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RoboteQ AX1500 Computer Hardware User Manual

1. Location Description Active after 00 Input control mode Reset 01 Motor Control mode and Closed Loop Feedback type Reset or FF 02 Amps limit Reset or AFF A03 Acceleration Reset or AFF 04 Input Switch function Reset or FF 05 reserved 06 Joystick Deadband or Analog Deadband Reset or FF 07 Exponentiation on channel 1 Instant 08 Exponentiation on channel 2 Instant 09 Reserved AOA Left Right Adjust Reset or AFF AOB Encoder 1 Time Base when Encoder Present Reset or AFF AOC Encoder 2 Time Base when Encoder Present Reset or AFF AOD Reserved AOE Encoder Distance Divider when Encoder Present Reset or AFF AOF Gain Integral for PID Reset or AFF 10 Gain Diff for PID Reset or AFF 11 Gain Prop for PID Reset or FF 12 Joystick Center 1 MS nstan 13 Joystick Center 1 LS nstan 14 Joystick Center 2 MS nstan 15 Joystick Center 2 LS nstan 16 Joystick Min 1 MS nstan 17 Joystick Min 1 LS nstan 18 Joystick Min 2 MS nstan 19 Joystick Min 2 LS nstan MA Joystick Max 1 MS nstan A1B Joystick Max 1 LS nstan 134 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Accessing amp Changing Configuration Parameter in Flash TABLE 22 Configuration parameters in Flash Location Description Active after AIC Joystick Max 2 MS Instant A1D Joystick Max 2 LS Instant AFO Amps Calibration Parameter 1 Reset AFI Amps Calibration Parameter 2 Res
2. AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ SECTION 1 Important Safety Warnings Read this Section First The AX1500 is a high power electronics device Serious damage including fire may occur to the unit motors wiring and batteries as a result of its misuse Transistors may explode and require the use of safety glasses when operated in direct view Please review the User s Manual for added precautions prior to applying full battery or full load power This product is intended for use with rechargeable batteries Unless special precautions are taken damage to the controller and or power supply may occur if operated with a power supply alone See Power Regeneration Consid erations on page 35 of the Users Manual Always keep the controller connected to the Battery Use the Power Control input to turn On Off Avoid Shorts when Mounting Board against Chassis Use precautions to avoid short circuits when mounting the board against a metallic chassis with the heat sink on or removed See Attaching the Controller Directly to a Chassis on page 183 Do not Connect to a RC Radio with a Battery Attached Without proper protection a battery attached to an RC Radio may inject its voltage directly inside the controller s sensitive electronics See Beware of Motor Runaway in Improperly Closed Loop Wiring or polarity errors between the feedback device and motor in position
3. IRoboteQ 9A 9B Least Significant Byte These two 32 bit 4 bytes registers are used to store the desired destination when the controller is used in position mode These registers should always be set using the mailbox mechanism described above See Using the Encoder to Track Position on page 77 for a complete description of the position mode Distance 1 and 2 Address 9C Channel 1 9D Channel 2 These registers contain a signed 8 bit value 127 to 127 that represents the distance between the current counter position and the desired destination This number is com puted using a formula described in section Using the Encoder to Track Position on page 77 Speed 1 and 2 Address 9E Channel 1 8F Channel 2 These registers contain a signed 8 bit value 127 to 127 that represents the motor speed relative to a maximum speed which in turn depends on the number of encoder counts and time base settings as described in Using the Encoder to Measure Speed on page 76 Time Base 1 and 2 Address A2 Channel 1 A3 Channel 2 These registers contain the timing information for measuring the speed See Using the Encoder Module to Measure Distance on page 76 for a detailed description Encoder Threshold Address A4 This register contains a value that is used to detect a logic level 1 vs a 0 at any of the 4 encoder input lines The voltage threshold is computed as follows Voltage
