30 tm nav low main prog An integer that defines the time between current point 2 and current point 1 for each naviga tion cycle in drive mode wp follow partial if the power does not allow waypoint following at full speed in seconds The time for course corrections will be added default 2 50 The time is automatically calculated with the value of tm nav tm nav wp drive lib An integer that defines the time between current point 2 and current point 1 for each navi A 1 Overview of parameters and variables 154 gation cycle once within a range of 100 m to the last active waypoint in
176. n of the solar power system is the work of Alex Streeter s M S Thesis Five separate custom built solar panels feed power onto a common bus which is then distributed to the motors and housekeeping electronics A bank of Li Ion batteries act as a buffer for the bus and provide auxiliary power The first part of our work was to assemble the chassis adapt the motors to the chassis and provide the support tubes for the axis Configurating the microcontroller to communicate with the ADC the DAC the GPS unit the Datalogger and the modem would be the main part of our work Finally we had to program the different algorithms to drive the motors read the different sensors communicate with the modems read the gps data and control the robot in various modes of operation Toni s main tasks are the communication between the robot and a human operator and the storage and retrieval of data the robot collects during it s journey The only way to stay in touch with the robot while it is traveling around on the Antarctic Plateau is a connection over IRIDIUM modem which is at the moment the only provider of truly global mobile satellite voice and data solutions The system provides a complete coverage of the earth s oceans air ways and most important for our application the polar regions With this connection the robot is able to report problems transmit a portion of the collected data or request new waypoints On the other hand an operator has the
177. nNr wp rcvd 7 3 The main loop 128 case 3 case 4 case 5 default wfd cof serEputs out string wp rcvd 0 send event 0 break sprintf out string DrMode d Mot SpeedA dB dC dD d n r drive mode motor speed 0 motor speed l motor speed 2 motor speed 3 wfd cof serEputs out string send event 0 break FSrc fopen rd amp logfile LOG FILE NAME if FSrc 0 fseek amp logfile 32 SEEK END FSrc fread amp logfile buf 32 if FSrc 32 fclose amp logfile sprintf out string last 32 bytes of logfile s n r buf wfd cof serEputs out string else wfd cof_serEputs no data found n r else wfd cof serEputs could not open logfile n r send_event 0 break wfd cof serEputs out string send event 0 break break In addition to the switch case statement there is a short piece of code within an if statement which is only active in manual drive mode The first line is just a time delay of ten seconds using the keyword wait for in combination with the delay function DelaySec which returns a zero until the specified time is elaped As long as wait for receives a zero the execution will jump out of the costate and the next time execution hits this costate it will directly jump to the wait for ignoring the code beforehand This means in manual drive mode all answeri
178. ncluding the AT prefix Spaces carriage return lt CR gt and line feed lt LF gt do not go into the buffer and therefore don t count against the 39 character limit In case of a syntax error within the command line or if the 39 character limit is exceeded the whole command line 5 1 IRIDIUM Communication 74 will be ignored and an ERROR result code will be returned Possible result codes are shown in Table 5 11 5 1 1 2 Outline on AT commands In this section some of the most common commands of the AT command set will be intro duced Essential commands will be explained by some examples including result codes as answers from the modem With this short introduction the reader should be able to originate a data call switch between in call data mode and command mode end a call and adjust some basic settings that might be important for use within the CoolRobot project So called escape sequence switches from in call data mode to in call command mode The modems answer is OK AN The answer command A forces the modem to answer an incoming call immediately A Repeats the last command issued to the modem unless it was reset or power was interrupted A is not followed by a lt CR gt The answer depends on the last command AT As mentioned earlier AT is the prefix for all commands except the repeat instruction A and the escape sequence AT entered on its own forces the modem to answer OK p
179. nd commented out The variables lata laty etc can be defined as double lata but there are functions to convert float to double and the other way around The most important functions are presented here to allow an easy user interface double dpMakeNum long Num1 long Num2 Should only be used if the source code line is generated with the PC program This takes two long numbers and takes the bytes in the long numbers and combines them together for the bytes in a double precision number It is not intended to be used to convert long numbers to double double dpFloat2Double float Num Converts a floating point number to a double precision number Note that since computers work in base 2 and not base 10 things like 0 1 become 0 1000000014901161 This is an artifact of the base 2 representation I fill in the missing second byte with zero s but the zero s in base 2 are not zero s in base 10 float dpDouble2Float double Num Converts a double precision number back to floating point This doesn t round so the last bit may be in error double dpAdd double Num1 doubleNum2 Adds two numbers and rounds the final result Issues with infinity in the IEEE 754 format are not supported Also zero very small numbers around 1e 300 will cause zero to not quite be zero and may result in something like 1 2e 300 For numbers that aren t at the extremes however zero is zero double dpSub double Num1 doubleNu
180. new waypoints The variables drive mode and send event are set by this function according to the incoming command line and waypoints are stored in the wp list using the 7 3 The main loop 126 function str2wayp char GPSPostion All incoming strings that are neither waypoints nor a command or a modem output are ignored since they are either unimportant or a drive string for the manual drive mode For more detailed information on this function see the commented code of library RADIOCOMM E LIB costate processModemStr in string if status modem 2 switch drive_mode case 1 wp_follow_full break case 2 wp_follow_partial break case 3 got stuck in string break case 5 if strlen in string 0 manual drive in string break default break memset in_string 0x00 sizeof in string After analyzing the modem input the actual drive mode is entered but only if there is an active radio connection to the base station status modem 2 otherwise no drive mode will be entered and the robot remains inactive Which drive mode is executed depends of the value of the variable drive_mode A switch case statement selects the drive mode according to the integer value drive_mode carries The default case is only existent to trap a runtime error if drive_mode is for any reason not holding one of the valid values Important is the break keyword at the end of every case
181. ng function within the switch case statement are disabled If there is a need for other answers the whole if statement can be moved into an own costate after this costate Only the line memset outstring should be added to this costate too to avoid problems 7 3 The main loop 129 when filling the out_st ring again if drive mode 5 1 waitfor DelaySec 10 sprintf out_string A dB dC dD d n r motor_speed 0 motor speed 1 motor speed 2 motor speed 3 wfd cof serEputs out string The last part of the modem output section is not used to send actual data back to the remote station but to try to connect to this station as soon as a modem on is detected There fore this part is not enclosed in the big if status modem 2 statement it has its own elseif statement to detect 1f the modem is on but not connected status modem 1 In this case the command to connect to the base station is passed to the modem just once the modem will then try to reach the station carrying the callsign GOEK for round about 50 seconds Limitation to one attempt is made by the second if statement and the counter vari able tm count If the modem should try connect for a longer time this part must be changed slightly if tm count 0 mustbe changed to something like if tm count lt x and a waitfor DelaySec y should be added in front of the w d with y somewhere above 50 seconds The robot will then try to connect fo
182. ng_point GPSPosition c GPSPosition bp float tcl extern float dist_bp EndHeader START FUNCTION DESCRIPTION CKkCkCk ck kCk ck ck ck ck kk ck k ck ck A Z KA kk ck k ck ck k ck ck ck k ck ck kk ck k k kk kk gps bearing gps lib SYNTAX float gps bearing GPSPosition c GPSPosition bp tcl A EYWORDS gps DESCRIPTION Calculates lat and lon of a basing_point bp at a certain distance dbp from starting point c with the initial bearing tcl PARAMETER1 c starting point PARAMETER2 bp basing point PARAMETER3 tcl in true degrees RETURN VALUE Gl SEE ALSO END DESCRIPTION OKCKCKCKCKCKCkCk kCK Ck kCKCkCk CK Ck kCK Ck kCKCkCkCKCkCkCKCkCkCK Ck kCk Ck kc k k kc k kk kk ckok kk koe I gps basing point GPSPosition c GPSPosition bp float tcl float lat c lon c lat d lon d dist dummy2 int dummy lat c c gt lat degrees c gt lat minutes 60 if c gt lat direction S lat c lat c lat c lat c PI 180 lon c c lon degrees c gt lon minutes 60 if c gt lon direction E lon c lon c lon c lon c PI 180 D 3 gps lib 199 t cl tcl PI 180 dist dist_bp GPS_EARTH_RADIUS lat_d asin sin lat_c cos dist cos lat_c if cos lat_d 0 lon_d lon_c endpoint a pole else lon d lon c asin sin tcl sin dist dummy int lon d 2
183. nition of latitude and longitude The latitude degrees start from the equator with 0 to North and South Pole with 90 N or S The distance between two latitude degrees is 15 always the same and does not change For one latitude degree being divided into 60 arc min utes which have a distance of nautic mile the distance between two degrees is 111 136 km One latitude minute is again divided into 60 seconds Longitude degrees and minutes are also divided into 60 arc minutes and these again in 60 arc seconds The longitude is measured up to 180 west or east The distance between two longitude degrees is not constant and changes with latitude The following chapter deals with the main navigation algorithm of the Cool Robot The most important terms are explained here for better understanding waypoint A waypoint is a GPS position consisting of latitude and longitude transmitted to the robot by the user A maximum of 100 waypoints can be saved in an array By means of the waypoint coordinates and the current position the distance to the waypoint and the heading can be calculated current point A GPS data string in NMEA format from which the current position of the robot is parsed Used to calculate and correct the traveled course basing point A GPS position generated in a distance given by the user on the track connecting two waypoints In our case they are generated every 1000 m to reduce the offset from the track
184. nt 2 18 bit binary integer 3 bytes per data point numbers to the right of the decimal are truncated 3 RAWS7 7 possible data points for total rainfall wind speed vector average wind direction air temperature RH percentage fuel stick temperature and battery voltage Fixed decimal ASCII xxx x Fixed decimal ASCII xx xx Fixed decimal ASCII x xxx Fixed decimal ASCII xxx Fixed decimal ASCII xxxxx oo VA U R Table 6 3 Possible values for DataFormat Both commands are intended to be used with sensors that use serial communication to output their measurement data The problem herein is that the datalogger and micro controller are not able to establish a real communication using those commands there is no guarantee that data is synchronized at the datalogger and is stored correctly The other way around there is no possibility to request a certain section of the stored data since the datalogger is only intended to controll sensors using its serial ports not the other way Storing data from the micro controller to the datalogger should not be a big issue using the SerialInput instruction The other way around I don t see an obvious possibility to retrieve certain pieces of the earlier stored data from the datalogger to pass it back to the operator via the radio link The only idea is to find out how exactly the datalogger is communicating with a personal computer and imitate the PC s behavior with the micro controller 115 Chapter 7
185. ntrol register sectioning lt lt lt lt 44 4 41 Straight binary vs twos complement output format 42 Circuit to bias bipolar signals about Vref lt lt lt lt lt lt 43 ADC DIN and DOUT with analog input signal 43 Velocity monitor out vs motor revolution lt lt lt 47 High tilt angle interrupt handling sample 49 SPI nterface Rc DLE DER 54 DAC L6 bICdala Word aons qnom RR mee SCR Bee eo 54 Voltage output vs digital input lt lt lt lt ele 33 Motor revolutions vs input voltage lt lt lt lt eee 56 Flowchart of drive mode waypoint following at fullspeed 59 Screen shot of dynamic C code for waypoint following at full speed 60 Overview of motor placement e oe Qe tne Sr d od in as 63 Drive mode Charae Cycle c 2 uo xoxo 8 Se om eS oC A RE INR 64 Drive mode stationary get data lt lt 44 ee 65 Example for an IRIDIUM modem application 69 FDMA versus TDMA Sa Re Re X heehee hathe gio iUx Tei xd 70 Motorola 9505 A3LA I IRIDIUM modem 71 SAF2040 E mobile flat mount antenna lt lt lt 4 71 Some sample commands with explanation AT manual for A3LA 73 Example for different ways to type commands AT manual for ABLA 73 Components needed for packet radio communication 82 KPC3plus front view Sa S bes ied heed aie ha
