Final Report Outline - Electrical and Computer Engineering
Contents
1. 11 FIGURE 4 5 VOLT VOLTAGE REGULATOR 13 FIGURE 5 12 VOLT VOLTAGE REGULATOR 13 FIGURE 6 WEATHER PROGRAM LADDER LOGIC 222 202000000010000000000000000002000000 21 FIGURE 7 PLC VARIABLE MEMORY 22 FIGURE 8 INDUCTION DIR T 3l FIGURE 9 SOFT STARTER vi 31 FIGURE 10 VOLTAGE VS TIME GRAPH rrrerrrnnnnnnrnrrenreernennnnnnrnrnenssennennnnnnrsensersnenennnnrnenenssennennnnnnn 32 FIGURE 11 SOFT START WIRE DIAGRAM 2 0000000000000000000000000020000 32 FIGURE 12 HARDWARE SETUP ode suas i 34 BIGURE 13 SENSOR H use 34 FIGURE FRONT suites es 35 FIGURE 15 ERROR CORRECTION 36 FIGURE 16 ROUTINE CHECK s erooroerseseessnnnnrnensesneennnnnnnnenensseneennnnnnnnerenssessensnsnnrnensessessenennnnerensseneenen 37 FIGURE 1 7 ROTATION CODE nas titio Ana 41 FIGURE 18 SHUTTER CODE dos vse aa OTe e D 43 FIGURE 19 TELESCOPE SYSTEM BLOCK DIAGRAM 47 FIGURE 20 REMOTE HANDBOX 49 BIGURE 21 ENVISGE IMAGING tenete etit vites 49 FIGURE 22 INTERFACE FLOW DIAGRAM 51 FIGURE 23 SETTING UP LOCATION SETTINGS2. Monday March 24 2008 of 1 Figure 13 Sensor Circuit 36 5 3 2 PLC 5 3 2 1 PLC Hardware The PLC consists of several different parts For the scope of this project only the parts used will be included The main body of the PLC is the Chassis 1771 A2B This is the body of the PLC which holds all of the necessary cards The PLC is controlled by the PLC 5 25 Processor 1785 LT2 with a 1771 P4S Power Supply Inputs at transistor transistor logic TTL levels are sent into the PLC through the TTL Input 1771 TTL IGD card Outputs are controlled by the AC Output 1771 OAD C card Each card has specifications that can be found in the Appendix of this document OPERLT CONF RESULT IN AMMASLE CONTR 11 1 Figure 14 PLC Front 37 5 3 2 2 PLC System Overview The figure below depicts how the PLC is coded to operate The desired position or the telescopes position is the input to the system This position is summed with the systems output which produces the system error The error is processes and a correction signal is output through the D A Converter to the dome controls The dome controls will rotate the motor to eliminate the error of the system This process will continue until there is a minimal error within tolerance in the system Desired 1771 IL Processer 1771 OAD C Position Analog 12 bit Card Discrete Output Card N Input card y e t A
3. 1 110200000000000000000000000000 53 FIGURE 24 COM PORT SETTINGS cccessessecececcceceesenseaececececeesessasececececeesensaaeeeseeeesesesesssaeeeseceens 53 FIGURE 25 SENSOR CIRCUIT 1 12022 2 40100 00000000000000000000000000000000 00 56 FIGURE 26 SENSOR CIRCUIT BACK iei o sse i bo ee tee 56 List of Tables 1 LISTOF MATERIATS ras Pe TEE rec E E eee 10 TABLE 2 LINKS TO SENSOR MANUALS sen uiaei a 12 TABLE 3 ROTATION CODE OVERVIEW enses tenente tenete sisse senten 37 TABLE 4 SHUTTER CODE OVERVIEW 2000000000 00000000000000000050000000000 42 Abstract The goal of the Space Grant Internet Telescope Network SGITN is to make astronomical instruments available to people around the world through the internet This means that students all around the world can access telescopes all around the nation This network of telescopes will allow students to use expensive equipment without the setup cost This will also allow students in locations where sky observations are not possible to gain interest in space by a click of their mouse All telescopes are in permanent locations and using them means sitting down at an internet connected computer logging into the instrument and starting to take pictures This eliminates literally hours of set up and tear down work at the beginnin
4. Figure 26 Sensor Circuit Back 7 2 Lessons Learned Many mistakes have been made throughout the course of the semester all of which we have learned something from One of the biggest lessons learned is to keep good and detailed documentation There were a few times when already engineered information was reengineered do to a lack of documentation If documentation was concurrently produced during the engineering process it would have saved some time when that information needed to be reviewed The Latter Logic code written for the PLC just like any code has a different type of language and its fair share of quirks The hardest part about learning a new programming language is to understand how the code works and how to trouble shoot it when there is undesirable results Even with user manuals a good amount of engineering hours were dedicated to learning and producing the desired code to operate the PLC 58 The Rocky Mountain Space Grant Observatory project incorporates multiple groups all working on different parts but all of us were working towards the same goal of getting the observatory to be completely automated Communication is an essential part of a group project to ensure that all jobs are understood executed and done right Each group may be working on different part of the project but all subgroups still needed to use the same computer and work space to get their jobs done Communication was essential to ensure that everyone had
5. This sensor requires no input voltage to power the sensor it generates its own AC sine wave This however is a minor problem as the PLC cannot accept a low frequency sine wave input To convert the sine wave output to a square wave a LM358 operational amplifier and a 2N3904 BJT were used The operational amplifier is used in an inverting non linear configuration with a gain of ten The BJT is connected to the output of the op amp to generate the 5V pulse wave The PLC counts 12 the number of pulses per second frequency uses a simple equation to produce the wind speed The PLC will then close the dome when a predetermined threshold is reached see Weather Research section Below is the schematic for the sine wave to square wave circuit 18V Hin out T 12V 18 8 LM7812 pin 2 goes to ground o C1 Vin sine wave 4 TV LM7805 5V 0 pin 2 goes to ground 0 Vout square wav 10u R3 ANV 10k R6 5V in d 1V out Q1 NW 2N3904 D Figure 3 Sine Wave to Square Wave Circuit 4 1 3 HMP45C Temperature Humidity Sensor In order to protect the telescope from severe cold and for early storm detection temperature and relative humidity sensor is incorporated into the system The HMP45C Temperature Relative Humidity sensor is being used for this application The recommended input voltage to the sensor is 12VDC To power the sensor the 1
6. Anemometer Young 03101 R M 1 216 00 0 00 216 00 weather Rain Gauge Campbell 525 1 145 00 0 00 145 00 weather Snowfall Adapter Campbell CS705 1 460 00 0 00 460 00 weather 6 Tripod Campbell N A 1 420 00 0 00 420 00 weather Radiation Shield Campbell N A 1 175 00 0 00 175 00 weather Cross Arm Campbell CM 204 1 78 00 0 00 78 00 weather Campbell CM 220 1 21 00 0 00 21 00 Mount Kit weather Various N A 1 3 50 0 00 3 50 Anemometer PLC 5 25 with Donated dome mise T O Cards Allen Bradley PLC 5 25 1 Equipment dome PLC Software Allen Bradley Poo j 1 View Linx Equipment dome Schneider Hand gchneider 99998C8 1 138 95 5000 5138 95 Off Auto 20 Amp QO dome Square D 0020 1 12 00 5 00 17 00 Dayton 24 Volt dome Coil 10 Amp Dayton 5ZC11 10 5 65 10 00 156 50 Relay dome Disconnect Switch Square D L211N 2 14 00 0 00 28 00 dome Terminal Blocks Phoenix Purchased 30 0 34 0 00 10 20 Contact dome 8 Anip Triad Donated 1 Donate 0 00 Transformer Equipment dome Barcode Sensor Symbol Donated 1 0 00 quipment dome Pushbutton E stop Square 1 11 00 0 00 11 00 dome Motor Soft Start Telemecanique Altistart 01 1 99 00 7 00 106 00 dome PLC ASCI Card Atten Bradley 1771 DA 2 82500 5 00 60 00 RS 232 dome Indicator Light Square D 111 1 19 99 0 00 19 99 8 Amp and 5 Amp CC Dule dome Fuse amp Holders Buss Elmt 2 5 00 5 00 20 00 THHN W
7. D Converter Converter Figure 15 Error Correction The startup function of the PLC is to check the weather conditions If there are any hazardous weather conditions such as rain snow or wind the shutter will not open This is to protect the equipment inside the dome If the weather is good the shutter will open and the dome will be operational During the routine check of the system the weather is always checked If there is any sign of bad weather the shutter will close and remain closed for five minutes The routine check also checks for any error in the domes rotation If any error is detected an output signal will be sent to the motors to for correction This routine check occurs every Sms 38 start Up commands Routine Check commands FIC Scan Routine 5ms Figurel6 Routine Check 5 3 2 2 PLC Code The PLC is controlled by latter logic The name latter logic comes from the format of the code As shown below the code takes the form of a latter containing multiple rungs All rungs contain input functions located on the left followed by output functions on the right Each rung is ether true or false Depending on the input functions if the rung is true the output will be energized If the rung is false the output will be de energized The code is broken up into two sections which include the Dome Rotation and the Shutter Code The Dome Rotation cod
8. be done while an observation is running that means that all sensors need to be tested to make sure they are working test the laser to make sure it is aligned and functioning properly test all motors and look for and fix anything that may be hazardous to the equipment while under operation The weekly and monthly tasks may change as needed but should include all of the before mentioned items so that when the observatory is needed there will be more time to fix any issues Weather Check Part of scheduling the dome is to be able to give feed back to the desired user about the weather and what to expect Knowing what to expect from the weather will give the observatory maintenance the ability to give users a go no go for observations and time to check the weathers sensors to ensure they are functioning properly so that no equipment gets damaged Computer Maintenance The computers software should be updated regularly and so the user should be familiar with the software and should be ready to install any new updates when they are distributed The computers operating system Windows Xp needs to be kept up to date on critical patches released from Microsoft all new critical patches are released on the second Tuesday of every month The virus scan should be checked at least once a week to make sure that its virus definitions are up to date The computer s hard drive should be imaged onto a separate hard drive once every three to six months so that in the ca