4. Important Warning If there is a polarity mismatch the motor will turn in the wrong direction and the position will never be reached The motor will turn continuously with no way of stopping it other than cutting the power or hitting the Emergency Stop button Determining the right polarity is best done experimentally using the Roborun utility see Using the Roborun Configuration Utility on page 161 and following these steps 1 2 Disconnect the controller s Motor Power Vmot terminals Configure the controller in Position Mode using the PC utility Loosen the sensor s axle from the motor assembly Launch the Roborun utility and click on the Run tab Click the Start button to begin communication with the controller The sensor values will be displayed in the Anat and Ana2 boxes Move the sensor manually to the middle position until a value of O is measured using Roborun utility Verify that the motor sliders are in the 0 Stop position Since the desired posi tion is 0 and the measured position is 0 the controller will not attempt to move the motors The Power graph on the PC must be 0 Apply power to the Motor Power input Vmot terminals The motor will be stopped With a hand ready to disconnect the Motor Power cable or ready to press the Pro gram and Set buttons at the same time Emergency Stop SLOWLY move the sensor off the center position and observe the motor s direction
5. Click on the Create button and save the new customized object file Click on the Done button to exit the program AX1500 Motor Controller User s Manual 179 Using the Roborun Configuration Utility RoboteQ 8 Install the new object file in the controller using the Roborun utility 180 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Mechanical Dimensions SECTION 15 Mechanical Specifications This section details the mechanical characteristics of the AX1500 controller Mechanical Dimensions The AX1500 is delivered as an assembled and tested Printed Circuit Board The board includes connectors for direct connection to the Optical Encoders and to the Radio Joy stick or microcomputer on one side On the other side can be found Fast on tabs for high current connection to the batteries and motors A heat sink is mounted beneath the board to help with the heat dissipation of the Power Transistors s Lin in 14 5mm E i a 0 47 0 1 1 27mm 0 25 6 35mm rd 1 15 29 2mm _ 0 68 17 2 mm FIGURE 100 AX1500 side view and dimensions AX1500 Motor Controller User s Manual 181 Mechanical Specifications IRo b oteQ 4 20 106 7mm 0 15 3 8mm 0 15 3 8mm 4 3 8mm N 3 8mm cemi e 1 25
6. The screen shown in Figure 93 is used to set the Proportional Integral and Differential gains needed for the PID algorithm These PID gains are loaded after reset and apply to both channels Gains can be changed individually for each channels and on the fly using RS232 commands These parameters are used in the Position mode see page 81 and the Closed Loop speed mode see page page 93 Encoder Setting and Testing Extensive diagnostic calibration setting and testing support is provided in the Roborun PC utility Basic instructions on how to install and run the PC utility can be found in Using the Roborun Configuration Utility on page 161 Once the utility is up and running and the controller found and identified click on the Encoder tab to bring up the Encoder configuration and setup screen show in Figure 94 below 168 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Encoder Setting and Testing Controls Power Settings R C Ana Specific Close Loop RC Out Run Console r Configuration Parameters m Encoder 1 Status Digital Level Threshold Measured Rel Speed 9 Dist fo Q 25 RPM Equivalent 0 Time Base PPR Switch1 E Switch2 E Q a B 200 Cir Counter Value 9 Max RPM 2188 s 200 r Encoder 2 Status Ma DER E Measured Rel Speed 0 Dist 0 Distance Divider EEE veer 10 marian 8 Switch3 J Switchs E Parame
7. lRoboteQ Using the Encoder to Track Position A simple procedure is included in the Roborun PC utility to easily determine and set these parameters For information the exact formula is shown below Measured Speed Value RPM PPR 4 Time Base 1 256 60 1000000 or Measured Speed Value RPM PPR Time Base 1 58593 75 Example a motor spinning at 1 000 RPM with an encoder with 200 Pulses per Revolution and a Time Base set at 4 will produce the following measurement 1000 200 4 1 58593 75 17 The same formula modified to show the actual RPM at a given Measure Speed Value is as follows RPM Measured Speed Value 60 1000000 PPR 4 256 Time Base 1 or RPM Measured Speed Value 58593 75 Time Base 1 PPR In our example a measured speed value of 127 corresponds to the following measurable max actual RPM values RPM at Max Measurable Speed Value 127 58593 75 4 1 200 7441 RPM A measured speed value of 1 corresponds to the following measurable min actual RPM values RPM at Min Measurable Speed Value 1 58593 75 4 1 200 58 6 RPM The Roborun Utility automatically makes the above calculations when setting up the encoder Important Notice The time base value should not exceed 63 so that a new speed value can be mea sured at every 16ms loop The roborun utility automatically limits the time base value that can be entered Using the