186. o 20 channels and each of those channels is time divided into 4 TDMA channels This multiplies to 80 channels per cell Considering that each of the 66 satellites has 48 cells this makes up a total of 3168 cells Only 2150 cells are active at a time multiplied by 80 channels per cell the system allows up to 172000 calls simultaneous The bandwidth for each of the channels is 2400Bit s when transmitting data and 4800Bit s on a voice call 5 1 1 The A3LA I IRIDIUM modem The IRIDIUM modem or IRIDIUM Subscriber Unit ISU used when Cool Robot will be deployed in the Antarctic is a Motorola 9505 A3LA I The unit will not be purchased but rather borrowed for Cool Robots mission in the Antarctic Thus no example is available for testing at the moment I was only able to familiarize myself with some facts as well as the handling and operation of this equipment 5 1 IRIDIUM Communication 71 Figure 5 3 Motorola 9505 A3LA I IRIDIUM modem Other than normal IRIDIUM mobile phones this modem is special designed for the use with computer or micro controller based applications Using the modem alone no IRIDIUM call can be completed because some additional equipment is needed An antenna is required since the modem doesn t come with one Lots of different antennas for almost every requirements are available on the market The one preferred for our project is the NAL Research SAF2040 family of mobile flat mount antennas They are designed to withstan
187. o accelerate in steps of 10 up to 40 and then take a left turn by decreasing the left wheel speeds by 20 and increasing the right wheel speeds by 20 To keep track of the actual motor speeds the robot sends them back to the base every 10 seconds kpc3plus HyperTerminal File Edit View Call Transfer Help GPS parsing error CRCHDHANDM A 0B 0C 0D 0 wa A 50B 50C 50D 50 aawwww A 60B 60C 100D 100 dd A 80B 80C 80D 80 SSSSS aa A 30B 30C 30D 38 A 16B 10C 50D 50 q 8 0B 0C 0D 0 Figure 5 19 Screen shot of Hyperterminal while in manual drive mode The interval for the motor speed sending is intentional chosen quite long to keep the data traf fic low and guaranty that commands to the robot are delivered as fast as possible When Cool Robot resides in manual drive mode it will only move if an radio connection is established and if the connection is lost the robot will stop immediately after it realizes the disconnection This takes about 60 seconds because the modem resends packets for this time before the connec tion is determined as lost Besides it is not possible to access the manual drive mode without an active radio link One additional controll key is implemented in the actual version of the manual drive mode By sending a p character the robot stops immediately and switches to waypoint following at full speed Normally drive modes are switched by another command as described later on in th
188. o interrupt driven to prevent the robot from tipping over wp follow partial The same routines as in the drive mode wp follow full are run except that the robot travels with a speed of 60 manual operator The Cool Robot is not navigating autonomously The GPS data string send out to the serial port and the motor speed command to the DAC in percent are send back to the radio modem connected to the Laptop and are displayed in the HyperTerminal window The robot can be controled with the keypads w 10 motor speed increment s 10 motor speed reduction a left turn with 10 difference in motor speeds left to right d right turn with 10 difference in motor speeds right to left g stop decreases all motor speeds to zero within 1 second p switch to wp follow full motor speeds set to zero high centered This drive mode is accessed when the wheel speed sensors and the motor currents create the interrupt in one of the waypoint following drive modes The Cool Robot tries to get all four wheels back in con tact with snow This routine has to be evaluated during the testing in Greenland 4 2 12 bit Voltage output DAC with serial interface 53 charge cycle The navigation is reduced to parsing the GPS Position from the GPS data string The motor controller are shut down and the power consumption is reduced to a minimum Accessed by the Slave con troller maintaining the power overall power su
189. o the circuit board of the radio But none of the things we tried worked out So we borrowed another set of hand held radios two ICOM 4088 from Prof Cooley because for ICOM radios some wiring examples were available within the KPC3plus manual The most reasonable of the different suggestions to do this wiring was using the microphone and speaker jacks available on top of the radios As suggested in the KPC manual 5 wire shielded cable was used To keep electro magnetic interference as low as possible only the very last centimeters of the cable are unshielded and the capacitor as well as the resistor are placed within the housing of the microphone plug Figure 5 13 Wiring suggestion for ICOM radios 5 2 Radio Communication 88 This setup worked quiet well and so proved that it is possible to transfer digital data using the Kantronics packet radio modems and some commercial hand held radios as transceivers 5 2 1 2 Using the KPC3plus If the KPC3plus is started for the first time or after a reset it is running its AUTOBAUD routine trying to negotiate the baud rate with the terminal it is connected to Therefore it is sending a request to type a KPC 3000 HyperTerminal File Edit View Call Transfer Help joe 8 BEF ftf PRESS TO SET BAUD RRTE MC eeCCCCCCCCCCCCCCCCCCCCCC ENTER YOUR CALLSIGN gt goek KANTRONICS KPC3PMM VERSION 9 0N C COPYRIGHT 2002 2003 BY KANTRONICS INC ALL RIGHTS RESERVED D
190. obot will be following waypoints on the Antarctic Plateau but if the power budget runs low the robot has to stop to recharge the li ion batteries Once standing at one position without driving the motors there is no use of calculating distances and bearings The navigation algorithm can be shut down To meet the different requirements drive modes for the Cool Robot are implemented A drive mode grades and arranges the different base functions used to read the sensors to control the motors or to navigate for example A detailed overview over the Cool Robot s drive modes is given in Table 4 2 The drive modes and a general description are listed below wp follow full In the drive mode waypoint following at full speed the robot travels at 1 32 on the calculated track to the next active waypoint High energy consumption wp follow partial Called from the drive mode waypoint following at full speed when the Slave microcontroller sets a power limit which forces the motors to run slower Still heading to the waypoint manual operator in string Designed to have easy manual control over the robot to drive 4 4 The different drive modes of Cool Robot 58 it into a garage instead of carrying it Highest priority and interrupt driven in all other drive modes Control via keypad w faster a left s slower d right q stop high_centered in_string Detected and called by the motor current and motor velocity sen sors if the Co
191. oggers 6 2 The Campbell CR5000 and CR1000 dataloggers 110 SCWIN CR1000 DiProgram Files File Edit Settings Help Selected Sensors Generic Measurements Meteorological Patt Volt Barometric Pressure Precipitation E CS700 Rain Gauge Bl Generic Tipping Bucket Rain Gauge B MetOne 380 385 Rain Gauge B MetOne 380M 385M Rain Gauge E TB4 Rain Gauge B TES25 TE525WS Rain Gauge B TE525MM TE525M Rain Gauge Relative Humidity amp Temperature Soil Moisture Solar Radiation Wind Speed amp Direction Miscellaneous Sensors Temperature Water Calculations amp Control 3 Calculations CR1000 Add Device Double click a folder icon to see the sensors in that category 1Sensors 2 Wiring Diagram 3 Wiring Text Sensors Measurements Figure 6 5 Screen shot of Short Cut second step choosing sensors Short Cut allows to select the interval of the measurements different sensors and the tables the data should be stored to and Short Cut builds the program for the specified datalogger type This program file can be edited and extended afterwards using the CRBasic editor Thus Short Cut makes it pretty easy to create routines for the basic measurements and also collecting data from sensors using RS232 serial communication 6 2 The Campbell CR5000 and CR1000 dataloggers 111 SCWIN CR1000 DiProgram Filesi CamphellSciscwintuntitled scw Scan Interval 5 0000 S g Fil
192. ogocgcgoscosgossg SS So ST STS SST 0 093 0 077 0 052 0 033 0 088 0 072 0 051 0 028 0 086 0 066 0 046 0 026 0 090 0 067 0 085 0 059 0 037 0 018 0 092 0 078 0 055 0 031 0 098 0 082 0 061 0 046 0 023 0 099 0 082 0 063 0 040 0 022 0 092 0 071 0 050 0 035 0 018 0 099 0 079 0 063 0 048 0 026 0 091 0 081 0 082 0 075 0 058 0 039 0 020 0 083 0 062 0 038 0 023 0 085 0 062 0 036 0 017 0 086 0 060 0 042 0 024 0 089 0 064 0 041 0 020 0 083 0 055 0 034 0 086 0 065 0 046 0 021 0 082 0 057 0 028 0 080 0 067 0 041 0 019 0 084 0 061 0 039 0 014 gc occocgcoccccoccccszc gm OocOcOGcOoccccoccoccccoccoccccccocccces gm OocOcOGcOocccocccocccccocccccccocccccs coccoeccccssc S S 39 7 422 38 8 304 38 5 362 313 44 0 41 5 40 1 443 45 7 32 2 27 1 38 2 42 0 44 1 ShA 26 2 28 3 ST 32 7 25 0 26 4 25 8 27 8 30 8 25 0 26 4 25 2 24 6 2749 27 0 26 7 26 1 25 7 26 6 26 4 274 28 1 313 34 3 23 9 227 9 247 7 278 1 309 6 343 6 50 0 196 8 198 4 198 3 205 8 214 7 219 6 217 3 243 7 215 0 213 3 217 1 235 4 213 6 217 1 222 1 221 0 213 7 215 4 218 1 209 9 207 2 212 0 208 5 328 5 343 3 353 5 307 8 305 2 314 2 339 3 312 8 318 3 328 0 356 0 e ree r r e er e r eae OoGcOoGccocococcocooccocococoococ OGcOoGccoGcocoococococoocoococoocoococoog ococcococco 0 017 0 016 0 017 0 016 0 016 0 016 0 017
193. ol Robot is high centered A routine that turns the wheels forward backward turns left at 100 and 100 to get the Cool Robot unstuck again charge_cycle Accessed only from the drive mode wp_follow_partial if the power budget allows no further propulsion Parameters have not been selected at this point and need to be set by the Slave microcontroller appropriate for the energy consumption high wind A drive mode that has to be implemented once the wind speed sensor is attached Will turn the robot into the direction of the wind at high speeds gt 2077 Should prevent the robot from tipping over because it is facing the wind from the side or being tilted at one corner so that the wind is able to get under the robot Should also move the robot a few meters to prevent it from getting snowed in stat get data The Cool Robot has a scientific assignment To take measurements it has to stay on one position In that case the bigger part of the bandwidth of the iridium communica tion is reserved for the payload for example 4 4 The different drive modes of Cool Robot 59 4 4 1 Waypoint following at full speed The drive mode wp_follow_full is the main drive mode for the Cool Robot In the best case the Cool Robot only exits this drive mode for stationary data acquisition Unfortunately there are factors which force the Cool Robot to exit that drive mode On the Antarctic Plateau very high wind speeds are not uncommon In that
194. ometers are used for the CoolRobot to detect a maximum pitch or roll angle to prevent it from tipping over if driving while climbing large sastrugi features An accelerometer mg tilt has a varying sensitivity in the range of 1g to 41g The output changes with nearly 17 5 when the accelerometer is perpendicular to gravity but the resolution decreases and the output mg etilt changes at only 12 2 at 45 The analog output voltage Vout 1 5V lt Vou lt 3 5V is converted to a range between 1V lt Zout lt 1V in the function read_sensors written in the analogin lib library With 1V 1g the output tilt in degrees can be calculated as pitch arcsin g 3 12 roll arcsin 4 3 13 3 3 Analog sensors 46 One thing to keep in mind is that both outputs can exceed the output range of 1V to 1V due to vibration or shocks by falling down a steep and sharp edge of a snow feature To prevent a domain error when trying to calculate the arcsin x for x gt 1 I round the output ranges off to 1 if they are larger At 45 tilt which is the stalling angle Zout OF Yous has a output of 0 707V defined as the critical tilt value see chapter 3 3 6 To reduce the influence of vibrations on the outputs Zout and Your of the tilt sensors a 2 4 order Butterworth Filter acting as a lowpass is integrated in the circuit The bandwidth then is given by 1 2 r V2 REG with R 22kQ and C 0 luF we have a bandwidth