9. gt SOL Wale as e ed sel 47 02 2 s Vibration Ciro 48 OMNE iru 48 6 3 1 Software Selection 48 632 49 6 3 3 Vibration 50 6 3 4 Cable Interfacing TRAE SEA NN E SNR AN kite 50 ImplementatlOH voip tos eo dedi v qat 52 6 4 1 Computer Software eee 52 OILS Camera Mstallation cuoco estu UO MEM istos 53 643 Floor Mounting Vibration Control 0 0 00000000000 000000000000 54 644 Telescope Alignment SS AER IN 54 645 so NS eI di 55 PURINE SCOPE or Work Sk 57 1 1 What Has Been 57 To Bessons Lene SS 58 To Power Installation Ne 59 SME RES 60 a e e e a r a ee a e 60 8 2 Dome Instructions ee tete e RV CO S AT EE E ai 61 IVES ET 64 18 0 Special Thanks 0 Sponsors Ec et lions 64 List of Figures EIGURE OVERALL SYSTEM es eve rte 7 FIGURE 2 AN BL as 8 FIGURE 3 SINE WAVE TO SQUARE WAVE CIRCUIT
10. process simpler It was a little difficult 15 to use at first because of the lack of available online documentation as well as the documentation that came with the installation But the program does contain a very well organized help section From that the program was able to be used The first difficulty with the program and PLC was getting the modules to work The analog input module needed to be calibrated The calibration was done by hand looking through manuals and the documentation That did not work Then it was discovered that the program RSLogix5 will put the correct calibration lines of code into the program Knowing this before hand would have saved quite a bit of work Ladder logic is not executed sequentially as is done in C and other programming languages Each rung or instruction on the ladder is executed at the same time The best way to help understand ladder logic is to think of each rung as a logic expression If the first condition s is are true then the instruction will be executed If a rung is empty before an instruction that is considered as a true value and the instruction will always be executed each time the program is swept 4 2 1 Weather Program The weather program is the first step in accomplishing tracking of the weather conditions around the dome and closing the dome in inclement weather conditions This program is set up to take the sensor data and interpret that into the corresponding measurement va
11. s built in data base This is because the telescope has to be aligned each time it is moved If it isn t realigned after someone moves it then it isn t able to locate stars accurately One of the biggest problems that had to be overcome when using a computer to control the telescope and collect photographic data was vibrations The vibrations would cause stars to jump around on the screen when photos were being taken To help stop this vibration control pads were installed under the tripod of the telescope By mounting the telescope on these pads the vibrations were lessoned but not entirely eliminated Since the operation of the telescope is still not completely automated people walking around the dome are a major cause of the vibrations When the project becomes completely usable offsite these vibrations will no longer be an issue 6 4 4 Telescope Alignment The telescope system comes with the ability to slew the telescope to stars that are selected either with the hand box on the telescope or with the Autostar Suite on the computer For either of these methods to work the telescope first has to be aligned so that it knows where it is in reference to the stars that it has programmed into the database The alignment process 56 includes the telescope finding north finding where it is level downloading its approximate GPS location and having the user center at least two finder stars in the center of the telescope viewing area The more sta
12. the space equipment and time needed to complete each part of the project 7 3 Power Installation Issues The biggest critical path for this project was the power installation The dome is located on government property which meant that the universities electrician was needed to install the power throughout the dome After drafting up the power grid facilities were contacted to install the system At one point it was mentioned that it could take up to a year and ten thousand dollars for the electrician to complete the job After some persuasion with facilities an electrician came and installed the power grid The problem was the timing issue and cost associated with the installation Final testing could not take place until all of the power was installed Because of the long time period for the power grid to be installed only individual testing could take place This was a good lesson to learn for future use The lesson learned is that outsourcing anything can take quite some time It is in the best interest of any project to contact the provider well in advance in order to schedule any installation processes 59 8 0 Maintenance 8 1 Duties Because the Rocky Mountain Space Grant Observatory is part of the Space Grant Internet Telescope Network SGITN there will be a need to have someone there to maintain the observatory to ensure that it is functioning properly and will perform any fixes that may need to be done to the dome Some of the
13. to the PLC which would then compare the telescopes position with the domes position Depending on the accuracy level selected the PLC would send out a rotation signal to the induction motor to align to the telescopes position within the tolerance level During the Critical Design Review the customer agreed that this would be a very accurate way to position the dome however a simpler design was wanted The consensus of the customer was that there was an easier way to control by using light sensors and that is what was wanted 5 1 3 Summary of Final Results Upon customers request the design of an array of CdS cells was implemented which includes the induction motor Below is a brief description of the implemented design which will further be discussed in detail in following sections An account of cost issues the motor used for the final design is the induction motor As result of using the induction motors a soft motor starter was purchased and installed to help preserve the life of the motor This allows the current flow to linearly increase to the motor to 29 prevent a sudden current spike The current flow by the soft motor starter can be controlled by the user to allow for optimal control As mentioned above an array of CdS cells is used for feedback of the domes position The array has three positions which are Rotate Counter Clock Wise Maintain Position and Rotate Clock Wise respectively The cells are mounted to the telescop
14. 2V voltage regulator circuit is used see power section The output of both the temperature signal and the relative humidity signal ranges from 0 001V to 1V These output signals are also analog The PLC has an analog 13 input card that can read voltages from to 5 volts with a precision of 12 bits 4096 values This leaves 819 values to read the 0 001 to 1 volt 1000 values This will loose some accuracy of the temperature and relative humidity reading but not a significant amount for the needs of this system The data loss is somewhere on the order of 0 2 degree and 0 2 humidity The PLC will read in these values and compute the temperature and relative humidity and based on predetermined data will close the dome see Weather Research section 4 1 4 Sensor Manuals Below is a table of links to the sensor manuals These can also be found on the project website http rmspacegrant googlepages com Sensor Manual 525 Rain Gauge www campbellsci com documents manuals te525 pdf 03101 R M Wind Sensor www campbellsci com documents manuals 03001 pdf HMP45C Temp Hum www campbellsci com documents manuals hmp45c pdf Table 2 Links to Sensor Manuals 4 1 5 Weather Research Some weather research has been performed to help determine the thresholds of the weather conditions in order for the dome to close The dome will be closed if any of the conditions occur humidity rises above 95 the rain bucket ever
15. Block Transfer Rack 000 Group 2 Module 0 Control Block N9 0 Data File N9 10 Length 64 Continuous No Setup Screen lt Timer On Delay Timer 4 0 Preset Accum Wednesday April 02 2008 00 15 09 LAD 2 INITIALIZE Total 11 B3 1 1001 B3 1 0006 CU 3 17 3 1 004 B3 1 0007 CL 1 2 B3 1 TON 0008 Timer On Delay 2 Timer T4 1 Time Base 10 CDN gt Preset 2 lt Accum 0 lt B3 1 1001 B3 1 0009 CU 2 15 2 0010 gt 1 Page 2 Wednesday April 02 20 15 Figure 17 Rotation Code Table 4 Shutter Code Overview Rung Inputs Outputs if Energized 0 PRECIP True if any precipitation is WEATH BAD Latches a bad detected weather bit W_SPEED True if wind speed is above SHUTTER_TIMER Resets the designated amount shutter timer 1 WEATH BAD True if rung 0 is true CLOSE Outputs a signal to the shutter motor to close the shutter SHUTTER_TIMER Sets a timer to count down from five minutes 2 SHUTTER_TIMER DN True if the WEATH_BAD Unlatches the five minute countdown is complete weather bad bit and check again This allows if the weather ever goes bad to recheck the weather every five minutes 3 WEATHR BAD True if the weather is OPEN Outputs a signal to the not bad shutter motor to open the shutter 4 Indicates the end of the latter 44 DOME CONTROL LAD 3 SHUT