8. 24 4 32 5 40 6 46 7 54 Exponentiation on Channel 1 and Channel 2 Address Access Effective 08 Channel 1 09 Channel 2 Read Write Instantly 138 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Accessing amp Changing Configuration Parameter in Flash This parameter configures the transfer curve that is applied the input command Bit 7 0 Definition See pages 0 Linear no exponentiation default page 109 1 strong exponential 2 normal exponential 3 normal logarithmic 4 strong logarithmic Left Right Adjust Address AOB Access Read Write Effective After Reset or AFF This parameter configures the compensation curve when motors are spinning in one direc tion vs the other Bit 7 0 Definition See pages 0 1 6 5 25 4 5 0 75 page 47 7 no adjustment default 8 D E 0 75 4 5 5 25 Default Encoder Time Base 1 and 2 Address AOB Encoder 1 0C Encoder 2 Access Read Write Effective After Reset or FF These parameters are the Encoder Time base values that are loaded after the controller is reset or powered on Time Bases are used to determine rotation speed depending on the Encoder s resolution Time Bases can be changed at Runtime using separate commands see page 142 Time Base values are integer number from 0 to 63 These paramete
9. 3 A amp B position 4 A amp B separate speed closed loop 5 A amp B mixed speed closed loop 6 A speed close loop B position 6 3 Reserved 6 Ch1 Feedback type 0 Analog page 93 1 Encoder page 81 7 Ch2 Feedback type 0 Analog 1 Encoder Amps Limit Address A02 Access Read Write Effective After Reset or AFF This parameter configures the controller s Amps limit Note that this limits the amps flow ing out of the power supply Current flowing through the motors may be higher Bit Definition See pages 3 0 Coarse Amps 0 75A page 42 1 11 25A 2 15A 3 18 75A 4 22 5A 5 26 25A default 6 30A 7 4 Fine Amps Mutliply this number by 0 25 and sub stract result from the Coarse Amps value 136 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ Accessing amp Changing Configuration Parameter in Flash Acceleration Address 03 Access Read Write Effective After Reset or FF This parameter configures the rate at which the controller internally changes the command value from the one it was to the one just received Bit 7 0 Definition 0 very slow 1 slow 2 medium slow default 3 medium 4 fast 5 fastest See pages See Programmable Acceleration on page 45 for complete list of acceptable values Input Switches Function Address 04 Access Read Write Effective After Reset or FF T
10. 31 75mm E AEREE EA A OF 2 00 OF 50 8mm O C Ok 2 10 4 20 p e Ok 53 4mm 106 7mm Cy I o fee pe OR Sr EE I BF baer 0 120 O E 50 0mm n 0550 a Som O ROBOTEG AX1500 2005 Rev 12 1 10 3 0 15 0 15 3 8mm 74 0mm O7 3 8mm Y EEREN 0 15 3 8mm 0 15 3 8mm 2 915 74 0mm FIGURE 101 AX1500 top view and dimensions Mounting Considerations The AX1500 s heatsink is located at the bottom of the board This requires therefore that the board be mounted with spacers that are at minimum 0 6 15mm 0 6 15mm or longer spacer FIGURE 102 Use spacers to provide clearance for heatsink Thermal Considerations The AX1500 is equipped with an aluminum heatsink beneath the power transistors ensur ing sufficient heat dissipation for operation without a fan in most applications When mounting the board and if current is expected to be above 15A on average ensure that there can be a natural or forced convection flow to remove the heat Mounting the 182 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Attaching the Controller Directly to a Chassis board against a vertical surface as shown in the figure below will ensure a better natural convection flow and is therefore recommended Q Q f He FIGURE 103 Mount the controller against a vertical surface to maximize convection flow p For hi