195. on board M12 is provided with 10 V supply voltage The I O command format is Motorola Binary at 9600 baud The commands can be used to initialize configure and control the receiver The receiver does also provide I O commands in NMEA 0183 format at 4800 baud but these commands can only be used to change the transmitted GPS data string e g output rate For all I O commands see M12 receiver user s guide chapter 5 The best way to initialize the receiver is by using the software WinOncore on a PC The serial port has to be connected to the GPS receiver with the provided 9 pin serial cable The serial port on the PC has to be opened at 9600 baud If the receiver is started up after a longer non operated period of time the user should allow the receiver 3 to 5 minutes to power up That time is called TTFF Time To First Fix The receiver must now perform a Cold Start where position time and almanac information are not available The satellite almanac files each contain information about GPS reference week the almanac reference time required data to identify a satellite satellite health status longitude of orbital plane and more see ICD GPS 200 for detailed description Note that a cold start is not a serious problem but TTFF will be somewhat longer than if the information had been available The main thing to keep in mind is that the receiver coming up in a Cold Start scenario is defaulted to Motorola Binary protocol and NO MESSAGES are ACT
196. ongitudinal onto one of those features In that case the robot must be able to realize it is stuck which is part of the navigation process try to get itself unstuck and if this is not possible it has to send a status report back to the base This report must contain at least the position at which the robot got stuck to be able to pick it up It might also be useful to have all other available sensor data to get an exact idea of the situation With enough information about the actual situation of the robot it might be possible to free it by driving manually or 5 1 IRIDIUM Communication 68 with a special set of commands to move it based on the momentum of the wheels There are lots of other possible errors imaginable that could force the robot to stop For ex ample problems with the power system low batteries burned fuses or other hardware or software related problems Finally it might be necessary to know where the robot is and in what condition It is quiet possible that the robot is not going as fast as is supposed to and therefore is not able to finish the planned route within the time alloted for its mission So it is important to check the progress periodically and be able to alter the track or cover extra distance if it is ahead of schedule Depending on the kind of scientific application of the Cool Robot it might also be necessary to send some of the measured data to base 5 1 IRIDIUM Communication Within the concept developmen
197. onnection 8 2 Overall energy consumption on snow 143 between the waypoints is too much The second case with a distance of 500 m or more between the basing points is within a good range With a total track length of 500 km the robot would travel 515 km which is equal to 103 Further testing with varying parameters in Greenland has to evaluate the best navigation behavior The opposite is that the offset from track is within a small range while heading for the basing points in a small distance but as seen in Figure B 2 is the offset from track within the range of 20 m controlled in the navigate lib 8 2 Overall energy consumption on snow The overall energy consumption on snow is basically the same as the energy consumption of the motors The Jackrabbit and the peripheral parts draw only currents in the range of milli amperes The following current data was taken on the golf course of Dartmouth College on february 18th which was a test with the 16 inch tires on it The sun was shining and the temperature was 34 F 1 C currents on snow 35 JE fy a ethos Ed Ze ERE current all U The n smooth all overall mea f j btt d n ES mU M e 7 ALME M 0 20 40 80 100 120 sec Figure 8 6 Current draw data on snow 8 3 Rolling resistance 144 The snow was already a few days old and was pretty firm A lot of footprints had been made and the terrain was demanding Viewing t
198. onomous navigation 32 for the pole angle O I do the following transformations in the source code lat for direction S 3 2 lat for direction N lon for direction E lon for direction W For latitude and longitude on earth see figure 3 1 With these transformations every position on earth can be described by f r cos lon sin lat z f lona gt r sin lona sin lata y 3 4 lata r cos lat z The angle a in radians between two positions on earth then is calculated with the scalar product between the two position vectors cos lona sin lata cos lon sin lat cos a sin lon sin lat gt sin lon sin lat cos lata cos laty 3 5 cos lat cos lat sin lat sin lat cos lona cos lon sin lon sin lon The angle o would be easy to calculate by a arccos cos lat cos lat sin lat sin lat cos lon lony 3 6 but the double precision library does not include an arccos function So I had to convert the arccos into something known which is the arctan in this case arccos a arctan 2 arctan 1 3 7 a Vl a 3 2 Main program for autonomous navigation 33 The distance then is calculated with the angle converted to degrees and multiplied with the distance between two degrees dist km a 111 136 E 3 8 3 2 2 Calculation of gps bearing and off bearing The function
199. or incoming character strings from serial port E This purpose is served by the cofunction cof_serEgets destinantion maxCharacters timeout It is waiting for characters received on the serial port and reads them to the variable specified as destination until a carriage return line feed or NULL character is received or the the specified timeout is reached between two characters This function is located in an own costate because it blocks all other code within this costate following after this function until it receives a string and returns from execution If no string is received the function will not return and no other code within this costate will be executed As described at the beginning of this chapter different costates are executed seemingly simultaneous because they share execution time If one costate is inactive because its is waiting for something to do like the cof serEgets wait for an incoming string the next costate will get the available execution time And so on until the end of the loop is reached and the first costate is executed again All cofunctions must be called from a waitfordone 7 3 The main loop 125 wfd statement because the execution will restart at the waitfor or wfd statement it was transfered to the next costate while 1 costate wfd cof serEgets buffer sizeof buffer 2 500 if strlen buffer 0 memcpy in string buffer sizeof buffer termStr in string memset buf
200. or the first time wp start 0 the current position saved in current pos 1 is also saved in cur rent pos 2 These two positions are used to calculate the robot s bearing They are the trav eled positions 30 seconds apart in time wheras the time is an adjustable parameter tm nav For running through the navigation algorithm for the first time there is no current position from the last navigation cycle I had two different ideas of how to proceed on the startup in drive mode w follow full The first one is to place the robot pointing north The current distance at startup is 0 km and the calculated bearing between the two sample points is also 0 So at startup Cool Robot thinks his heading is north and makes a turn for the off bearing degrees between 90 and 90 depending on the initial bearing If the robot s heading is north in the best case the turning to the desired heading takes one navigation cycle as outlined in Figure 3 10 2nd navigation cycle cp 1 tet start point cp 1 cp 2 1st navigation cycle Figure 3 10 Startup procedure 1 with Cool Robot pointing north In the worst case the robot is pointing south instead of north at startup That will not cause serious problems but takes some more navigation cycles to head to the desired course to the waypoint or basing point as shown in Figure 3 11 3 2 Main program for autonomous navigation 27 4th navigation cycle 5th navigation cycle N epit cp 2
201. ot drive on with the motor speeds set before that error in most cases 100 The robot is now OUT OF CONTROL until the whole program is recompiled To debug the error the Laptop has to be connected to the Jackrabbit with the programming cable Recompiling the navigation program while running behind the robot with the laptop on one arm is not easy So I made different steps in testing the navigation algorithm and the drive modes wp follow full and wp follow partial At first I navigated with the laptop connected to the programming port while driving around in the car The problems appearing with the infinitesimal distance be tween the two navigation points were solved by using the double precision library To check the reliability I wanted to run the navigation algorithm for hours before taking the robot out One main field of major interest was the ability of the Cool Robot to climb sastrugi features and even whole sastrugi fields Therefor the robot was driven in the manual drive 8 1 GPS waypoint following position and navigation data 136 mode to the selected features Figure 8 1 Cool Robot navigating to a waypoint on lake mascoma For the testing of the waypoint following drive mode we took the robot out on lake mascoma near Lebanon Figure 8 1 The lake was frozen and covered with at least 45 cm of ice That provided us the opportunity to drive on the lake with the car and stay within the visibility range to the robot and con
202. ot within a certain range Within this section the reader will be introduced to the operation of Cool Robot via the radio link I am going to explain how a connection between robot and operator can be established and terminated how different types of data can be transmitted to CoolRobot how the data is computed and what the robots answers to certain requests are 5 3 1 Establish and terminate a connection Before attempting to connect Cool Robot and a remote station all the hardware should be set up properly At first the radio modem must be connected to the internal power supplies within the robot There is one connector for the housekeeping power supply which provides the radio modem with 10VDC The radio modem used with a laptop as control station and both radios run on batteries the modem requires a 9V block battery and the radios need 3 AA 1 5V batteries each When starting a test run both modems as well as both radios should be turned on before compiling the software to the Jackrabbit micro controller The channel used with the radios is not of importance and can also be changed during a run if there is any disturbance on the channel As described in chapter 7 4 different versions of the main control program are available for the use with the radio connection One of them mainprog v0 34 see chapter 7 for detailed description is totally based on an radio connection When the program is compiled to the Jackrabbit and the program starts
203. otor_speed k 0 UpdateMotorOutput end for return motor speed end else end while end main M L L LT LL LT T LTL BeginHeader DispStr void DispStr int x int y char s extern int x extern int y EndHeader TAC int y START FUNCTION DESCRIPTION KKEKKKKKKKKKKKKKKKKKKK KA x KG KG ko ko ko void DispStr int x int y char s lt drive lib gt SYNTAX DESCRIPTION PARAMETER RETURN VALUE Lu aN EY WORDS END DESCRIPTION OKCKCKCKCkCkCk ck I Kk k Koko kok kok X kk ke e x kx Set the STDIO cursor location and display a string void DispStr int x int y char s D 2 drive lib 179 x 0x20 y 0x20 printf xlB c Sc s x y S T LTL L TL TL P P TTT BeginHeader SwapBytes int SwapBytes int value extern int i0 EndHeader int i0 START FUNCTION DESCRIPTION KKEKKKKKKKKKKKKKKKKKKK x x KG KG Kk ko ko SwapBytes lt drive lib gt SYNTAX int SwapBytes int value DESCRIPTION The function SwapBytes is used to swap the order of the two byte output value This is necessary because the Rabbit and Dynamic C are Little Endian the LS byte is sent first The MAX 536 requires that the MS byte be transmitted first PARAMETERI 2 byte value RETURN VALUE Gl swapped 2 byte value A EY WORDS END DESCRIPTION eR I OK kx
204. ots axle bond together due to some small parts of aluminum in between This made big problems when trying to disassemble the drive train Therefore the suggestion is to use another material e g steel for the shaft collars in the future Maybe not only on further generations of Cool Robot but also before testing in Greenland and definitely before deploying it in the Antarctic 14 Chapter 3 The navigation and monitoring elements The navigation of Cool Robot is limited by the budget restrictions for the project Cool Robot is a low cost autonomous robot for Antarctica The fact that the magnetic South Pole and the geographic South Pole vary from each other does not have great effect on navigation by magnetic compass in our latitudes but the bearing difference does increase the closer one gets to the Poles Precise bearing information for navigation use on the Antarctic Plateau can be provided by a triaxial magnetic compass but is not intended for our project Due to expense the navigation for Cool Robot is based entirely on GPS Global Positioning System see chapter 3 1 Coordinate planes for determining positions on earth have existed for many centuries His tory has brought up many different ways of longimetry and goniometry Today the sys tem of latitude longitude and height is the most popular one The prime meridian in Figure 3 1 Lat and lon on earth Greenwich and the equator are the references for the defi