16. Humidity on middle variable tage Conversion middle Variable Humidity sensor Voltage Rain amount hes in one hour Rain Amount i iches in 24 hours Wind Sensor F Wind speed without const wind speed Temperature humidity Rain calculation calibration number Wind calibration ier wina speed Calibration constant Temperature calibration Calaclulation middle value ca AD input labratior 5V AD max voltage Rain Greater then Voltage in two s complement Rain Theshold voltage in two s complement zero Temperature Calibration equation Seconds for wind Temperature Calibration multiplier Humidity calabration multiplier Current day of the month current hour of the day Block Transfer Read control block Block Transfer Write control block Read data block Power up bit Temperature Humidity Wind Rain Write data block Timer for Wind Sensor 10 Wind Timer Done Delay for 24 hour rain update constant Seconds information download Figure 7 PLC Variable Memory List The next step in the dome opening control program is to implement the open and close routines of the dome along with the verification of good weather conditions for dome operation The first part is to include a bit in the PLC that will be set or reset using the computer to signify 24 that the telescope is in use set or not in use reset This means to open the dome for operation or close it because
17. Results NOU REN 29 5 2 POE MASE 30 au T Reyiew GPO EN SR 30 52 2 Design Considerations eiut asap testi de GETS 30 5 2 2 1 Limit e tete 31 3 2 Motor Geb dre Et 31 52 3 Summary of Spears 32 5 3 Detailed Design Schematics and Layout sess enne enne 32 c ui eh cnet io itas tu oe Sot sot eL ti ne in 32 SS rmm PEE 32 SANN 35 SEN db ac c EE 37 5 3 2 1 PLC HardWare didi SN Urea 37 5322 PEC System De NR 38 33 22 PEG Cd tals 39 5 4 Project Implementation Operation and 46 Current permene 46 542 Finishing Work Process APR UNA EN EU Rat 46 24 21 Power iUi 46 DAD 2 X Tose Sh tter Weather scion 46 TL NOR SR 47 JA DOE Ree 47 6 0 Telescope SUDSVSIem eoe tiep aay aeons A AE Ei 45 6 1 45 Telescope 45 6 12 Location Operating Conditions eese tite eae YI end 47 62 Dem Constraints dott OR desee DANS 47 uL
18. Rocky Mountain Space Grant Observatory Final Report Table of Contents T ble of Contents M 1 PISS UT AC 4 Group Members gud ai Boss od 5 1 0 coii 6 20 SPrOBlemic Statement redo iSo ptc p ST 6 340 Project Organization ascenso aso ica NR 6 2 Deam xoc n eed E 6 2 22 Semester TIMENE T Tm 6 A Cost ESUITIAUOD P QUU d c a Eden 8 20 Weller 12 CNET EE 12 TB525 Rain Gauge a 12 4 1 2 OB TOL AR M Wind Sensor sieca no doe taU 12 4 1 3 HMP45C Temperature Humidity Sensor 13 Sensor 14 4 52 Weather RGSS ARC 14 41 6 Sensor Set Up usaram idear 14 FT See 15 22 SANE TG 15 42 1 Weather 16 422 Dome Control res 24 dc TOW eee 25 d b MCSA VAS e aM ette 25 452 Data LOSSIN ass Mis uvae dados att 26 5 0 Dome Operations 26 SE Sunnaas OL Design Proteus 26 DEOR 28 5 1 2 Design TWO 29 51 3 Summary of Final
19. Source 7 6 30 lt Dest F8 6 0 0 lt Multiply Source A F8 6 0 0 8 12 1 677 lt Dest F8 7 0 0 lt 21 0012 0013 0014 0016 ADD Add Source A Source B Dest MUL Multiply Source A Source B Dest DIV Divide Source A Source B Dest MUL Multiply Source A Source B Dest SUB Subtract Source A Source B MUL Multiply Source A Source B Dest F8 0 2560 0 N7 0 4095 lt F8 1 0 6251526 8 1 0 6251526 lt 7 180 F8 14 112 5275 F8 14 112 5275 22 0018 0019 0020 Figure 6 Weather Program Ladder Logic DIV Divide Source A Source B Dest MUL Multiply Source A Source B Dest 8 3 0 2100122 N7 8 100 F8 10 21 00122 23 Address 1 53 7 4 6 ret 8 5 10 5 10 3 10 0 14 16 T4 0 DN T4 2 T4 2 DN T4 2 TT T4 2 EN 4 2 2 Dome Hatch Control T MID T VOL H MID H VOL R IN HOUR T AD C AD 5V W THES R THES ZERO T CONST W SEC T MUL H MUL STD DAY STD HOUR N H W R W TIME R DAY DEL CALABRATION AY Global Global Global Global Global Global Global Desc ription Run Program Block Transfer Write configure bit Wind Counter Wind sensor frequency in 30 seconds Rain Counter Rain Count Amount in one hour Rain counter is gt 1 count Hour Counter Done Temperature Conversi erature sensor
20. TER Controls the opening and closing of the shutter Total Rungs in File 5 B3 0 CL 1 GRT 149 Greater Than A gt B RES Source A F8 8 0 4 lt Source B N7 11 15 lt TON Timer On Delay Timer Time Base Preset Accum Monday March 31 2008 12 01 00 Figure 18 Shutter Code 5 4 Project Implementation Operation and Assessment 5 4 1 Current Implementation Currently there are several things being implemented that affect the scope of our project There is currently an electrician from USU facilities that is terminating all transmission lines into the dome panel that are landed onto control contacts From the panel the electrician has bent conduit that leads to the different components of the observatory pulled wire through the conduit and is in the process of wiring up power grid system Along with the power installation process individual module testing is taking place with the domes rotating program weather program and shutter program 5 4 2 Finishing Work Process After the wiring is completed the system testing will begin The system will be tested with all integrated subsystems Testing consists of several parts listed below 5 4 2 1 Power Failure The goal for testing the Power Failure is to maker sure if there is any power loss the Uninterruptible Power Supply UPS will shut the shutter This test will be performed by manually cutting off all power to the dome The test will
21. These operating zones have been picked because in the case that the telescope starts slewing in any given direction the dome will have time to ramp up the motor and catch up to the rotation of the telescope without obstructing the view of the telescope The laser will be mounted to the side of the dome 90 degrees from the shutter opening to reduce the amount of light that may shine on the cells accidently activating one and producing false information The laser will also be mounted one foot high up the side of the dome to avoid obstruction from the motor Figure 12 shows the setup that will be used for the CdS cells and laser as well as the viewing angles Figure 13 shows the circuit diagram for a region of the CdS cells Each region returns a single TTL signal back to the PLC The TTL levels are produced by the use of op amps the CdS cells generate an analog signal which depends upon the amount of light on the cell the op amp then takes that voltage and outputs 5V if the cell has been activated or OV otherwise There is one 35 op amp for each CdS cell and the output of the op amps are then taken and checked through series of OR Gates to see if any cells have been activated if any cell has been activated then the circuit outputs a TTL level signal to the PLC Figure 12 Hardware Setup vec INSTALL 3 EACH OUTPUT TO PLC PHOTOCELL DETECTOR CIRCUIT Document BEN JEPPSEN
22. View32 has a built in data logging functionality that is very user friendly After some initial set up this feature is very quick and easy to use and changes to meet the users needs The following is a list of steps that were taken in order to begin logging the weather data after tags were created 1 Decide which format to use 2 Decide where to store the data 3 Decide when to create and delete log data 26 4 Decide what actions will trigger logging data 5 Decide which tags to log data for 6 Decide what to call the model The data is stored in dBASE IV dbf wide format which is a table type format This format stores one date one time and all the tag values per line This is a more useful method then the narrow format option for storing periodically changing data The data files are also stored using long file names The format is YY YY MM DD NNNN Weather System wide dbf where YYYY is the year MM is the month DD is the day and NNNN is the sequential file identifier This number indicates the sequence files were created in You can have up to 9999 file sets per day At midnight the sequence starts at 0000 again The data files will be stored on the hard drive of the desktop computer in the Rocky Mountain Space Grant Observatory The path they are saved under is C documents settings aggie obs desktop RS View help RS View program weather station DLGLOG weather report model The system is currently set up to keep data log files for 12
23. able was required to be a minimum of 7 62 meters to reach from the telescope camera to the computer To overcome the length issues so that the camera would be able to communicate properly an active USB extension cable had to be used instead of the normal passive USB cables This allows for two 5 meter cables to be hooked together without the same problems The reason the active USB cables didn t run into the same issue is that they double the signal voltage and act as buffers for the signal in both directions so that the round trip delay time is met The impedance of the USB cable and the USB ports were matched at 900 so no further impedance matching was required The connection between the telescope and the computer used a combination of RS232 and RJ11 phone cords A RS232 port had to be selected to be installed on the computer since there wasn t one available The port that was selected fit into an I O expansion slot on the 53 motherboard of the computer and was Windows XP compatible 3 wire RS232 connection is used by the telescope Since this is the case and not all nine connections on the RS232 would be used a DB9 to RJ11 adapter was selected to be used to plug into the RS232 port on the computer Then the RJ11 phone cable was selected to be used to connect between the adapter and the telescope The RJ11 phone cord was selected to be 7 62 meters long It had to be this long to reach between the computer and the telescope since they are n