11. 92 Counter 2 bits 15 to 8 93 Counter 2 LSB bits 7 to 0 94 Destination Register 1 MSB bits 31 to 24 95 Destination Register 1 bits 23 to 16 4 bytes Full 96 Destination Register 1 bits 15 to 8 97 Destination Register 1 LSB bits 7 to 0 AX1500 Motor Controller User s Manual 149 lRoboteQ TABLE 28 Encoder Registers Address Parameter Description Size Access 98 Destination Register 1 MSB bits 31 to 24 99 Destination Register 1 bits 23 to 16 4 bytes Full OA Destination Register 1 bits 15 to 8 OB Destination Register 1 LSB bits 7 to 0 9C Distance 1 when Position Mode enabled 1 byte Ful 8D Distance 2 when Position Mode enabled 1 byte Ful 86 Speed 1 1 byte Ful 87 Speed 2 1 byte Ful A2 Time Base for speed computation of Encoder 1 Multiply 1 byte Ful this number by 256us to obtain the actual Time Base period A3 Time Base for speed computation of Encoder 2 Multiply 1 byte Ful this number by 256us to obtain the actual Time Base period A4 Encoder threshold level see Voltage Levels Thresholds 1 byte Ful and Limit Switches on page 72 A5 Distance divider 1 byte Ful A6 Mode Selection 1 byte Limited Important Warning Do not alter any other area locations as this may cause program execution failure inside the encoder module Register Description Encoder Hardware ID code Address 84 Retur
12. Activating the Accessory Outputs on page 110 for more information When the controller is used in RS232 mode this output can be turned On and Off using the C On and e Off command strings See Controller Commands and Queries on page 128 for more information AX1500 Motor Controller User s Manual 55 Connecting Sensors and Actuators to Input Outputs RoboteQ Important warning Overvoltage spikes induced by switching inductive loads such as solenoids or relays will destroy the transistor unless a protection diode is used Connecting Switches or Devices to Input E Input E is a general purpose digital input This input is only available if no encoder module is present and is active when in the RS232 and Analog modes In R C mode this line is used as the radio channel 3 input Input E is a high impedance input with a pull up resistor built into the controller Therefore it will report an On state if unconnected and a simple switch as shown on Figure 24 is nec essary to activate it 5V Out 14 50kOhm Input E 8 10kOhm 50kOhm Internal Buffer Ground 5 FIGURE 24 Switch wirings to Input E The status of Input E can be read in the RS232 mode with the i command string The con troller will respond with three sets of 2 digit numbers The status of Input E is contained in the first set of numbers and may be 00 to indicate an Off state or 01 to indicate an On state Remember th
13. June 1 2007 RoboteQ Poweron SECTION 10 Normal and Fault Condition LED Messages This section discusses the meaning of the various messages and codes that may be dis played on the LED display during normal operation and fault conditions Power On LED The AX1500 features an LED that comes on whenever the board is powered on When lit this LED indicates that the on board DC DC converter is functioning It provides no infor mation regarding the controller s operation Diagnostic LED The AX1500 features a single diagnostic LED which helps determine the controller s oper ating mode and signal a few fault conditions The LED is located near the edge of the board next to he 15 pin connector Normal Operation Flashing Pattern Upon normal operation 1 second after power up the LED will continuously flash one of the patterns below to indicate the operating mode A flashing LED is also an indication that the controller s processor is running normally AX1500 Motor Controller User s Manual 99 Normal and Fault Condition LED Messages RoboteQ BERR EEEEEREREE RC Mode BERBER S232 Mode No Watchdog EERE RS232 Mode with Watchdog BREE EEREEEREREERR Analog Mode FIGURE 59 Status LED Flashing pattern during normal operation Output Off Fault Condition The controller LED will tun On solid to signal that the output stage is off as a result of a any of the recoverable conditions listed below BEREEEEEEEE