205. our wheels are at the same revolution speed at the different speeds the motor controller with the lowest reference gain at full speed has to be taken as a reference The offset potentiometer has to be turned so that all motors start turning at the same input voltage in both directions Due to static friction roughly 20 of input voltage must be commanded before the motors start turning Then the reference gain for each motor has to be adjusted at full speed in both directions to the reference wheel Only this guarantees a perfect straight track for the Cool Robot Figure 4 4 RPM reference gain Figure 4 4 Motor revolutions vs input voltage 4 4 The different drive modes of Cool Robot 57 As shown in Figure 4 4 the output voltage is not linear to the wheel speed The drawing on the right side shows how the motor speed behaves compared to the input voltage provided from the DAC The brushless dc motors DA23 DBB M300 from EAD Motors are mounted to the gearhead with a 100 1 ratio A maximum revolution after the gearhead of 50 rpm and a tire diameter of 20 inch provides a top speed of 50rpm 9 10inch 2 54m Vas ee ve 100 gg 4 2 8 4 4 The different drive modes of Cool Robot On the trip over the Antarctic Plateau the Cool Robot has to face many different situations Some algorithms and functions have a different priority during the trip The best example is the navigation algorithm Most of the time the Cool R
206. pdates the DAC s output The motor controllers are supplied with 48 Volts as well as the mo tors themselves The speed of each motor is controlled with the DAC s output This chapter will explain the design and construction of the DAC setup together with the motor controller The DAC is connected to serial port D Table 4 1 shows all serial port connections on the jackrabbit serial port function programing and compiling port analog to digital converter AD7490 GPS receiver Motorola Oncore M12 digital to analog controller TLV5614 radio modem iridium modem HOROU gt Table 4 1 Serial port connections and functions for RCM 4 1 Navigation and control mode overview 52 4 1 Navigation and control mode overview Table 4 2 summarizes the navigation and control modes assumed for the robot wp follow full The Cool Robot drives at the top speed of 1 27 and navigates au tonomously to follow the given waypoints and the generated basing points The GPS receiver is set to output the NMEA GPRMC mes sage once every second The robot will parse its position once every 30 seconds after achieving the last course correction to calculate the current bearing and the next off bearing While traveling the analog sensors are read once every second The wheel speeds and motor cur rents are compared to detect a high centering position and switch to the drive mode got stuck The tilt sensors are als
207. possibility to check the condition of the robot request data and send new or changed waypoints When the robot is deployed in the Antarctic it will equipped with an IRIDIUM transceiver The big disadvantage of this system is the high price for this unlimited availability The transceiver itself is priced around 1200 and every minute of connection costs 2 within the United States and 7 elsewhere in the world Therefore an other cheaper system will be used during the development of the robot and the first field tests in Greenland The easiest way to establish a wireless connection and transmit digital data is a radio connection using a data modem With the help of two handheld radios and two radio modems one is able to control the motion of the CoolRobot manually or monitor the behaviour of the machine while navigating autonomously over a distance of approximately 2 km The CoolRobot will also be equipped with a datalogger to record scientific data from the payload This data is analog and can be retrieved when the robot returns to its base Especially during testing and the first run in the Antarctic all the sensor data the robot uses is a matter of particular interest So all this digital data will be stored too The latest sensor readings will be stored within the limited flash memory of the microcontroller If the robot encounters a critical situation this data will be send to the operator who then is able to reconstruct the situation of th
208. pply as a part of Alex Streeter s master thesis high_wind The robot is turned with one corner facing the wind Energy con sumption is reduced to minimum in case of a blizzard Movement of twice the length of the robot once in a while to prevent snowing in Not implemented at this time stat_get_data The drive mode in which the robot mainly does nothing The largest part of the bandwidth is reserved for the payload data transmission Table 4 2 Control and drive mode overview The main control algorithm for the Cool Robot is split into different drive modes A drive mode is the summarization of the basic functions needed to handle the current situation As the circumstances change during the robot s trip the priority for each algorithm changes The main active program on the Master controller maintains the connection to either the radio modem or the iridium modem see chapter 5 and also changes the drive modes if needed see chapter 4 4 More drive modes are designated but not implemented yet because the needs for the scientific payload are not specified and the wind speed sensor is not implemented yet see chapter 4 4 4 20 12bit Voltage output DAC with serial interface Selected for our drive train was a Digital to Analog Converter from Texas Instruments because they had the best support with their package The digital supply voltage is separated from the analog side and can be varied between 2 7V and 5 5V
209. quipped with 20 inch tires instead of the 16 inch tires it was running at the moment The benefits herein are a 2 inch increased ground clearance and due to the fact the 20 inch tires are slightly wider also a decreased ground pressure and sinkage Furthermore the tread pattern of the 20 inch tires seemed more efficient for driving on snow than the pattern of the 16 inch tires So we switched to the larger tires This procedure took almost one day since it was quite a bit of work to remove the small tires from the rims Removing the first half of the rims was pretty easy using clamps to compress the tire until one of the two halves was free To remove the second half from the tire we had to use clamps and wood to move it step by step In contrast putting the new tires on was pretty easy and involved putting both halves of the rims together with some new sealing compound and the new tires in between and inflating the tire to about 30psi until the tire pops into the correct place on the rim To help the tires sliding on the rim some soap and water was used as lubricant The last part of the Assembly process was fitting the top lid to the robots chassis The first step was cutting the sidewalls of the lid to their final height and drilling the holes for the inserts This was not easy since the inserts on the chassis sidewalls were not exactly in a straight line and in perfectly equal distances to each other So we had to custom fit almost every hole to a
210. r string and the termination character Termination_Char is the character that will be used to mark the end of the transmitted string This number must be less than 128 FilterString is a string of characters used to mark the beginning of the data transmitted from the serial sensor GOESData ResultCode Table TableOption BufferControl DataFormat The GOESData instruction is intended to be used with a SAT HDR GOES satellite data transmitter The data transfer to the transmitter can occur via the datalogger s CS I O port only If the datalogger is sending a command all further tasks will be executed only after a response is received The big problem with this instruction is that it uses the CS I O port instead of the RS232 port like SerialInput and it might block the measurement routine if there is no answer to a command The GOESData instruction has the following parameters ResultCode parameter is a variable that holds a result code indicating the success of the program instruction The result codes are as follows Code Description Command executed successfully Timed out waiting for STX character from transmitter after SDC addressing Wrong character received after SDC addressing Something other than ACK returned when select data buffer command was executed Timed out waiting for ACK CS I O port not available ACK not returned following data append or overwrite command NYDN KR O UV Table 6 1 Possible val
211. r x times and the overall time for the connection attempt is simply z y else if status modem 1 if tm count 0 wfd cof serEputs connect goek r tm count t t memset out string 0x00 sizeof out_string 7 4 Different versions of the main programm 130 7 4 Different versions of the main programm The main program as it is described in this chapter is only one of a number of different ver sions and varieties derived from this version The visualized mainprogV0 34 combines al most all advances yet made except the capability of measuring and storing currents Although the required software is written it is not implemented in this code because of continuous prob lems with the MAXIM analog to digital converter As mentioned earlier chapter 5 3 1 the mainprogV0 34 depends on a active radio con nection nothing will happen without being connected On the other hand if the connection is lost for some reason the robot will stop whatever it is doing and remain inactive until it detects a connection again For longterm tests with the navigation algorithm where is no need to keep track of the navigation while it is running and only the analysis of the data after the run is important I changed the existing main program so that it is not as addicted to the radio connection any more 7 4 Different versions of the main programm 131 Initialize filesystem Check Modem on Wait until mo
212. rack is generated and the robot follows that new bearing Figure 3 14 3 2 Main program for autonomous navigation 30 navigation cycle i 2 bp i 1 N navigation cycle i 1 navigation cycle i course correction Figure 3 14 Basing point generating example drawing 3 2 1 Calculating the distance between two gps positions The function to calculate the distance between two positions was already written as part of a diploma thesis But when I first tested the waypoint following or especially the navigation algorithm with some special values of the two longitudes a domain error was produced in the gps bearing function In one example case the algorithm tried to calculate arccos 1 238 which is impossible I figured out that one problem was the gps ground distance function whose result is used to qualify the bearing There were two different errors in the gps ground distance function The distance was originally calculated by lon lom 2 lat laty dist 2 arcsin y cos lata cos lat sin sin s 3 1 Let me explain the problem considering as example the two positions a and b from the testing on the golf course on jan 11 2005 in dd mmmmmm azat and in radian lata Qiat 43 428442 lat 0 76295445 rad biat 43 428420 laty 0 76295381 rad Qion 2 1 70198 long 1 26158792 rad j V V o bion 12 170212 lon 1 26158832 rad 3 2 Main program for
213. rcumstances When connecting the A3LA to a personal computer the 9 wire interface is probably the better solution 5 1 1 1 Using the A3LA I IRIDIUM modem For the control of the A3LA the the industry standardized basic Hayes AT command set plus a extended AT command set is used AT means Attention Code and signals the modem that one or more commands are to follow Both types of commands have different syntax to query and adjust their settings As these commands are industry standard language to communicate with a modem it is used with most modems available on the market All commands in this language must begin with the characters AT The only exceptions are the repeat command A and the escape sequence Many of the basic commands consist of one single alpha character in other cases a special character like or precedes the alpha character Most of the extended commands use a prefix plus alpha characters For example Extended Cellular Commands C prefix Used for GSM cellular phone like functions Standards ETSI specifications GSM 07 07 Extended Data Compression Commands D prefix Used for data compression Standard V 25ter 5 1 IRIDIUM Communication 73 Extended Generic Commands G prefix Used for generic DCE issues such as identities and capabilities Standard V 25ter Extended Interface Control Commands I prefix Used to control the DTE interface Standard V 25ter Motorola Satellite Prod
214. rds int motor speed EndHeader START FUNCTION DESCRIPTION Ck CC Ck Ck Ck Ck C CK CI CI CI I C C x Kk Kk AA AAA int motor speed increment int slower forwards int motor speed lt drive lib gt SYNTAX int slower forwards int motor speed 4 DESCRIPTION slows down the robot 5 percent for hitting the key s PARAMETER1 None RETURN VALUE None KEY WORDS drive END DESCRIPTION OKCKCKCKCkCkCk ck kCk Ck kCk Ck kc k Ck kck k k ck kck ck kck ck ckok ck kok kok ke ke e x kx int slower forwards int motor speed int motor speed increment D 2 drive lib 175 LILLA if motor_speed 0 gt motor speed increment 100 if all motors are fa amp amp motor speed 1 gt motor speed increment 100 amp amp motor speed 2 gt motor speed increment 100 amp amp motor speed 3 gt motor speed increment 100 motor speed 0 motor speed increment set motor speeds limi motor speed 1 motor speed increment motor speed 2 motor speed increment motor speed 3 motor speed increment UpdateMotorOutput update DAC return motor speed end if end function U TL TT BeginHeader turn right qp turn right int motor speed int angle EndHeader START FUNCTION DESCRIPTION ACKkCkCk ck ck ck ck kck ck k ck ck k ck ck kk ck k k ck k k kkk k turn right int motor speed int