24. acing between the different components of the system was an important part of the design process If any of the interfaces didn t transmit data properly without data loss or corruption then the system wouldn t be able to communicate from one device to another properly The main ways that the interfaces could corrupt data would be due to the voltages on the lines dropping below readable levels due to the lines being too long or due to reflections or rejections that arise from improper impedance matching Great care was taken to ensure that this didn t happen on any of the interfaces or cables used in the design A flow diagram showing the connections and cables is shown in Figure 22 52 USB 2 0 2 Active USB Cables USB 2 0 PORT 32 Ft 90 Ohms PORT RJ11 Port 600 Ohms RS 232 Port RS232 to R11 2k Ohms Adapter TEL 25 Ft 600 Ohms 90 Ohms 90 Ohms 480 480 Mbps Jade daag YILNdINOD Figure 22 Interface Flow Diagram The design used a USB cable to connect from the camera to the computer The use of a USB cable was a potential problem because a normal USB cable is only able to reach for 5 meters before it can no longer properly transmit data This is because the maximum round trip delay for a USB cable is 26 ns and the delay in a USB cable is 5 2 ns per meter The voltage that USB cables use to transmit data falls below the 2 8 to 3 6 voltage range for cables longer than this The c
25. ank our many sponsors for making this project possible We would like to thank ATK and Allan Bradley for the donation of the PLC and operating software We would also like to thank Rocky Mountain Space Grant and USU for the financial and design support throughout the project Without these sponsors this project would not be possible 65
26. art functionality as shown in the schematic the PLC will stop and start the soft starter motor Figure 9 Soft Starter 33 Initial voltage Adyustabie Voltage start ramp Initial voltage and up te speed Figure 10 Voltage vs Time Graph 24 Vdc or 120 Vac Supply 3 Figure 11 Soft Start Wire Diagram Coast Io Stop 110 240 V ym ATSOIN1 FT 34 5 3 1 2 Sensors The sensing system that has been tested and implemented incorporates the use of CdS Cells Cadmium Sulfide Each CdS cell represents two degrees when mounted to the base of the telescope There is a total viewable window of 48 degrees in which the telescope and view the stars without obstruction from the sides of the dome The CdS cell array will be mounted to the base of the telescope and a laser will be mounted to the side of the dome which shines on the cells activating a single cell which then relays that information to the PLC notifying it of the status of the domes position The cells will be organized into three groups of eight cells each The center eight cells will be the maintain zone when in that zone the dome will stay put the right eight cells will be the correct clockwise when in that zone the dome will rotate clockwise until it is in the maintain zone again the left eight cells will be the correct counter clockwise when in that zone the dome will rotate counter clockwise until the maintain zone is reached
27. close to 360 in the opposite direction and continue to follow the telescope The downside to this solution is that there will be a few seconds of obstruction for the telescope 5 2 2 2 Motor Delays While manually rotating the dome the following observations were made When the induction motor is on and shuts off the dome has built up rotational momentum It takes anywhere from one to two seconds depending on how long the motor has been on for the dome to slide to a complete stop When the motor is directing the domes rotation in a clock wise rotation and very quickly switched to rotate the dome in a counter clock wise rotation the motor continues to rotate in the clock wise rotation The same is said in the opposite direction The solution came through testing time delays There needs to be a two second delay before the polarity of the motor can switch and work properly This time delay takes place in the PLC code This fix is very important for the limit switches because they require a direct switch in rotation When a very quick switch is necessary the time delay will cause the dome to lose any previous momentum and rotate in the proper direction 31 5 2 3 Summary of Specifications The list below contains specific design specifications for the subsystem of the dome rotation Include in the specifications are power requirements The power specification do apply to the domes rotation however does not affect the design of the rotation sy
28. e controls the complete rotation of the dome and the Shutter Code controls the domes shutter to close if the weather is bad Latter Logic does not allow for any comments to be displayed therefore also included below is a table indicating the functions of each rung Table 3 Rotation Code Overview Inputs Outputs if Energized 0 These rungs were produced by RSLogic for the initialization of the Input and 1 Output cards that used by the PLC 2 CCW_IN True if the counter clock wise CCW OUT Sends an output to CdS array is hit by the laser the induction motor to rotate the 39 LATCH_CW True if the limit switch for the clock wise rotation is not initialized LLSD_DN True if the timer has counted up to the designated time dome in a Counter Clock Wise rotation If the LATCH_CW is latched it causes that part of the rung to be false turning off the motor CW_IN True if the clock wise CdS array is hit by the laser LATCH_CCW True if the limit switch for the counter clock wise rotation is not initialized RLSD_DN True if the timer has counted up to the designated time CW_OUT Sends an output to the induction motor to rotate the dome in a Clock Wise rotation If the LATCH_CCW is latched it causes that part of the rung to be false turning off the motor LIMIT_R True if the right limit switch has been triggered LATCH_CW Latches a bit i
29. e 21 Envisage Imaging 6 3 2 Camera Selection The camera that was selected to be used is the Deep Sky Imager Pro II made by Meade It was selected from several possibilities The main choices were narrowed down to the Deep Sky 51 Imager II the Deep Sky Imager Pro II the Orion Star Shoot Deep Space Imaging Camera II These three cameras had similar resolution and exposure times They also all operated by using a USB cable This was important since they used the 5 volts supplied by the USB cable for their power needs This meant that none of them operated on battery power which was one of the telescope subsystem design constraints The main reason that the Deep Sky Imager Pro II was chosen was that it came with the AutoStar Suite software which is designed to control the camera as well as the telescope The Orion camera didn t come with software like this The other Deep Sky camera would have also been a good choice but the pro version has several added features 6 3 3 Vibration Control A major factor in telescope photography is vibration control Even small vibrations can cause a photograph to be blurry This is due to the fact that the images being photographed are light years away and extremely magnified It was determined that placing vibration control pads under the tripod of the telescope reduces the vibration levels down to a usable level that doesn t severely affect the picture quality 6 3 4 Cable Interfacing The interf
30. e and rotate when the telescope rotates A laser mounted to the rotating dome is used to trigger the CdS cells Depending where the dome is the laser will be pointed in one section of the CdS cells The output will be sent to the PLC indicating the error or the difference between the telescopes position and the domes position Through PLC control the proper output will be sent to the motors allowing for any correctional rotation 5 2 Problem Analysis 5 2 1 Review of Problem A computer controlled observatory system will be capable of remote operation through the interfacing design of a programmable logic controller PLC The observatory dome must follow the rotation of the telescope as to provide means of visibility and protection of the equipment contained within 5 2 2 Design Considerations Upon inspection of the observatory certain design considerations were implemented into the overall design of the project 30 5 2 2 1 Limit Switches The dome has a shutter motor mounted on the rotating dome A long wire providing power to the shutter motor could easily be wrapped around the telescope if the dome rotates more than 360 The solution to this problem is to add limit switch to the dome This will prevent the dome from rotating more than 360 a single direction The cord will wrap itself around the telescope but not enough to cause any harm or obstruction to the telescope If a limit switch 15 hit the dome will rotate
31. e dome follow any rotation thereof allowing for an unobstructed view into the night sky The dome must also be able to close when any bad weather is detected in order to protect the equipment inside Engineering steps that have been completed include the designing of a complete operational system installation of individual components and necessary control programs written Along with all installation individual testing of components such as the laser CdS sensor array weather program shutter program and rotation program have been completed Currently the power grid is being installed This includes all of the conduit and wiring of high voltage components such as power from circuit breakers to the PLC relays motors switches and transformers to the power supply The completion of this project is a little behind schedule do to the critical path of the power installation After the power installation is complete the final testing will begin The final testing is the last part of the project and after completed the project will be function according to specifications from the users The total cost of the project including all subsystems has been accepted and approved by the customer Both the design and report are engineered to meet customer specifications Any necessary steps will be taken to ensure that the customer is completely satisfied with the implementation of the project 10 0 Special Thanks To Sponsors 64 We would like to th