14. RC Activated Switch Power Control RC1 RxData O TxData Controller RC2 InputF Computer RxData TxData FIGURE 84 External circuit required for RS232 to RC switching The switching sequence goes as follows Upon controller power on with Radio off or Radio on with RC ch3 off e Controller runs in RC mode must be configured in RC mode e Computer must send 10 consecutive Carriage Returns Controller enters RS232 mode Controller is on Radio urns On with RC ch3 On e Controller is reset returning to RC mode e Controller will output the continuous parameter strings on the RS232 output Com puter thus knows that RC mode is currently active Computer sends Carriage Return strings to try to switch controller back in RS232 mode Since the RS232 line is not connected to the controller mode will not change AX1500 Motor Controller User s Manual 155 RoboteQ Controller is on Radio is turned Off or Radio On with RC ch3 Off e Relay deactivates RS232 is now connected to shared input e String of Carriage Returns now received by controller e Computer looks for OK prompt to detect that the RS232 mode is now active Note Wait 5 seconds for the capacitor to discharge before attempting to switch to RC mode if doing this repeatedly Controller will not reset otherwise Analog and R C Modes Data Logging String Format When the cont
15. e Closed Loop Operation e Software updating e and much more AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ SECTION 3 AX1500 Motor Controller Overview Congratulations By selecting Roboteg s AX1500 you have empowered yourself with the industry s most versatile and programmable DC Motor Controller for mobile robots This manual will guide you step by step through its many possibili ties Product Description The AX1500 is a highly configurable microcomputerbased dual channel digital speed or position controller with built in high power drivers The controller is designed to interface directly to high power DC motors in computer controlled or remote controlled mobile robotics and automated vehicle applications The AX1500 controller can accept speed or position commands in a variety of ways pulse width based control from a standard Radio Control receiver Analog Voltage commands or RS 232 commands from a microcontroller or wireless modem The controller s two channels can be operated independently or can be combined to set the forward reverse direction and steering of a vehicle by coordinating the motion on each side of the vehicle In the speed control mode the AX1500 can operate in open loop or closed loop In closed loop operation actual soeed measure ments from tachometers are used to verify that the motor is rotating at the desired speed and direction and to adjust the powe
16. 11 Set the controller parameter to the desired Closed Loop Speed mode using the Roborun utility AX1500 Motor Controller User s Manual 95 Closed Loop Speed Mode RoboteQ Adjust Offset and Max Speed For proper operation the controller must see a 0 analog speed value 2 5V voltage on the analog input To adjust the 0 value when the motors are stopped use the Roborun utility to view the analog input value while the tachometer is not turning Move the 0 offset potentiometer until a stable O is read This should be right around the potentiometer s middle position The tachometer must also be calibrated so that it reports a 127 or 127 analog speed value 5V or OV on the analog input respectively when the motors are running at the max imum desired speed in either direction Since most tachometers will generate more than 2 5V a 10kOhm potentiometer must be used to scale its output To set the potentiometer use the Roborun utility to run the motors at the desired maxi mum speed while in Open Loop mode no speed feedback While the tachometer is spin ning adjust the potentiometer until the analog speed value read is reaching 126 Note The maximum desired speed should be lower than the maximum speed that the motors can spin at maximum power and no load This will ensure that the controller will be able to eventually reach the desired speed under most load conditions Important Warning It is critically im
17. 179 B3 45 211 D3 13 243 F3 108 148 94 76 180 B4 44 212 D4 12 244 F4 107 149 95 75 181 B5 43 213 D5 11 245 F5 106 150 96 74 182 B6 42 214 D6 10 246 F6 105 151 97 73 183 B7 41 215 D7 9 247 F7 104 152 98 72 184 B8 40 216 D8 8 248 F8 103 153 99 71 185 B9 39 217 D9 7 249 F9 102 154 9A 70 186 BA 38 218 DA 6 250 FA 101 155 9B 69 187 BB 37 219 DB 5 251 FB 100 156 9C 68 188 BC 36 220 DC 4 252 FC 99 157 9D 67 189 BD 35 221 DD 3 253 FD 98 158 9E 66 190 BE 34 222 DE 2 254 FE 97 159 9F 65 191 BF 33 223 DF 1 255 FF AX1500 Motor Controller User s Manual 159 lRoboteQ 160 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ SECTION 14 Using the Roborun Configuration Utility A PC based Configuration Utility is available free of charge from Roboteq This pro gram makes configuring and operating the AX1500 much more intuitive by using pull down menus buttons and sliders The utility can also be used to update the controller s software in the field as described in Updating the Controller s Soft ware on page 178 System Requirements To run the utility the following is need e PC compatible computer running Windows 98 Me 2000 XP or Vista e An unused serial communication port on the computer with a 9 pin female connector e An Internet connection for downloading the latest version of the Roborun Utility or the Controller s