215. reported by a GPS receiver use the gps get position function below to set the fields typedef struct int lat_degrees int lon_degrees float lat_minutes float lon_minutes char lat_direction char lon_direction char sog speed over ground float tog track over ground GPSPosition in km define GPS EARTH RADIUS 6356 in km define dbp 0 25 distance to next basing point in km EndHeader BeginHeader gps parse coordinate int gps parse coordinate char coord int degrees float minutes EndHeader D 3 gps lib 190 nelper function for splitting xxxxx xxxx into degrees and minutes returns 0 if succeeded nodebug int gps_parse_coordinate char coord int degrees float minutes auto char decimal point auto char temp auto char dummy decimal point strchr coord if decimal point NULL return 1 temp decimal point 2 decimal point 2 0 temporary terminator degrees atoi coord decimal point 2 temp reinstate character minutes strtod decimal point 2 amp dummy return 0 BeginHeader gps_get_position int gps_get_positio EndHeader n GPSPosition newpos char sentence START FUNCTION DESCRIPTION CKCkCk ck kCk ck HK A K A k ck ck A X KA k ck ck k ck ck k ck ck ck k KKK KKK k kk kk gps g SYNTA KEYWO DESCR This GPS s PARA
216. rom it command mode to the data mode The cmd prompt will no longer be displayed and every typed input will be sent to the remote station if carriage return is hit Furthermore every incoming data will be displayed immediately To switch back and forth between command mode and data mode pressing Ctrl c keys at once can be used For example to end a active connection in data mode you must switch to command mode and type disconnect CR or short d CR The remote station will be announced of the termination of the connection and a DISCON NECTED message will be displayed in the Hyperterminal window During an active connection all kinds of data can be passed on to the KPC3plus to be sent to the remote station In our case almost all transmitted data consists of simple ASCII strings as commands or data input for Cool Robot Not only short text messages but also files can be sent trough Hyperterminal by selecting Transfer option and Send File This enables us to send longer sets of data like a bunch of waypoints without typing them over and over again but store them in a ASCII text file and send them by only two mouse clicks The KPC3 is able to send data packets of a size from 1 Byte to 256 Bytes Larger input data is divided into the needed number of 256Bytes packets Every single packet consists of an address header a control part the data itself and a checksum as shown in Figure 5 18 Single character for
217. rror handling is pretty easy with those functions since all of them return integer values that indicate whether the operation was successful or not Those return codes can be stored to a arbitrary integer variable and checked using an if statement rc fopen rd amp testfile TEST FILE NAME if rc 0 else If testfile was opened successfully rc will hold a zero and the code within the if statement will be executed Otherwise the code within the else statement maybe some error handling or just a prompt that an error occured will be executed For further possibilities on using DynamicC s flash file system the DynamicC user manual chapter 11 is recommended as well as the DynamicC function reference for more detailed information on all available functions 6 2 The Campbell CR5000 and CR1000 dataloggers All the digital data produced by the Jackrabbit s control algorithm is not supposed to be stored on a datalogger during the ongoing test runs for two reasons first the CR1000 datalogger which is supposed to be used has only just arrived and has not been tested in any way And second is the difficulty in communicating between Jackrabbit micro controller and available CR5000 datalogger Both units have the ability to exchange data via a RS232 serial port but the problem is it is unknown how the datalogger communicates exactly and what kind of commands are needed to control it There is software provided with t
218. s 135 8 1 GPS waypoint following position and navigation data 135 8 1 1 Autonomous waypoint following at fullspeed 136 8 2 Overall energy consumption on snow lt e 143 8 3 Rolling resistance LA cus Load bette thee bee eee dux gd 144 8 4 Radio Interface and Communication ls 145 A Functions and library overview 149 A l Overview of parameters and variables 151 B GPS position and waypoint following test data 155 C Schematics overview 162 D Source codes 166 pl aualogurhb sissy de ody oba de eS RS RARUS HUE vites evita 166 D ive lib aec Se 50 de 5s dne Gets Me Se See Be Gp nts Bos Hs De eke a ks 173 DE gps HD tat ec ue Aout te woe e e at e eb ees re ee E eee 189 DA navivate lib 2x aee A ADOOS XO CDL SC OU ACQUE dU A AUR 201 D 5 radiocomm elib uuu ERR ed kem B RR des 8 e 210 Bibliography 216 LIST OF FIGURES v List of Figures 1 1 Satellite Photo of Antarctica Lever llle 1 1 2 CoolRobot climbing sastrugi feature lll 1 3 Sastrugie features in Antarctica with 8 inch notebook for scaling 6 2 Milled honeycomb getting bonded and putin place 2 2 Inserts WILEY us un d ae 29 de 7 0 07 R0 ERE o e oe M bot died les 9 2 3 Chassis without and with partition wall lt lt lt lt 10 2 4 Top view of the support tube mounts and view along one of the axles 10 2 5 The aluminum shaft collars 2 xx Go Ede sexo
219. s OFF cmd Figure 5 16 ECHO ON OFF command using Hyperterminal After connecting the radio modems to their terminals and transceivers and setting them up properly establishing a wireless connection is quiet easy By just typing connect lt callsign gt lt CR gt after the cmd prompt the KPC3plus tries to connect to another packet radio station with the specified callsign The KPC is sending out a request for connection nine times ap proximately every 5 seconds If it isn t receiving an acknowledgment to its request after nine attempts it determines no station with this callsign is near and prints retry count exceeded DISCONNECTED If there is another station with the desired callsign near this station will respond to the request and determine it is connected to the host sending the request If the requesting station receives this acknowledgment it also spots the connection and prints CONNECTED to lt callsign gt 3000 HyperTerminal File Edit View Call Transfer Help joe 8 28 KANTRONICS KPC3PMX VERSION 9 0N C COPYRIGHT 2002 2003 BY KANTRONICS INC ALL RIGHTS RESERVED DUPLICATION PROHIBITED WITHOUT PERMISSION OF KANTRONICS cmd connect mahony cmd retry count exceeded xxx DISCONNECTED cmd connect mahony cmd CONNECTED to MAHONY Figure 5 17 Unsuccessful and successful attempt to connect 5 2 Radio Communication 91 As soon as successful connection is detected the modem switches f
220. s were lt 1000 m see Table 8 2 The error here was that the basing point was calculated from the current point which was within the range of the waypoint but with the distance and the bearing between the waypoints so the basing point is calculated with a small offset which has been corrected However there is again no effect on the navigation of the Cool Robot because 8 1 GPS waypoint following position and navigation data 141 it heads to the waypoint as it has a higher priority Comparing the two tests I had a close look at the bearings and the course corrections the Cool Robot had to perform off bearing 22 mar samples 25 Figure 8 4 Off bearing with basing points every 100 m off bearing 24 mar off bearing 180 160 140 120 100 80 60 40 20 0 0 20 40 60 80 100 samples Figure 8 5 Off bearing with basing points every 500 m In Figure 8 5 the three 90 degrees course changes after heading to a new waypoint are rep resented by the the peaks in the graph It takes one course correction to get back on the new desired course and the off bearing stays within a range of 20 degrees Figure 8 4 shows 8 1 GPS waypoint following position and navigation data 142 the two loops but the peaks from activating the next waypoint are not evident It is obvious that the Cool Robot does make more course corrections if generating basing points every 100 m than every 500 m It starts with a distance of a
221. s with a high efficency helps CoolRobot to be an alternative solution for heavy and expensive robots such as NOMAD for example Figure 2 1 Milled honeycomb getting bonded and put in place The structure of the honeycomb allows to mill just the fiberglass layer on one side to fold or bend the panel perpendicular When got into the project almost all parts for the honey comb chassis where already cut and milled by Alex Streeter and Alex Price Some of the aluminum parts for the drive train where also available like the wheels axles and the retainers for the motors and gear heads Thus our task was finishing the remaining parts and putting them together to a rolling chassis The first step was the gluing of the chassis body Before actually gluing it together we had to drill holes for the support tubes and the inserts for mounting the motors and the top lid since it is easier much easier to do this as while the body still is a flat piece of honey comb instead of an upright box Figure 2 2 shows the process of ap plying epoxy to an insert prior to securing the fastener to the chassis Furthermore pieces of an gle aluminum must be cut into length and sand Figure 2 2 Inserts with epoxy blasted The angle aluminum is used to reinforce the corners of the folded body sandblasting them is necessary to roughen the surface and guarantee a good bond between aluminum and hon eycomb By the way the contact surface of all a
222. seconds Defined to achieve a higher precision on reaching one exact point default 10 turn_lim navigate lib An integer that limits the maximum turning angle for one navigation cycle in degrees Makes the open loop course correction possible and is used to adjust the shifts in heading caused by sastrugi fields default 90 wp_range navigate lib A float to set the radius for the circle around a waypoint Once within that range the next waypoint is activated and the Cool Robot will continue navigating The range is the value in km default 0 030 zero_output drive lib Constant integer to set the zero output value of the DAC s Zero volts output correspond with no revolutions of the motors default 2048 155 Appendix B GPS position and waypoint following test data Table B 1 shows the data string sent back from the Cool Robot on march 24 For the abbrevi ations in the table see Table 5 14 aw aw cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl aw cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl cpl KRRR RA RRRARARAR 337 8985 4338 1 337 9045 337 914 337 921 337 933 4 1 1 337 9425 337 9486 337 9596 337 966 4 337 9762 337 9888 337 9965 338 01 338 019 4338 03 338 04 338 05 338 060 338 072 338 08 338 092 4337 92 338 09 338 083
223. sing number 1 second flash by default LX_2_USE Sets the logic extend LX to be used for the file system It is set to 1 by the function get flash Is max output drive lib Constant integer to set the maximum output varriation default 2 1220 The top speed for the Cool Robot is reached with an output voltage of 3 volts The corresponding integer value to be sent out on serial port D is zero output max output 2048 1220 3208 motor speed increment main prog Constant integer to set the difference in accelerating or slowing down for manual drive mode in percent default 10 MY LS SIZE Defined on beginning of the main program This parameter set the logical sector size of the file system as log base2 of the desired size It affects the efficiency of the file system is set to 9 which equals 1024byte the value that achieves maximum efficiency scale motor analogin lib A float to convert the 12 bit output value to motor current Channel 0 1 2 and 3 are converted A 1 Overview of parameters and variables 153 to motor current A B C and D The input range is 5 volts and 1 V output voltage 2A motor current default 5 4096 0 2 scale_tilt analogin lib A float to convert the 12 bit output value to tilt roll and pitch Channel 8 is roll and channel 9 is pitch The input range is 5 volts and 1V 1g The tilt angle is the asin from the output voltage default 5 4096 0 scale_velocity analogi
224. sistance and the surface rolling resistance With a total weight of 82 Ibs it is Frou Rr Fr 5 83 N 51 660 N 57 49 N 8 4 Guido and Gunnar measured a no load current for a single motor of 0 272 A which accounts for 1 088 ampere of the high centered current 4 With the 1 151 ampere I measured on the box the bearing losses are calculated as Lj un Tas oa Does A T lona 100 5 47 96 8 5 of the internal resistance which is great 8 4 Radio Interface and Communication To sum up to the overall performance of the actual radio communication system it is running well In all different variants of the CoolRobots main program the radio connection is one major part and it is performing absolutely trouble free especially using the new ICOM 4088 radio When running the system with the older cheaper Cobra radios we encountered some 8 4 Radio Interface and Communication 146 problems with the reliability of the system Major issues were bad connections within the microphone and speaker jacks of the Cobra radios as well as a low transmission quality and therefore a fairly short range of operation Especially when the batteries of the radios were low problems occurred because the radios did not stop to broadcast and even though the push to talk was released by the radio modems they went on broadcasting This effect jammed the radio connection and data could not be sent any more The first tests on Mascoma Lake showed th