32. elescope subsystem is part of the Rocky Mountain Space Grant Observatory project It will be used by the interested public to view astronomical objects such as stars and planets This project will allow the telescope to be accessed by a remote computer which will give interested youth access to a science experience that they otherwise would not be entitled to Hopefully using the telescope will help interest them in pursuing a science based education 47 The telescope that is being used for the Rocky Mountain Space Grant Observatory is the Meade LX200R 14 When the project began it was located in the basement of the engineering lab building It was not set up and there was no user s manual Later a user s manual was acquired and the telescope was properly set up in the dome The initial setup included taking the telescope parts out of the box setting up the tripod connecting the telescope body to the tripod plugging in the correct cables and aligning the telescope by centering specific stars Proper implementations of a camera and software package that connect to the telescope now allow the telescope to be controlled remotely by a computer This includes both moving and focusing the telescope The telescope subsystem consists of the telescope itself a CCD camera vibration control hand box control a computer telescope control computer software camera control computer software and connecting cables The main block diagram for the sys
33. equires that the telescope be able to be completely controlled by a computer at a different location This control must include being able to slew the telescope from one star to another being able to focus the telescope and being 49 able to control a camera hooked up to the telescope Since most of the users of the telescope won t be astronomy specialists it is vital that the computer programming provides a way to make the telescope find selected stars on its own This would make the telescope more appealing to use which is one of the main considerations for the project since it is being used by the public to promote science learning 6 2 2 Vibration Control Photographs from the CCD camera on the telescope are sensitive to vibrations from the surrounding environment Therefore some mechanism to reduce the vibrations felt by the telescope and subsequently by the camera needs to be implemented The vibrations need to be reduced to the point that they don t adversely affect image quality 6 3 Designs 6 3 1 Software Selection Since the telescope is to be operated remotely a software package that was able to control the telescope and camera had to be selected The software that was selected is the AutoStar Suite It is able to completely control the telescope and camera It has a star map incorporated into the software A star can be selected on the map and the software will move the telescope to that star s location The program also allow
34. er motors can be controlled precisely to a specific direction without any feedback information They are made for quick stop and go movements in either direction while also providing the ability to move for a long directional time span A stepper motor would provide the system with an exact angel of the domes position allowing the PLC to compare the domes location with the telescopes position The comparison would take place in the PLC allowing for any correctional position to be output to the stepper motor The downside to using a stepper motor and ultimately the reason for not choosing this design was the cost issue In order to control a stepper motor a driver is also needed The total cost for both the driver and the stepper motor selected is 440 28 5 1 2 Design Two The second design consisted of using the already installed induction motor integrated with a bar code scanner The purpose of the bar code scanner is to provide feedback information to the PLC containing the domes position Bar codes would be placed every five degrees around the dome while the scanner would be mounted stationary by the induction motor As the dome rotates the scanner would scan the bar codes which contain the position in degrees of the dome The scanner was set to scan at 10Hz allowing for a fast enough scan to ensure the bar codes on the dome would be read no matter how fast the dome rotated As the scanner read a barcode the position of the dome would be sent
35. ful process of checking each component of the circuit In order to check each component maintenance will be provided with the circuit diagram and with a voltmeter to check the components When the failed component has been found it will need to be replaced with the same functioning part PLC Failure If the PLC is not functioning properly the code may need to be reloaded If the code has been reloaded and the PLC is still not performing correctly it may need to be restarted If the previous two items did not fix the issue then maintenance will need to refer to the PLC user s manual which will be provided Computer Failure If the computer fails to start then maintenance needs to either have a technician locate and fix the issue or maintenance needs to fix it their self If any data is lost or if the hard drive has been replaced then the image of the hard which should have been made every 62 three to six months will be placed back the hard drive If the hard drive was never imaged then maintenance will have to reinstall all software and get the telescope running again Updating the Website The project website can be viewed at http rmspacegrant googlepages com If additions or edits need to be made they need to be performed by going to http pages google com The login name is rmspacegrant and the password is aggieobs Included are some helpful tips for updating the website To create a new link first select the page you wo
36. g and end of the observing session and it s actually possible to do other things like your homework while taking long exposure images The Rocky Mountain Space Grant Observatory located at Utah State University is one of six telescopes in the SGITN The others are located in North Dakota and South Dakota Current Group Members Systems Lead Scott Farnsworth Weather Matt Pine Brok Thayn Monica Berrett Dome Operations Ben Jeppsen Evan Howard Nate Erni Telescope Brok Thayn Matt Pine Former Group Members Systems Lead Josh Williams Dome Weather Brok Thayn Scott Farnsworth Matt Pine Monica Berrett Controls Ben Jeppsen David McDougall Khemmer Porter Dan Morgan Telescope Quinn Vellinga Xing Wei McKay Williams Mac Fillingim 1 0 Introduction Utah State University USU is currently working on a web based telescope in conjunction with other universities and organizations around the world Each university or organization will have their own telescope making a network of telescopes around the world These telescopes will display the images they observe on the web in real time Students will be able to login to the website and reserve the telescope for a predetermined time The student using the telescope will have the ability to direct the telescope wherever they see fit Having a network of telescopes allows the user to look into space during the daytime by accessing a telescope in another part of the world f
37. goup Implementation 2120 08 4 2 08 Ess Implementation 3 20 08 5 1 08 2 1 08 2 2 08 CDR 2129108 3 1 08 hove emanate e le ve fe bo pe bo le fo gt gt gt fv amp PO Ob 1 11 09 E gt Preliminary Implemetnations Weather Equipment Access Hole 1 18 08 1 19708 1715108 119108 11108 129108 1 11 08 123 08 Mns 2308 11100 25109 Dome Operations Figure 2 Gantt Charts The initial layout of the project included only preliminary preparations and as the group began to ascertain specific needs for the project additional tasks were added and specific group organization began to take place 3 3 Cost Estimation Below is a table which consists of a parts list and the associated cost for the rotation of the dome This table only includes parts needed and does not include any engineering time spent on the project Subgroup Item Brand Model Qty Price Shipping Total telescope USB extender Vigor VAD 1120 1 39 99 4 98 44 97 telescope Telescope Meade LX200R 14 1 0 00 Equipment telescope Ultra Wedge Meade LX200R 14 1 499 95 15 00 514 95 telescope CCD camera Meade Imager PRO 1 0 00 I Equipment weather Campbell HMP45C 1 214 00 0 00 214 00 weather
38. iable you wish to have access to Creating a tag requires the address of the variable see Figure 8 a type possible maximum and minimum values units and a scan class The possible types are analog digital 25 string and system The scan class is used to set how often the variables tag will be updated from RSLogix5 For the weather system six tags were created one for each of the following variables run rain in hour rain in day temp hum and wind of the tags except run were set as analog floating point numbers so they can accept a range of values Run is a digital tag that takes on the values 0 no go or 1 go and can be used as a system override All of the tags were set up in the same scan class with a scan time of five seconds This means every five seconds RSView32 will check the address location for all tags in RSLogix5 and if the values have changed they will be updated in RSView32 A window called Tag Monitor is used to view the current values of each tag It is set up and saved as an Excel spread sheet and contains all six tag names a description their current value and their current state The state refers to if the tag is valid It could also be undefined or and error if RSView32 cannot find the desired address in RSLogix5 This was used often in the testing phase to make sure the readings RSView32 was acquiring were the correct ones and that they updated when the sensor inputs changed 4 3 2 Data Logging RS