18. Linear default Exponential Weak Exponential Strong 100 80 60 z 4 Command Input 20 40 60 80 20 Deadband 40 60 80 100 Reverse FIGURE 19 Exponentiation curves The AX1500 is delivered with the linear curves selected for both joystick channels To select different curves the user will need to change the values of E channel 1 and F channel 2 according to the table below Refer to the chapter Configuring the Controller using the Switches on page 171 or Using the Roborun Configuration Utility on page 161 for instructions on how to program parameters into the controller TABLE 5 Exponent selection table Exponentiation Parameter Value Selected Curve EorF 0 Linear no exponentiation default value EorF 1 strong exponential EorF 2 normal exponential EorF 3 normal logarithmic EorF 4 strong logarithmic Left Right Tuning Adjustment By design DC motors will run more efficiently in one direction than the other In most situ ations this is not noticeable In others however it can be an inconvenience When operat ing in open loop speed control the AX1500 can be configured to correct the speed in one direction versus the other by as much as 10 Unlike the Joystick center trimming tab that AX1500 Motor Controller User s Manual 47 General Opera
19. Module The first two are used to generate an analog voltage ranging from OV to 5V depending on their position They will report an absolute position information at all times Optical encoders report incremental changes from a reference which is their initial position when the controller is powered up or reset Using Optical Encoders in this mode is possi ble but requires special handling that is described in Figure Using the Encoder to Track Position on page 77 Sensor Mounting Proper mounting of the sensor is critical for an effective and accurate position mode opera tion Figure 48 shows a typical motor gear box and sensor assembly Position Feedback Position Sensor FIGURE 48 Typical motor potentiometer assembly in Position Mode The sensor is composed of two parts e abody which must be physically attached to a non moving part of the motor assem bly or the robot chassis and e anaxle which must be physically connected to the rotating part of the motor you wish to position A gear box is necessary to greatly increase the torque of the assembly It is also necessary to slow down the motion so that the controller has the time to perform the position control algorithm If the gearing ratio is too high however the positioning mode will be very slug gish A good ratio should be such that the output shaft rotates at 1 to 10 rotations per second 60 to 600 RPM when the motor is at full speed 82 A
20. O6 20 RX Data 2 O2 Data Out O7 10 O TX Data 30 3 Data ln O 8 nO 40 O4 Og 120 GND 5 O5 GND FIGURE 80 PC to AX1500 RS232 cable connector wiring diagram Extending the RS232 Cable The AX1500 is delivered with a 4 foot cable adapter which may be too short particularly if you wish to run and monitor the controller inside a moving robot RS232 extension cables are available at most computer stores However you can easily build one using a 9 pin DB9 male connector a 9 pin DBY female connector and any 3 wire cable These components are available at any electronics distributor A CAT5 network cable is recommended and cable length may be up to 100 30m Figure 81 shows the wiring diagram of the extension cable AX1500 Motor Controller User s Manual 123 Serial RS 232 Controls and Operation lRoboteQ DB9 Female DB9 Male 10 Gi O6 6 0O RX Data 2 OQ 0O Data Out O7 70 TX Data 3 O O Dataln O8 8O 40 O4 Og 90 GND 5 O gt ns GND FIGURE 81 RS232 extension cable connector wiring diagram Communication Settings The AX1500 serial communication port is set as follows 9600 bits s 7 bit data 1 Start bit 1 Stop bit Even Parity Communication is done without flow control meaning that the controller is always ready to receive data and can send data at any time These settings cannot be changed You must therefore adapt the communication setting in your P