225. start t t end if dist to wp gps ground distance amp curr pl amp active wp bearing to wp gps bearing amp curr pl amp active wp dist to wp dist to basep gps ground distance amp curr pl amp basing p bearing to bp gps bearing amp curr pl amp basing p dist to basep curr dist gps ground distance amp curr p2 amp curr pl curr bearing gps bearing amp curr p2 amp curr pl curr dist Sprintf out string aw d f c d f c bp d f c ad f c cpl d f c d f c cp2 d f c d f c dw Sf bw f dbp f bbp f cd f cb fNn Nr D 4 navigate lib 204 active_wp lat_degrees active_wp lat_minutes active_wp lat_direction active_wp lon_degrees active_wp lon_minutes active_wp lon_direction basing_p lat_degrees basing_p lat_minutes basing_p lat_direction basing_p lon_degrees basing_p lon_minutes basing_p lon_direction curr_pl lat_degrees curr_pl lat_minutes curr pl lat direction curr_pl lon_degrees curr pl lon minutes curr pl lon direction curr p2 lat degrees curr p2 lat minutes curr p2 lat direction curr p2 lon degrees curr p2 lon minutes curr p2 lon direction dist to wp bearing to wp dist to basep bearing to bp curr dist curr bearing fopen wr amp logfile LOG FILE NAME fwrite amp logfile out string strlen out string fclose amp logfile printf sNn out string send event 5 if dist to wp
226. station which sent the packet whether it received the packet correctly or not If the packet wasn t received correct or there is no answer at all after approximately 3 seconds the packet will be sent again After 20 unsuccessful attempts to send a packet the modem determines the connection as lost and prints a DISCONNECTED message to the attached computer If this happens either the remote station is out of range or it isn t broadcasting any longer This is basically what is needed to use the KPC3plus radio modem to controll Cool Robot remotely either for driving it manually get information on the robots condition or send new commands or waypoints 5 3 Controling the CoolRobot via radio link One major goal of my work was the ability to control Cool Robot remotely This includes remote manual driving of the robot as well as getting information about the robots status without having a personal computer attached to it by wire This feature is quite important for serious testing with the robot since it is important to know what is going on with the control and navigation algorithm of the robot Obviously it is very inefficient and also inconvenient walking next to the robot holding a laptop and observe the robots behavior especially in fairly cold and windy weather conditions The idea is to be able to observe and controll the robot 5 3 Controling the CoolRobot via radio link 93 from a car waiting in some distance or maybe follow the rob
227. t The motor velocity output is 1V for 120Hz Hall frequency and the tilt output is 1V for 1g The final output values are given below motor current A aw 2 iniu A motor velocity RPM qs 99 int RPM 3 16 tilt angle ax iNtvalue Used in the interrupt function are the output 0 to output 3 for the motor currents output 4 to output 7 for the motor velocities and output 8 and output 9 for the tilt pitch and roll 3 3 6 Sensor interrupts One of the two different interrupts in the drive mode wp follow full and wp follow partial are the sensor interrupts A sensor interrupt is a jump out of the current drive mode to the manual operator mode or the high centered drive mode for example A sensor interrupt is pro duced when the range of a sensor is exceeded and the mobility of the Cool Robot is no longer guaranteed 3 3 Analog sensors 49 The sensors of the robot are its eyes and all the senses it has Two different functions are programed for the sensor range handling 1 sensor high centered int tm hc int wheel air 2 sensor range Table 3 9 Sensor range handling functions Every sensor is read once every second The tilt sensors for roll and pitch are compared to a limit of the value of tilt lim If the absolute value for one of the tilt sensors exceeds 45 degrees for example the function stops the robot A routine to drive the robot back on the driven track is called The
228. t 8 tilt hc 1 output 9 tm hc wheel air i return 0 end if end for end else end function BeginHeader endif EndHeader D 2 drive lib 173 D 2 drive lib BeginHeader ifndef DRIVE LIB define DRIVE LIB EndHeader Lr START LIBRARY DESCRIPTION KKEKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK 17mar2005 drive lib Goetz Dietrich 2005 switched motor speed 0 with motor speed 2 got stuck not really implemented because no adc available backup tilt implemented functions to drive the robot in the wanted direction faster forwards slower forwards turn right turn left stop SwapBytes SendToDAC UpdateMotorOutput DispStr forward_full forward_partial backwards_tilt manual_drive wp follow full wp follow partial high centered END DESCRIPTION OKCKCKCKCKCKCkCk I Koko kok k kok Kk I kCk Ck k Ck k k ck kck ck kok ck ck ck ck ckck ck ko x k BeginHeader define SPI SER D Definition of the output channels define DACA 0x1000 12 bit control register filled up with zeros 0001 define DACB 0x5000 0101 xxxx XXXX XXXX is DACB define DACC 0x9000 1001 xxxx XXXX XXXX is DACC define DACD 0xD000 1101 xxxx xxxx XXXX define Akey 65 define DownArrow 25 const int zero output 2048 0 volts output const int max output 1220 1220 3
229. t dist to basep extern float curr dist extern float initial bearing extern float bearing to wp extern float bearing to bp extern float curr bearing extern float off bearing extern float off track extern float alpha used for the off track calculation extern int wp active extern int motor speed 4 extern char key input extern char out string 256 extern char in stri D 4 navigate lib 202 extern int send event extern int wp start extern int wp count extern int dist bpdiv extern int GPS inv limit extern File logfile EndHeader GPSPosition start p GPSPosition curr pl GPSPosition curr_p2 GPSPosition active wp GPSPosition last wp GPSPosition basing p Er oat initial dist loat dist to wp loat curr dist oat initial beari loat curr bearing loat off bearing loat off track loat alpha loat dist bp int dist bpdiv Fh Fh Fh Fh Fh Fh Fh Fh Fh Fh Fh Fh loat dist to basep ng loat bearing to wp loat bearing to bp used for the off track calculation START FUNCTION D navigate navigat e lib SYNTAX void navigate ESCRIPTION ACkCkCk ck ckCk ck kCk ck k ck ck kc kck A X KZ ck k ck ck k ck ck ck k ck ck k ck ck ck ck ck A ck ck HK k kk kk DESCRIPTION basic navigation needs for CRobot to head to the next waypoint PARAMETER1 active wp is position of waypoint in array w
230. t is following waypoints We wanted to be able to record the navigation data without the need for a radio link Furthermore the file system offers the possibility to log all other relevant data produced while CoolRobot is operating like currents wheel speeds tilt angles and so on once the ADC is running To keep all the collected data more concise and make the analysis easier different kinds of data can be stored to different logfiles At the moment there is only one logfile used to record the navigation data but as soon as the the new 6 1 Storage and retrieval of internal sensor data 107 analog to digital converter is running there will be a demand to record motor currents while the robot is running around It would be easy to create a second logfile for all kinds of current and voltage readings by just duplicating and slightly modifying existing code Instructions for setting up a file system in the flash memory using DynamicC are described in detail in chapter 7 1 and 7 2 For the basic file related tasks like reading from the file and writing data to it some functions provided by DynamicC s library FS2 LIB are essential fopen_rd File FileNumber fopen_wr File FileNumber simply opens the specified file either in read mode fopen rd or write mode fopen wr A file cannot be opened for both reading and writing at the same time fseek File Where Whence is used to set the current read write position of the file The
231. t of the robot the decision was made that an IRIDIUM modem shall be use for the data communication in the Antarctic Iridium is a global satellite based cell phone technology At the moment IRIDIUM is the only provider of satellite voice and data solutions with coverage of nearly the whole surface of the earth including all oceans airways and also the arctic and Antarctic region Due to the long distances of several hundred kilometers the robot is covering IRIDIUM is the only way to stay in touch with Cool Robot Since Cool Robot is a lightweight construction there is no possibility to use big heavy radios with the range needed in this application Another argument for not using such a radio is the power consumption and power output since this may affect the electronics controlling the robot and also the measurements of the carried payload The big advantage of IRIDIUM technology is its global availability and the fact that it makes no difference if the operator is also in the Antarctic or somewhere else in the world The disadvantage is the high price and slow bandwidth of 2400Bit s According to this there will be no permanent connection but rather only data transfer when needed Therefore either the robot or the operator will have to establish the connection Figure 5 1 provides an example IRIDIUM application 5 1 IRIDIUM Communication 69 BY ad Antenna K lt i a f 9522 LBT i Aoplication Nicrocontroler gt
232. tal planes each with 4 satellites equally spaced around the equator and inclined at 55 degrees The GPS receiver on earth determines position by passive multi lateration With knowledge of the transmission time for each signal the distance to each satellite with known coordinates in space can be calculated To determine the correct 3 dimensional position latitude longitude and altitude the receiver needs the clock offset Therefore a minimum of four satellite observations are required to mathematically solve for the four unknown receiver parameters If the altitude is known then only three satellite observations are required However that is not a guarantee for consistent accuracy The accuracy depends on the number of satellites tracked With 5 or more satellites the receiver s position can be accurate up to a few meter Figure 3 3 The accuracy can be increased up to less than 1 meter with Differential GPS DGPS Hereby the receiver s signal is corrected with a second GPS signal send out by a stationary GPS receiver on Earth The correction signal is sent in a longwave signal The correction stations are generally provided in coastal regions and driven by the coast guard CoolRobot will have a DGPS receiver for the testing in Greenland but for the navigation during this thesis it is equipped with a Motorola Oncore M12 receiver see chapter 3 1 1 Figure 3 3 shows some driven tracks against the background of the j parking lot on Dartmouth
233. tence marked invalid SEE ALSO nodebug int gps get utc struct tm newtime int i char temp str 3 unsigned long epoch sec temp str 2 0 2 character string if strncmp sentence SGPRMC 6 parse RMC sentence for i 0 i lt 11 i sentence strchr sentence if sentence NULL return 1 sentence first character in field pull out data if i 0 strncpy temp str sentence 2 0 newtime tm hour atoi temp str strncpy temp str sentence 2 2 newtime tm min atoi temp str strncpy temp str sentencet4 2 newtime gt tm sec atoi temp str if i 1 link quality if sentence A return 2 if i 8 lon direction strncpy temp str sentence 2 newtime tm mday atoi temp str char sentence ESCRIPTION Parses an RMC sentence to extract time data PARAMETER1 newtime tm structure to fill with new UTC time PARAMETER2 sentence a string containing a line of GPS data END DESCRIPTION OKCKCKCKCkCkCkCk kCK Ck kCKCkCkCKCkCkCKCkCkCKCkCkCKCKCkCKCkCkCK Ck kCk k kc k kck ck kck ck ck ok ck K kk ck ck ck ko ke ke x char sentence D 3 gps lib 195 strncpy temp str sentence 2 2 newtime tm mon atoi temp str strncpy temp str sentencet4 2 newtime tm year 100 atoi temp str convert back and forth to get weekday epoch sec mktime newtime mktm newtime epoch s
234. termination to AGND at the AinO to Ain15 sockets S0 S15 LK16 LK17 LK18 LK19 S17 S18 S19 left unconnected Allows to user to connect a particular AD713 op amp input to ground H In position C an external VDRIVE supply voltage must be supplied via J7 In position A the AD780 provides the 2 5V reference to the AD7490 Adds a 50 termination to AGND at the Vin input to the Bias up circuit unconnected This link option selects the source of the SCLK input In position J2 the 12V is supplied from an external source via connector J3 In position J3 the 12V is supplied from an external source via connector J3 In position J2 the AVDD is supplied from an external source via connector J2 Table 3 8 Switch and link options on EVAL AD7490CB 3 3 2 12 bit 16 channel Analog to Digital Converter on serial port B When setup as described in chapter 3 3 1 the AD7490 can be accessed trough serial port B using SPI 3 3 Analog sensors 40 SPI is a three or four wire connection to shift data between two parts like a microcontroller and an analog to digital converter There are two connections for data input and data output and then one for chip select and one for the serial clock A data word transmission is started by generating a falling edge on the chip select line C S The following defined number of bits are send with the falling edge of the serial clock SCLK After the transmission CS is pulled high again to end the dat