39. ire as THHN 14 dome fee Gn te Any AWG 100 0 30 5 00 530 00 dome Limit Switches Allen Bradley 02 2 10 00 5 00 30 00 5115 dome UPS Power Waire 1000VA 1 300 00 20 00 320 00 dome Drive Wheel True Wheel True Wheels 1 50 00 5 00 55 00 dome PS 2 to RS232 Awce Awce GP 2 1 50 00 5 00 55 00 still need to purchase Total Cost 3 850 06 11 Table 1 List of Materials 4 0 Weather Subsystem 41 Sensors 4 1 1 525 Rain Gauge In order to protect the telescope from precipitation a rain sensor is incorporated into the system USU already has the 525 rain gauge sensor so that is being used 525 works as a simple switch When rain fills up the tipper it tips and closes a switch Each tip represents 0 01 inches of rain have fallen The input to the TE525 will be 5VDC The output signal will be a 5V pulse wave which will be directly inputted into the PLC s TTL logic board where it will count the pulses frequency The PLC will count the pulses over a predetermined amount of time to determine if it is safe for the dome to open see Weather Research section During the winter a snowfall adaptor will be placed on top of the TE525 which will melt the snow to have the TE525 work if it were raining 4 1 2 03101 Wind Sensor In order to protect the telescope from debris in the air an anemometer is incorporated into the system The anemometer that is being used is the 03101 R M Wind Sensor
40. it is not needed at the moment This variable will be called IN_OPER for in operation The next thing is to implement a routine that will always check the weather data to verify good operating conditions while the IN_OPER bit is set If the conditions are good the dome can stay open and be used otherwise a close dome routine is triggered and executed After an inclement weather condition triggers a close dome routine the program will need to wait a certain amount of time or wait until conditions become optimal again before allowing operation to resume The only weather condition that has been quantified as a close the dome specification is if one pulse from the rain sensor is measured The other conditions temperature humidity and wind have not been significantly quantified for good weather operation The other values need to be specifically quantified The code for the Open Close function of the dome is described again in the dome operations section 5 3 2 2 The ladder logic code is given along with more explanation 4 3GUI RS View32 The RSView32 software has the capability of retrieving and monitoring variables located in the RSLogix5 code RSView32 is able to do this using a software program called RSLinx Classic Although the capability is there to also store information from RS View32 onto the PLC this project won t be utilizing that feature 4 3 1 Creating Tags The first step in monitoring the code is to create a tag for each var
41. ix5 That is followed by a list of the variables used in the PLC memory IO and their address location symbol and description 18 0000 0001 0002 BIW Block Transfer Write Module Type Generic Block Transfer Rack 000 Group Module Control Block N9 5 Data File N9 22 Length 11 Continuous No Setup Screen BTR Block Transfer Read Module Type Generic Block Transfer Rack 000 Group Module Control Block N9 0 Data File N9 10 Length 8 Continuous No Setup Screen 19 MOV Not Equal Move Source A 21 Source 11 lt Source N7 10 11 lt Dest ADD Add Source A Source B Dest MUL Multiply Source A F8 4 Source B Dest MOV Not Equal Move Source A 5 20 Source S2 0004 Source B N7 9 Dest N7 TON Timer On Delay EN Timer T4 2 Time Base 1 0 DN Preset 60 0 lt Accum MUL Multiply Source A F8 5 0 0 Source B N7 4 0 Dest F8 5 0 0 0007 0009 0010 0011 RT Greater Than Source A N9 17 5 lt Source N7 3 250 lt 5 1 DN RT Greater Than A gt B Source A N9 16 14 Source N72 1638 CTU Count Up CU Counter C51 Preset 1 DN 5 Accum 0 MUL Multiply Source C5 1 ACC 0 Source F8 11 0 01 lt Dest F8 4 0 0 CTU Count Up CU Counter C5 0 Preset 1 lt DN Accum 0 lt Timer Time Base 1 0 Preset 10 Accum lt DIV Divide Source 5 0 0
42. lescope Polar Alignment Camera Understand Functionali Test Computer Link Connect Telescope to Computer Autostar Protocol Testing Documentation Telescope January 2008 February 2008 m Begindate Enddate 24 5 ps 30 2 p e ho 16 Hs hz ho 20 21 22 23 24 26 26 27 26 29 1 2 amp Preliminary Implemetnations 1 11 08 2 2 08 Weather Equipment Access Hole 1 15 08 11908 Access between rooms 1 15 08 1 19 08 7 iios C C T New Breaker 1 11 08 23 08 lt Panel location on the wall 1 11 08 1 23 08 Relay Logic Design Finalized 1 11 08 12508 Terminal Blocks 1 25 08 1 29 08 E stop 1 25 08 129 08 7 Switch 112508 1 29 08 Receptacle in panel 1 11 08 1 18 08 First Installation 1 29 08 212108 SSS Conceptual Design of Auto Control Servo 1 30 08 2 22 08 C Alternative Conceptual Design Induction 1 30 08 2 27 08 p F F J J ZZZ20000J J Finalize Induction Motor Interfacing 43008 _ 227 Specification Design Cost Estimate 1 30 08 2 27 08 El Laser Compass Tracking 1 30 08 2 26 08 er ProsiCons 228 Testing 1 18 08 3 19 08 Troubleshooting 2120108 325 08 Hj Sub
43. lle Utah Lake Powell Utah Elevation 500 fe Meters C Feet gt Manti Communication Setup Comm Port Parity Check Carrier Detect Baud Rate C 300 C 600 1200 C 240C 4800 9600 C 144K C 19 2K 56K C 115K Flow Control C Xon Xoff MU C Hardware Data Bits Mone Figure 24 Com Port Settings 6 4 2 Camera Installation The camera sits where an eyepiece would normally go on the telescope The main issue to overcome in installing the camera is to make sure that the telescope mirrors are set up in such a way that they project the image for the right focal length When the camera sits in the eyepiece slot the focal length is different than that of most eyepieces We found that a 25mm eyepiece 55 has the same focal length as the camera and can be used to focus the telescope correctly for the camera 6 4 3 Floor Mounting Vibration Control The telescope is currently mounted on a tripod that sits on the floor This holds the telescope steady and there is not a risk to the telescope tipping over while in use The biggest problem with the mounting is that it is not permanently in place The tripod could be moved around by someone up in the dome Moving its location would interfere with the telescopes ability to accurately locate stars using it
44. lue Then the GUI RSView32 program can take those values off of the PLC and log them into metadata on the computer The next step in the programming process will be incorporating the dome open and close routines which will be discussed later on 16 There are four weather sensors that are being used temperature humidity rain and wind The specifics on each sensor are found in the sensor section of this report These four weather sensors are connected to the PLC using the differential analog input module These four inputs have been set up to give a zero to five volt signal the analog module has been set up to accept this voltage range The analog input module is a 12 bit A D converter as has been mentioned above Therefore the weather signals are broken down into numbers ranging from 0 4095 Zero represents zero input voltage and 4095 represents five volts That gives a resolution of 819 per volt The temperature and humidity sensor gives a voltage value depending on the measurement The rain sensor gives a pulse per 0 01 inches of rain fall The wind sensor and circuitry will also give a pulse signal one per revolution The weather program must take the temperature and humidity data from the analog module and convert that to the actual voltage given by the sensors Then it can use the conversion equations supplied with the sensors to give the corresponding weather condition reading But as for the wind and rain sensor the program must compa
45. maintenance duties will consist of Observatory Scheduling Telescope Alignment Dome Alignment Regular Maintenance Weather Checking and Computer Maintenance Observatory Scheduling There are multiple observatories that are part of the SGITN and because of that there is a need to have someone schedule the dome for observations in this way we can eliminate multiple users from running the dome at the same time Telescope Alignment The telescope is not always 100 accurate in its movements which will cause the telescope to become un aligned over a period of time To correct the inevitable the maintenance person will be trained in the operation of the telescope and will perform regular alignment maintenance The Telescopes batteries should be replaced on a regular basis so that in the event of a power loss the telescope will be able to remember its current position and will not have to be realigned Dome Alignment If the dome is unable to keep up with the telescope while tracking an object the PLC will give an error back to the user notifying them that the dome is no longer aligned Observatory maintenance will go to the observatory and perform any manual realignment necessary Regular Maintenance Observatory maintenance will have a routine check to perform before each scheduled observation as well as monthly and weekly maintenance checks Checking the 60 overall functionality of the dome to ensure that no or little maintenance will need to
46. months 1 year but that can be monitored to see how much space the files require Adjustments will be made as necessary if adequate space is not available by either deleting files sooner or saving them to a different location There are several options available for how frequently to create a new entry in a data file and also when to begin a new file New files can be created periodically every hour day week or month Other options are at a specific date and time or event triggered It was decided to create one new file every day The other decision is how often to log a new entry in the current file This can be done at just about any time interval the user would like The weather system is 27 set up to log a new entry for each of the six tag variables every ten minutes So there will be 6 entries each hour and 144 entries in a file with one file per day 5 0 Dome Operations Subsystem 5 1 Summary of Design Process The design process consisted of several designs which were eventually eliminated until the final design was agreed upon by both the customer and engineers Below is a brief description of designs that were engineered but not implemented 5 1 1 Design One The first design engineered consisted of a stepper motor which would have replaced the current induction motor Stepper motors are commonly used for control systems The two big reasons for designing with a stepper motor are because of its accuracy and life span Stepp