21. R C cable for connection to a PC DB9 Female DB15 Male To PC To Controller 1 10 O O6 20 2 RX Data 2 O 0O RS232 Data Out O7 00 3 30 O R CCh1 Os no 4 40 Oo n_ R CCh2 Os 120 5 GND 5 GND 13 R C GND 14 Nooo O Z o R C 5V 15 0O 8 e FIGURE 74 Modified R C cable with RS232 output for data logging to a PC 112 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Mode Description SECTION 12 Analog Control and Operation This section describes how the motors may be operated using analog voltage commands Mode Description The AX1500 can be configured to use a 0 to 5V analog voltage typically produced using a potentiometer to control each of its two motor channels The voltage is converted into a digital value of 127 at OV O at 2 5V and 127 at 5V This value in turn becomes the com mand input used by the controller This command input is subject to deadband threshold and exponentiation adjustment Analog commands can be used to control motors sepa rately one analog input command for each motor or in mixed mode Important Notice The analog mode can only be used in the Closed Loop speed or position modes when Optical Encoders are used for feedback Position potentiometers or tachome ters cannot be used since there is only one analog input per channel and since this this input will be connected to the command potentiometer AX1500 Motor Controller Use
22. Testing and Setting Using the PC Utility 153 Automatic Switching from RS232 to RC Mode 155 Analog and R C Modes Data Logging String Format 156 Data Logging Cables 156 Decimal to Hexadecimal Conversion Table 157 SECTION 14 Using the Roborun Configuration Utility 161 System Requirements 161 Downloading and Installing the Utility 161 Connecting the Controller to the PC 162 Roborun Frame Tab and Menu Descriptions 163 Getting On Screen Help 164 Loading Changing Controller Parameters 164 Control Settings 165 Power Settings 166 Analog or R C Specific Settings 167 Closed Loop Parameters 168 Encoder Setting and Testing 168 Encoder Module Parameters Setting 169 Exercising the Motors 170 Viewing Encoder Data 170 Running the Motors 170 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ SECTION 15 Logging Data to Disk 173 Connecting a Joystick 174 Using the Console 174 Viewing and Logging Data in Analog and R C Modes 176 Loading and Saving Profiles to Disk 176 Operating the AX1500 over a Wired or Wireless LAN 176 Updating the Controller s Software 178 Updating the Encoder Software 178 Creating Customized Object Files 179 Mechanical Specifications 181 Mechanical Dimensions 181 Mounting Considerations 182 Thermal Considerations 182 Attaching the Controller Directly to a Chassis 183 Precautions to observe 184 Wire Dimensions 185 Weight 185 AX1500 Motor Controller User s Manual lRoboteQ
23. Threshold 5V Register Value 255 See Voltage Levels Thresholds and Limit Switches on page 72 for a detailed description Distance Divider Address A5 This registers contain the divider ratio that is applied to the difference between the current position and destination See Using the Encoder Module to Measure Distance on page 76 for a detailed description 152 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Counter Read Data Format Counter Read Data Format When receiving a counter read query the encoder module will output the value of its 32 bit counter If all 32 bit are sent this would require 8 ASCII digits to represent the value A 32 bit counter can store over 2 billion counts in each direction In practice it will be rare that counts will be so large than only a partial number of the counter s bits will be signifi cant at any given time In order to create a more efficient data stream on the controller s serial port a simple com pression technique is implemented The scheme eliminates all of the counter s most signif icant bits if they are at O for a positive count number or F for a negative count number For example if the counter value is Hex 00000015 the value 15 will be returned after a counter query For negative numbers a count value of 5 which is FFFFFFFB in hex the response to the query will be B To distinguish between positive and ne