235. th the five keys w a s d q w All four motor speeds are increased by the value of motor_speed_increment which is 10 in default as long as none of the four already is at full positive speed If the robot is driving backwards an increase of the nagative value will force it to go slower backwards If the commands are sent through the radio connection more then one key can be sent at one time A string of ten times w should be avoided since the stress on the motor the gearhead 4 4 The different drive modes of Cool Robot 63 the support tubes and the axes is very high then because there is almost no delay between the commands S All four motor speeds are decreased by the value of motor speed increment as long as none of the motor speeds already is at full negative speed If driving forward the robot is decelerated 10 angle 2 and motor a By sending the key a the motor speed A and motor speed B are decreased angle speed C and motor speed D are increased 75 The variable angle defines the radius for a turn if a was sent once As the robot is skid steered it can turn on one place by driving one side of the wheels at 100 positive speed and the other at 100 negative speed If the robot is driving forward it will make a left turn with the key a but if the robot is driving backwards it will make a right turn as the direction of front changes d The command d makes a right turn instead of a
236. the active waypoint in kilometers bw contains the current bearing to the active waypoint in degrees dbp contains the distance to the active basing point in km bbp contains the current bearing to the active basing point cd means current distance traveled since programm start cb means current bearing clockwise counted from north Table 5 14 Components of navigation data string Such a set of data 1s approximately 235 characters long which equals 235 Bytes Since the maximum amount of data the modems can handle in one data packet is 256 bytes each of 5 3 Controling the CoolRobot via radio link 98 those data sets fits within one packet and the transmission takes round about 2 seconds The robot is sending this data once after every completed run through the navigation algorithm Since it takes something between 5 and 20 seconds for one complete navigation step including the turn the robot takes for its course correction there is enough time to send data packets of this size once every step 5 3 4 Other commands and functions Irrespective of the drive mode there is always the possibility to send new waypoints to the robot or request its current status or some of the stored data One of the most important features within the communication topic is transmitting new waypoints to the robot and by determining the robot s future route To send the robot one or more new waypoints a simple string must be send containing the number of wa
237. the next 15 seconds and determines current position 1 and the current bearing for the last 15 seconds After completing the second course correction the off bearing for the next navigation cycle is at 25 Due to the demanding terrain the robot could not drive straight ahead So the next course correction is 23 After four course corrections the off bearing is within a 10 range and the robot will not make any further major corrections 8 1 GPS waypoint following position and navigation data 140 Figure 8 3 Waypoint and basing point shifting sample Figure 8 3 shows an example waypoint shift from the test The robot travels on the path fol lowing the basing point As the last basing point is the waypoint the algorithm recognizes that and heads for the waypoint instead of the basing point As the range for generating the next basing point is larger than the range for activating the next waypoint the algorithm generates one basing point more in the direction of the last waypoint but does not head towards it The next test shown in Figure B 2 was made with some different parameters set as shown in Table 8 3 wp range 0 030 bp range 0 045 tm nav 15 dis bp 0 5 Table 8 3 Parameters for waypoint following at full speed 24 mar The generated basing points coincide with the waypoints because the calculation of the dis tance between basing points was set to 500 m and the distances between the waypoint
238. the program will be terminated with exit code 2 7 2 Start up sequence initializing of variables file system and serial ports 122 FSrc fs_init 0 0 if FSrc printf Could not initialize filesystem error number d n errno exit 2 After the successful initialization the file system can be formated using Ix format LXnum wearlevel or an existing file system can be reused If any error occures the program will be terminated with exit code 3 If no errors occur the memory of the logic extend is printed printf Do you want to n printf enter Re use existing filesystem or n printf F enter Format the filesystem LX n gets buf if toupper buf 0 F FSrc lx format LX 2 USE 0 if FSrc printf Format failed error code d n errno exit 3 printf Capacity of LX d is approximately ld bytes n int LX 2 USE fs_get_lx_size LX_2_USE 0 0 The last step is to create a file using function fcreate File FileNumber If the error File exists is returned the program will ask the user whether the old file should be deleted and a new file created or if the old file should be kept and the new data appended to the existing file In case of appending the new data to the existing file the program will ask for a separator which makes it easier to distinguish data of different test runs from each other fs set Ix LX 2 USE LX 2 USE FSrc f
239. to calculate the bearing between two gps positions gps bearing had to also be transformed for a use with the double precision structure and can be found in the gps lib It returns the bearing in true degrees I took the formula to calculate the bearing with knowledge of the distance between two points a and b sin laty sin lat cos dist sin dist cos lat 3 9 bearing arccos and converted it to use double precision see chapter 3 2 3 The arccos was substituted again with equation 3 7 The navigation algorithm calculates different kinds of bearings The initial bearing is the bear ing between two waypoints and marks the desired track for the CoolRobot Initial distance and initial bearing do not change unless the robot reaches the waypoint and heads to the next way point The bearing to waypoint bearing to wp is the bearing from the current position of the robot to the active waypoint same as the bearing to basing point bearing to bp is the bearing from the current position to the basing point These bearings and the appropriate distances change between two navigation cycles and are used to calculate the off bearing by taking the difference to the current bearing curr bearing bearing to wp curr bearing for dist to wp lt dist to bp off bearing 3 10 bearing to bp curr bearing for dist to wp gt dist to bp The range for the off bearing is 180 lt x lt 180 whereas a negat
240. tring GPS sentence invalid n r send_event 5 end else if if count_invalid GPS_inv_limit drive_mode 5 return 0 end if end costate end while end if end else if return 2 end function BeginHeader turn_full turn_full float off bearing analogin lib EndHeader TART FUNCTION DESCRIPTION KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK k kk KKK turn_full off_bearing lt navigate lib gt SYNTAX void turn full float off bearing DESCRIPTION makes a turn of off bearing degrees to right off bearing gt 0 or left off bearing 0 PARAMETER1 calculated off bearing from initial course to waypoint RETURN VALUE None KEY WORDS END DESCRIPTION OKCKCKCKCkCkCk ck kCk Ck kCk Ck kc k k kck k kk kck ck kok ck ckok ck ckok ck ko kk ke e x kx void turn full float off bearing D 4 navigate lib 207 auto int i long turning_tm i 1 if off_bearing lt 0 turning tm int off bearing 300 motor speed 2 90 motor speeds are set to 100 motor speed 1 90 UpdateMotorOutput while i 1 costate waitfor DelayMs 1000 read sensors interrupts end costate costate waitfor DelayMs turning tm motor speed 2 100 motor speed 1 100 UpdateMotorOutput i 0 end costate end while end if else if off bearing gt 0 turning_tm in motor
241. trol it if necessary through the radio communication This chapter describes the testing itself The necessary preparations the startup routine and especially the reading and interpretation of the feedback data will be discussed 8 1 1 Autonomous waypoint following at full speed The robot is transported without any power supply Once at the testing area the batteries and the main housekeeping power distribution board are connected first Then the jackrabbit the GPS receiver and the modem are connected Before suppling the DAC make sure the output channels are not connected to the motor controllers because they are at 2 9 V if they were shut off from power The main program may be compiled to the jackrabbit at that point The motor 8 1 GPS waypoint following position and navigation data 137 speeds are set to zero and are connected to the motor controllers If both modems are powered up they will connect autonomously The connection to the jackrabbit is closed and the modem is connected to the serial port or an alternative port e g USB and accessed through Hyper Terminal see chapter 5 3 3 The robot can now be controlled through the keypad as it is in drive mode manual operator To switch to waypoint following drive mode the motor speeds must be set to zero and p has to be hit Cool Robot now starts to navigate as described in chapter 4 4 1 Figure B 1 shows a picture of the data evaluation with excel The test consists of
242. ts are the digital value of the analog input voltage The SPI port reads the 16 bit data word 3 3 Analog sensors 44 as two complete bytes which are shifted into a two dimensional character array data 2 A bitwise and is performed with the first byte and OF to extract the four address bits 0000 1111 amp 0101 0011 0000 0011 3 11 The first four bits of the digital conversion result remain unchanged At first I thought about programming a checksum for the address bits to guarantee a reading on the correct channel but then decided to keep it simple and the communication through the serial port is correct 3 3 3 Dual axis accelerometer used as a tilt sensor The dual axis tilt sensor is a dual axis accelerometer ADXL203 from Analog Devices The ADXL203 measures acceleration with a full scale range of 1 7g The ADXL203 can be either used to measure dynamic or static acceleration e g gravity By mounting different capacitorsC and Cyto the Xo and Yout pins the user selects a bandwith between 0 5 Hz and 2 5 kHz of the accelerometers The part is temperature rated from 40 C to 125 C With a 5V supply voltage the accelerometers have a sensitivity of 1000777 The five extremal positions are listed and shown below a up x 2 5V y1 2 5V x2 20V y2 1 5V 3 3 Analog sensors 45 o woh dn d top front e bottom front Ly 2 5V sy 1 5V T2 2 5V Y2 2 5V The acceler
243. two loops following the four waypoints The parameters for the navigation algorithm were set to wp range 0 025 bp range 0 030 tm nav 15 dis bp 0 1 Table 8 1 Parameters for waypoint following at full speed 22 mar The Cool Robot had connection to the laptop via radio communication The data string sent back to the user after completion of a navigation cycle consists the active waypoint the bas ing point headed to the current points and information about all the different distances and bearings Logged as one string for each cycle in the editor the data can be imported in excel easily by dividing the different values with a and a To graph the position data in a diagram the longitude and latitude have to be converted This means if the latitude direction is S or the longitude direction is W the value has to be multiplied by 1 Another fact that has to be taken into account is that each position data from the jackrabbit is of the structure GPSPosition The degrees are an integer value and the minutes are a float value If the min utes are lt 9 dynamic C is not able to display the leading zero and appends the second digit directly onto the integer degree A longitude of 7209 3600 W ddmm mmmm for example is displayed as 729 3600 The sample test for Figure B 1was taken on March 22nd on lake mascoma Two different loops were performed to compare the track from the first to the second run The
244. uct Proprietary Commands MS prefix Proprietary to the Motorola Satellite Series product line Both the command prefix AT as well as the command sequence itself can be typed in upper or lower case but must not be a mix of both Furthermore many commands can be typed within one command line divided by spaces for better reading if desired Figures 5 5 and 5 6 show example commands and command lines ATXO set basic command ATXn to n 0 AT amp V execute basic command AT amp V AT GSN execute extended command AT GSN AT CBC query the valid range of responses of extended command AT CBC AT CPBR 1 12 execute extended command AT CPBR with parameters 1 and 12 AT MSVLS query the current setting of extended command AT MSVLS Figure 5 5 Some sample commands with explanation AT manual for A3LA at x 0 av gsn cbc cpbr 1 12 msvls all lower case AT X 0 amp V GSN CBC CPBR 1 12 MSVLS all upper case ATX 0 amp V GSN CBC CPBR 1 12 MSVLS space omitted between AT and X ATX0 amp V GSN CBC CPBR 1 12 MSVLS space omitted between ATX and 0 ATX amp V GSN CBC CPBR 1 12 MSVLS 0 omitted from ATX0 ATX amp V GSN CBC CPBR 1 12 MSVLS semicolon separators ATX amp V GSN CBC CPBR 1 12 MSVLS no separators Figure 5 6 Example for different ways to type commands AT manual for A3LA The only limit hereby is the size of the command line buffer which normally accepts 39 characters i