47. ndicating that the latch has been hit This is used in rungs 2 and 5 LATCH_CW True if rung 4 is true TON Sets a timer to allow for the induction motor to stop any momentum from the previous rotation When the count is done it sets RLSD_DN high see rung 3 LATCH_CW True if rung 4 is true CCW IN True if the counter clock wise Cds array is hit by the laser LIMIT L True if the left limit switch has been triggered LATCH CW This unlatches the clock wise latch indicating that the dome is done rotating from the limit switch LATCH CCW Latches a bit indicating that the latch has been 40 hit This is used in rungs 3 and 8 8 LATCH_CW True if rung 7 is true TON Sets a timer to allow for the induction motor to stop any momentum from the previous rotation When the count is done it sets LLSD_DN high see rung 2 9 LATCH_CCW True if rung 7 is true LATCH_CCW This unlatches the counter clock wise latch CW_IN True if the clock wise Cds indicating that the dome is done array is hit by the laser rotating from the limit switch 10 Indicates the end of the latter 41 DOMEFUN LAD 2 INITIALIZE Total Rungs in File 11 BTW Block Transfer Write Module Type Generic Block Transfer Rack 000 Group 2 Module 0 Control Block N9 5 Data File N9 74 Length 64 Continuous No Setup Screen lt BTR Block Transfer Read Module Type Generic
48. or example a telescope in Europe or Asia One of the concerns with the USU telescope is how to protect it from the environment if the system is completely operated remotely The dome needs to be automated and programmed to close when bad weather arises 2 0 Problem Statement An overview of the project is shown in the figure below The flow of this report will be broken down by subsystem The weather subsystem includes sensors and their communication with the PLC Programmable Logic Controller along with tracking and logging data Dome control subsystem consists of the motors sensors and programs coded in latter logic for the PLC The telescope subsystem covers the telescope operations operating and interfacing the camera the equatorial wedge and alignment issues Telescope Subsystem Internet 1 ACP Program Weather Subsystem P si oe ek eens ra i a RC PIU stave Sensor Shutter Motor Rain Snow SUE Rotation Motor Humidity Temp Barcode Sensor Figure 1 Overall System The current Rocky Mountain Space Grant Observatory is completely manually operated One has to get onto the roof of the Engineering Laboratory EL building and manually flip the switch to open the observatory This can be very tedious and time consuming The user has to stay up in the observatory the whole time he or she wants to use the telescope in case bad weather occur
49. ot in the same room The RJ11 phone cord is able to transmit data without out the voltage dropping below critical levels for this length of cord The voltage levels on RS232 are 3 to 15 volts for logic 0 signals and 3 to 15 volts for logic 1 signals The impedance of the RJ11 phone cord and the ports it connects to are matched at 600Q so no further impedance matching was necessary 6 4 Implementation 6 4 1 Computer Software Configuration The Autostar Suite required some setup for it to work properly The correct latitude and longitude of the EL building had to be input so that the software would be able to properly locate stars The Latitude is 41 46 47 N and the Longitude is 111 50 59 W Figure 23 shows a screen shot of latitude and longitude being setup The settings for the com port also had to be set up so that the computer and the telescope could communicate properly The settings were 9600 baud rate 8 data bits no parity bit 1 stop bit and no flow control Figure 24 shows a screen shot of the com port settings being set up An RS232 port had to be installed on the computer since one wasn t available This port is used to connect the telescope to the computer Section 5 c iv explains the cable setup in depth 54 Set Location Coordinates Current Location User Specified Latitude poc Min a ES ma North of the East South Equator West Observatories Cities Hanksvi
50. pass if the shutter closes 5 4 2 2 Close Shutter Weather The goal for testing the Close Shutter Weather is to make sure upon any detection of bad weather the shutter door closes This will be tested by manually tipping the rain bucket and spinning the wind speed sensor above the allotted amount The test passes if the shutter closes 46 5 4 2 3 Sensors The goal for testing the sensors is to make sure the laser will have clean contact with the sensors around the entire dome This test is to make sure that the dome telescope and laser are completely level If there is a slight degree offset on any one of the above listed it could cause the laser to miss the CdS cell sensor array If the array is missed this would cause the dome rotation to fail If in any case the array does not sense the laser within a given time period of 60 seconds an error light will illuminate asking for maintenance This test will pass if the dome rotates a complete 360 while maintaining laser contact with the CdS cell array 5 4 2 4 Dome Rotation The goal for testing the Dome Rotation is to make sure the dome can rotate in a counter clock wise and clock wise rotation upon request from the sensor array The test will pass if the laser is manually pointed on individual sensor sections and the rotation occurs promptly and in the correct rotation 6 0 Telescope Subsystem 6 1 Existing Hardware Conditions Telescope Subsystem 6 1 1 Telescope Subsystem The t
51. re if the input is over a certain amount to signify that a pulse was sent from the sensor The program must accumulate the total number of pulses sent in a certain amount of time Then convert that into the wind speed and precipitation amount The program is laid out in this fashion First are the calibration rungs to set up the analog input module That is followed by procedures to get the current day and hour from the PLC for precipitation time tracking as well as procedures to update that information every hour and day Next is the rain counter and precipitation amount calculation The precipitation is set up to record the amount received in the hour as well as in the whole day The wind timer counter and calculations come after the rain section The wind sensor calibration equation is set up to 17 calculate the wind speed by how many revolutions per second it spins Therefore the wind timer will give the time aspect and the wind counter will count how many revolutions in that time Then the calculations will give an average revolution per timer time ten seconds and that will be used in the calibration equation to give the wind speed Last and not least are temperature followed by humidity measurement calculations These are done by converting the A D value to the voltage value sent by the sensor Then the program puts that value into the calibration equation to give the measurement value Below is the weather program as it is laid out in RSLog
52. rs that are centered the better the alignment will be and the less future users have to adjust the location of the telescope to be centered exactly on the object they are trying to locate 6 4 5 Equatorial Mount The current method of moving the camera to track a star during a photographic session requires the use of two motors One moves the telescope in azimuth and one in altitude This makes perfect tracking hard which can lead to streaking on the final photograph A way to correct this problem would be to install an equatorial mount One type of equatorial mount is a Meade Superwedge The Superwedge would allow the axis of the telescope to line up with the axis of the earth Then only one motor would be required to track a star and the streaking effect would be eliminated 7 0 Final Scope of Work Statement 7 1 What Has Been Done Throughout the course of the semester we have designed implemented and tested multiple parts of the project The latter logic code that will run the dome has been designed tested and reconfigured throughout the semester and is ready to be tested on the entire system The CdS cell sensors was thought of earlier in the semester but was scratched to pursue what was thought to be a better way Half way through the semester we realized that our first idea would be the better way to go and so we finished designing what we had started earlier in the semester The completed circuit is shown in Figures 25 and 26 57
53. s through the progression of the semester An innovative and helpful program was used to organize the layout of the project available for free called Gantt Project February 2008 project m Week 4 Week 5 Week Week Week 8 Week 9 Week 10 Wesk 11 Week 12 13 Week 14 Week 15 Week 16 Wesk 17 start Project Critical Design Review Finish Project Posier Presentation Sensors Wind Sensor Initial Circuit Build Test Additional Circuitry 4 Design Build ni Test l Attach Wind Circuitry to Board Puton Board 1 Test 4 Attach Sensors to Station _ Work Weather Station Operating at Location a Final Test Snow Sensor Snow Sensor Design Snow Sensor PDR Implementation Documentation GUI Interface finish Up rest of GUI Programming Final Test Documentation Ladder Program Weather Tracking d Alter Program Test Programming Test Final Tweaking Programming Final Test Documentation Weather Constrainis Calibration 4 Weather March 2008 Telescope Sub group Start Project Change group Assignments Critical Design Review Project End Setup Telescope Level Tripodiset up telescope Align Telescope etc Understand functioning Equatorial Wedge Footprint Get Made order Attach io Te
54. s to shut the dome in order to preserve the telescope This project will convert the dome into a fully automated system There are a few constraints that will affect the design There is an existing dome two existing dome motors and three sensors that have to be used in the design The subsystem has to be able to work in all types of weather situations taking place in Logan Utah A team of electrical engineering students from Utah State University have developed the design and some preliminary implementation to achieve the overall goal of a stand alone fully functional observatory system 3 0 Project Organization 3 1 Engineering Team Members of the Observatory team are enrolled and active in a University Electrical Mechanical Engineering course designed to specialize in Space Systems Engineering As team members provide personal initiative and experience to the group the project progresses and members benefit from one another The Dome Operations Sub group works with dome operations including motors PLC interface and power issues The Weather Sub group relates to design pertaining to weather related sensors The Telescope Sub group deals with aspects of interfacing an automated telescope with computer controlling software The team works together in designing and testing to plan interfacing and eventual system implementation 3 2 Semester Timeline Each of the three groups created a timeline to outline key goals and accomplishment
55. s the user to manually move the telescope This allows other objects not on the star map to be viewed remotely This is done using the remote hand box module of the software This is shown in Figure 20 The CCD camera that is used is also controllable with the software The exposure time quality levels of individual pictures that are compiled together and the number of pictures that are compiled for a final photograph are all remotely controllable The Envisage module of the software that controls the camera is shown in Figure 21 50 AutoStar Menu Align Object Automatic Event Guided Tour Glossary Utilities Setup s Enter Mode Goto Scroll Up Scroll Dn Help Slew Rate Focuser Speed Focus In Focus Out Guide Ctr Find Slew Slow Fast Speech Com Port Network Address Port Enable Connect PCI COM COM3 Connect Figure 20 Remote Handbox 12 AutoStar Envisage File Settings About ob 100 Mono Save Proc Dark Deep Sky 50 Sub CCD Temp Start Num Images Image Qual Jpeg Normal Operation Count Down Image Process Deep Sky Preview Long exp 0 0113 4 Auto exp iv LIVE DSI Image Files Stats Telescope psi Image Files ThorsHelmet ae Auto Shadow Contrast Enhance Magic Eye Focus Max 0 69 Figur
56. se of a hard drive failure the system is saved and can be quickly brought back online with little effort 8 2 Dome Instructions A set of instructions will be written for every sub system of the observatory which will give the user step by step guidance of what to do under certain circumstance The circumstances that will be addressed are for the observatory dome subsystem and will address the following 61 issues Power Failure Laser Failure CdS Sensing System Failure PLC Failure and Computer Failure There is also instructions for Updating the Website Power Failure In the event of power failure the UPS system should allow enough power to shut the shutter If a power failure does occur maintenance needs to check to make sure that the shutter did automatically shut when the power comes back on maintenance needs to check all equipment realign dome and telescope if needed and continue any observations that may have been running at the time of the outage Laser Failure If the laser quits working then maintenance should Check power to the laser using a volt meter check connection to laser If the previous two items did not fix the issue then the laser should be replaced and the new laser should be mounted and aligned CdS Sensing System Failure If the sensor circuit fails to work then maintenance should check the power to the circuit for 5V if there is power to the circuit then maintenance will have to start the excruciatingly pain
57. stem Dome follows telescope sufficiently Maintain telescope field of view 360 degree limits e Feedback maintains telescope viewable tolerance 30 degrees e Sensor system with greater than 10 degree resolution e Panel and contained equipment location e Centralized panel safely controls equipment Reduce electromagnetic interference Soft Start e Extend motor life Better more controllable motor implementation e Safety NEC National Electrical Code Requirements Emergency stop and disconnection features 5 3 Detailed Design Schematics and Layout 5 3 1 Motor Sensor 5 3 1 1 Motor The motor that is currently rotating the dome is a single phase 2 9 Amp Inductor motor which is shown in Figure 8 32 Figure 8 Induction Motor Inductor motors are designed to run for longer intervals instead of shorter intervals so in order to prolong the life of the motor a soft starter is going to be implemented The soft starter allows the motor to be gradually ramped up to full speed by limiting the initial voltage between 30 80 while gradually raising it to full voltage over an adjustable range of one to five seconds figure 4 shows the Voltage vs Ramp up times The soft starter that has been selected is the as shown in Figure 9 which gives the above stated functionality The soft starter will be wired up according to the schematic shown in Figure 11 instead of using buttons for the stop and st
58. tem is shown in Figure 19 below The project included selecting the main components of the system designing the connections between components to ensure that data was held intact throughout the entire system implementing the design troubleshooting the design to make it work properly and testing the final subsystem to make sure everything works 48 Handbox Control Telescope Control AutoStar Suite TELESCOPE Meade LX200R Vibration Control ij DeepSky Imager II Figure 19 Telescope System Block Diagram 6 1 2 Location Operating Conditions The location of the telescope is in a dome on the roof of the Engineering Lab Building and the control computer is currently located in the room below the dome The dome currently is operated by switches located inside the dome that activate motors to open close and rotate the dome These conditions require that someone be physically present to move the dome with the telescope which means that total remote access of the telescope subsystem is not possible at this time The fact that the telescope and computer are in different rooms has required that the cables interfacing the telescope and camera to the computer to be at least 7 62 meters long 6 2 Design Constraints 6 2 1 Operating Software The Rocky Mountain Space Grant Observatory was designed to be able to be used by the public who will not have access to the telescope itself This r
59. tips or the wind gets above 40 miles per hour If any of theses weather conditions occur the dome will close and continue to read the sensors to see when it is okay to open the dome again 4 1 6 Sensor Set Up of the sensors were mounted on an anchored tripod on top of the EL building at USU The sensors were then hooked up to the board with the circuitry found in figure 1 which is 14 connected to a wire to the PLC The board was then encapsulated in a water tight box to keep it protected from the elements 4 1 7 Sensor Power To power the sensors a 120VAC to 12VDC transformer was used The actual output of the transformer was 18VDC In order to get the desired 12VDC for the HMP45C Temperature Humidity Sensor and 5VDC for the TE525 Rain Bucket two simple voltage regulators were used LM7805 was used to get the SVDC and the LM7812 was used to get the 12VDC Below are the schematics for the voltage regulator circuits 18V org 5V tu LM7805 o pin 2 goes to ground o Figure 4 5 Volt voltage Regulator 18V out 12V LM7812 pin 2 goes to ground o Figure 5 12 Volt Voltage Regulator The capacitors are used to dampen any voltage spikes 4 2 Software The PLC uses RSLogix5 software to write the control program for the PLC RSLogix5 is a Windows based ladder logic programming tool It visually shows the ladder program as well as contains several other tools to make the programming
60. uld like the link added to on the main site manager page Place the curser where you would like the link to be and select the link button on the left side of the tool bar This will bring up four options for the type of links you can select from Your pages will create a new page in google pages and link it to your current page Your files allows you to browse for what you would like to add to the page i e a word document photo or other file Web address would create a link to another website Email address will save a link to an email address that when clicked on will open a generic email editor The text to display box at the top of the link editor window if where you enter the title you would like to view on the webpage For example if you are creating contact information with email address you would put John Smith as the text to display and john smith gmail com as the email address link Always remember to click on the publish button in the upper left part of the screen to save any changes If you forget to do this it will display unpublished or in revision next to the page in the main site manager page as a reminder 63 9 0 Conclusion The Rocky Mountain Space Grant currently owns a dome and telescope located on the roof of the Engineering Laboratory building The overall objective is to design a system that allows for remote access from a Personal Computer to control the telescope and have th
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