245. ues for the ResultCode Table The Table parameter is the data table from which record s should be transmitted 6 2 The Campbell CR5000 and CR1000 dataloggers 113 TableOption determines which records should be sent from the data table 0 send all records since last execution 1 send only the most recent record stored in the table BufferControl is used to specify whether the ramdom or self timed buffer should be used and whether data should be overwritten or appended to the existing data The data stored in the self timed buffer is will be transmitted at a predetermined time frame only and the data is erased from the transmitter buffer after each transmission Data in the random buffer is transmitted immediately after a threshold has been exceeded and the trans mission will be repeated randomly to insure it is received Data in the random buffer must be erased using buffer control code 9 after random transmissions are finished A numeric value is entered for this parameter Code Description Append to self timed buffer Overwrite self timed buffer Append to random buffer Overwrite random buffer NO WN E c Clear random buffer Table 6 2 Possible values for BufferControl 6 2 The Campbell CR5000 and CR1000 dataloggers 114 DataFormat is a numeric value used to define the format of the data sent to the transmitter Code Description O0 CSI FP2 data 3 bytes per data point Floating point ASCII 7 bytes per data poi
246. unts for the axle to align the motors as exact as possible and avoid unnecessary high friction within the drive train To add more strength to the partition walls angle anluminum was used to reinforce the connection on either side of the walls and on the bottom Figure 2 4 Top view of the support tube mounts and view along one of the axles 11 After that the mounts for the support tubes see figure 2 4 were glued to the chassis To assure an exact alignment of both support tubes on one axle a long piece of the aluminum tube used for the support tubes was used through the tube holes on both sides of the robot The tube remained within the axle over night until the epoxy cured up completely Since the mounts on the outside consist of two independent rings some of the epoxy could have reached the tube thus to avoid gluing the tube to the mounts we moved it from time to time In the meantime the shaft collars were milled and the inner parts of the rims were welded to the ac tual axles Furthermore all inserts were glued to the chassis and the motor and gear heads were mounted too For gluing the inserts we coated the contact areas with epoxy put both parts with a screw and nut to the desired hole and tightened Figure 2 5 The aluminum shaft the screw carefully until both parts of the inserts collars engaged The next step was finishing the support tubes and gluing them in place The tubes were cut to length and on one
247. urther settings a user can change but only one of them is off greater importance for our application Using the ECHO command one can determine whether characters sent to the modem should be echoed locally or not For use with a personal computer and terminal soft ware this is not very important since this setting can also be made within the terminal soft ware The Jackrabbit on the other hand has no need for an echoed character In fact this is actually bad for the communication routines since every incoming character string is inter preted by a function within the communication routines see chapter 7 3 2 and may cause wrong or unwanted inputs It would certainly be possible to compare everything received to what was send but this would waste scarce runtime and memory on the micro controller So the Cool Robot s modem does not echo received characters This setting is made typing ECHO lt CR gt to check whether the option is active or not and if its on one can simply type ECHO OFF lt CR gt to turn it off As matter of course the other way around typing ECHO ON lt CR gt turns character echoing on again 5 2 Radio Communication 90 KPC 3000 HyperTerminal File Edit View Call Transfer Help ID 6 DA E KANTRONICS KPC3PMX VERSION 9 0N C COPYRIGHT 2002 2003 BV KANTRONICS INC ALL RIGHTS RESERVED DUPLICATION PROHIBITED WITHOUT PERMISSION OF KANTRONICS cmd echo ECHO ON cmd echo off ECHO was ON cmd ECHO wa
248. user s guide chapter 5 For our application we decided for an output of the GPRMC message once per second GPRMC 154425 00 A 4342 5660 N 07216 9153 W 2 4 338 0 190105 28 GPRMC 154425 00 A 4342 5660 N 07216 9153 W 2 4 338 0 190105 28 Figure 3 6 GPRMC example message message header UTC time of the position fix in hours minutes and seconds current position fix status with A designating a valid position and V an invalid current latitude in degrees and minutes direction of the latitude with N indicating North and S indicating South current longitude in degrees and minutes direction of the longitude with W indicating West and E indicating East current ground speed in knots current direction referenced to true North UTC date of the position fix checksum Table 3 2 GPRMC message The M12 receiver is used with the backup battery which is not necessary but useful for sav ing setup information especially the data output format and increasing the speed of satellite acquisition and fix determination when the receiver is powered up after a period of inactiv ity Battery equipped M12 receivers are fitted with rechargeable 5 mAh cells sufficient for 2 weeks to a month of backup time depending on temperature To recharge the cell the receiver must be powered up a complete empty battery needs up to 24 hours of charge time If set to default the receiver can be configured with the software again The GP
249. volts output char key input EndHeader D 2 drive lib 174 T TL TTL LTL L L TL TT TL T BeginHeader faster forwards int faster forwards int motor speed EndHeader int motor speed increment START FUNCTION DESCRIPTION CC C CC Ck Ck CK CI CI CI I CC C C x Kk KK Kk A AA faster forwards drive lib SYNTAX void faster forwards DESCRIPTION speeds up the robot 5 percent for hitting the key w or slows down when driving backwards PARAMETER1 None RETURN VALUE None KEY WORDS drive END DESCRIPTION OKCKCKCKCkCKCk ck kCk Ck kCK Ck kc k Ck kck k k ck kck ck kck ck ckok ck kok ko ke ke ke e x kx int faster forwards int motor speed int motor speed increment if motor speed 0 lt 100 motor speed increment if all motors are abl amp amp motor speed 1 lt 100 motor speed increment amp amp motor speed 2 lt 100 motor speed increment amp amp motor speed 3 lt 100 motor speed increment motor speed motor speed increment rise them up to a 100 motor speed motor speed motor speed motor speed i motor speed i motor speed i UpdateMotorOutput ncrement ncrement ncrement sends the new value of motor sp return motor speed end if end function T TL L Mill ll P L T L L T PT Ip M MM PII gg IM BeginHeader slower forwards int slower forwa
250. will run the algo rithm for the drive mode waypoint following at full speed The variable can be changed within the algorithm of one drive mode to exit it and enter another drive mode on the next cycle or it can be changed by the function that computes the modem input if the command for certain drive mode is received For example CRCMDMANDM will set drive mode 5 and the manual drive mode will be entered on the next cycle The purpose of almost all global variables is described within a comment next to the variable in the actual code of the MAIN PROGV0 34 C 7 2 Start up sequence initializing of variables file system and serial ports The program itself starts with the void main statement and the first things we need to do before any function is called is an initialization of the variables This is necessary because with the declaration of a variable only an logical address is associated with the variable name but the actual memory at the given address is not formated so the data of an earlier program still exists and fills the variable with unknown values Therefore all variables should be set to a discrete value before they are used by any function Of special importance is for example 7 2 Start up sequence initializing of variables file system and serial ports 120 the setting of the motor speeds and the sending to the motor controllers using the function UpdateMotorOutput void main status_modem 0 wp act
251. wp range wp active if wp active wp_count 1 stops crobot last waypoint stop motor speed motor speed increment drive mode 5 return 2 end if last wp wp list wp active 1 store last waypoint active wp wp list wp active update waypoint initial dist gps ground distance amp last wp amp active wp initial bearing gps bearing amp last wp amp active wp initial dist dist to wp gps ground distance amp curr pl amp active wp bearing to wp gps bearing amp curr pl amp active wp dist to wp dist bpdiv initial dist dis bp dist bp initial dist dist bpdiv gps basing point amp last wp amp basing p initial bearing dist to basep gps ground distance amp curr pl amp basing p bearing to bp gps bearing amp curr pl amp basing p dist to basep end if else if dist_to_basep lt bp range if dist to wp gt 2 dist to basep gps basing point amp basing p amp basing p initial bearing dist to basep gps ground distance amp curr pl amp basing p bearing to bp gps bearing amp curr pl amp basing p dist to basep end if end if D 4 navigate lib 205 alpha costate end else calculation of the track offset if bearing_to_bp gt initial_bearing alpha bearing to bp initial bearing end if else alpha initial bearing bearing to bp end else
252. xiting got stuck drive_mode 1 return 1 end if while stk lt 9 costate waitfor DelayMs 100 slower forwards motor speed motor speed increment stk end costate end while stk 0 costate waitfor DelayMs 12000 D 2 drive lib 188 while stk lt 19 costate waitfor DelayMs 100 faster forwards motor speed motor speed increment stk end costate end while end costate end while end got_stuck BeginHeader fendif EndHeader D 3 gps lib 189 D 3 gps lib BeginHeader ifndef GPS LIB define GPS LIB EndHeader START LIBRARY DESCRIPTION Ck CK Ck Ck Kk Ck CK Ck Ck CK CC Ck Ck AXA A A CI X AXA Ck Ck kk KHK KA kx x ko ko ko ko 23mar2005 gps lib ZWorld 2001 Goetz Dietrich 2005 bearing calculation changed to double arccos transfered to arctan bearing calculation changed to 0 180 case functions for parsing NMEA 0183 location data from a GPS receiver Also has functions for computing distances bearings and to calculate basing points gps get position gps get utc gps ground distance gps bearing gps basing point getgps END DESCRIPTION OKCKCKCKCKCKCk Ck kCK Ck kCKCkCkCKCkCkCK Ck kCKCkCkCKCKCkCKCkCkCK Ck kCk Ck kc k k kc k kck ck kok ck ckok ck ckck sk ko x BeginHeader This structure holds geographical position as
253. ypoint in km is calculated with the function gps_ground_distance in the gps lib With the distance from startpoint to first active waypoint the bearing to that waypoint in true degrees is calculated A bearing value of 360 or 0 means the robot is heading to the geographic North Pole and 180 means the robot is pointing to the South Pole Once in Antarctica CoolRobot will have waypoints with a distance of 50 km or more To assure that the offset from the track to each waypoint does not increase beyond a limit basing points are generated in a predetermined distance to each other on the track from waypoint to waypoint The distance to basing point dist is calculated in the navigate function at startup The distance to the active waypoint is divided by 1000 m and the result is rounded off to an integer The initial distance is then divided by that integer and will give a distance between basing points close to 1000 m That calculation is made to make sure that there is a whole number of basing points between two waypoints and that the last basing point is the waypoint active waypoint initial bearing basing point 1 initial distance starting point Figure 3 9 Basingpoint and waypoint example drawing 3 2 Main program for autonomous navigation 26 The last thing done in the startup procedure is that 1 is added to wp_start so that the func tion does remember it s starting point If the navigation algorithm was called f
254. ypoints send in this packet and the waypoint data To be able to process all incoming data as fast and secure as possible I figured out that all the commands used within the data transfer except the command strings for the manual driving should have a certain structure and an equal header Since the appearance of such a header is not of significant importance I decided to use a character followed by the characters C and R as they are the initials of CoolRobot This pre header is followed by three further character which indicate what type of data follows or respectively what kind of command is received New waypoints are indicated by the characters WPT The header is then followed by a comma the number of waypoints to follow and another comma The waypoint data is subsequently attached every waypoint must be divided from the next by another comma and the waypoints must be of the following syntax ddmm mmmmLdddmm mmmmB The first 9 characters determine the latitude in degrees dd and minutes mm mmmmm and the tenth character holds the information whether the waypoint is in the northern N or southern S hemisphere It is almost the same with the longitude data three characters for degrees ddd seven characters for minutes mm mmmm and one for eastern E or western W direction Thus a full example will look like this SCRWPT 2 4338 1000N07209 1200W 4337 9200N07208 7600W 5 3 Controling the CoolRobot via radio link 99 Th

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