24. a 0 to 5V positive voltage as its input the circuit shown in Figure 29 must be used between the controller and the tachometer a 10kOhm potentiom eter is used to scale the tachometer output voltage to 2 5V max reverse speed and 2 5V max forward speed The two 1kOhm resistors form a voltage divider that sets the idle voltage at mid point 2 5V which is interpreted as the zero position by the controller The voltage divider resistors should be of 1 tolerance or better To precisely adjust the 2 5V midpoint value it is recommended to add a 100 ohm trimmer on the voltage divider With this circuitry the controller will see 2 5V at its input when the tachometer is stopped OV when running in full reverse and 5V in full forward 1kOhm Internal Resistors and Converter Max Speed Adjust 10kOhm pot 47kOhm Zero Adjust 100 Ohm pot C 10kOhm 47kOhm 1kOhm FIGURE 29 Tachometer wiring diagram The tachometers can generate voltages in excess of 2 5 volts at full speed It is important therefore to set the potentiometer to the minimum value cursor all the way down per this drawing during the first installation Since in closed loop control the measured speed is the basis for the controller s power out put i e deliver more power if slower than desired speed less if higher an adjustment and calibration phase is necessary This procedure is described in Closed Loop Speed Mode on page 93 TABLE 10 Analo
25. as pin 4 Brown Cable Length and Noise Considerations Cable should not exceed one 3 one meter to avoid electrical noise to be captured by the wiring A ferrite core filter must be used for length beyond 2 60 cm For longer cable length use an oscilloscope to verify signal integrity on each of the pulse channels and on the power supply Encoder Ferrite Core FIGURE 41 Use ferrite core on cable length beyond 2 or 60cm AX1500 Motor Controller User s Manual 71 Installing Connecting and Using the Encoder Mod lRoboteQ Important Warning Excessive cable length will cause electrical noise to be captured by the controller and cause erratic functioning that may lead to failure In such situation stop operation immediately Motor Encoder Polarity Matching When using the Encoder module for closed loop speed control it is imperative that when the motor is turning in the forward direction the counter increments its value and a posi tive speed value is measured Using the PC utility it is possible to exercise the motors and view the encoder readings See Encoder Testing and Setting Using the PC Utility on page 79 If the Encoder counts backwards when the motor moves forward correct this by either 1 Swapping Channel A and Channel B on the encoder connector This will cause the encoder module to reverse the count direction or 2 Swapping the leads on the motor Th
26. first one The formula below gives the pulse frequency at a given RPM and encoder resolution in Pulses per Revolution Pulse Frequency in Hz RPM 60 PPR 4 Example a motor spinning at 10 000 RPM max with an encoder with 200 Pulses per Rev olution would generate 10 000 60 200 4 133 3 kHz which is well within the 250kHz maximum supported by the encoder module An encoder with a 200 Pulses per Revolutions is a good choice for most applications A higher resolution will cause the counter to count faster than necessary and possibly reach the encoder module s maximum frequency limit An encoder with a much lower resolution will cause speed to be measured with less preci sion Installing the Encoder Module The Encoder module is available in kit form for installation by the user on top of the AX2550 controller 1 Remove power FIGURE 37 Encoder Module for AX2550 1 With the power removed remove the controller s face plate and slide off the cover AX1500 Motor Controller User s Manual 69 Installing Connecting and Using the Encoder Mod RoboteQ 2 Carefully insert the encoder module on top of the two headers present on the control ler s main board and shown in Figure 38 Beware that the two matting connectors are pre cisely aligned 3 The encoder module will be held in place by the hea ders and connectors For use in a Ss FIGURE 38 Position of Encoder Module on Controller
27. low impedance motors 44 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ Programmable Acceleration Programmable Acceleration When changing speed command the AX1500 will go from the present speed to the desired one at a user selectable acceleration This feature is necessary in order to minimize the surge current and mechanical stress during abrupt speed changes This parameter can be changed by using the controller s front switches or using serial com mands When configuring the controller using the switches see Configuring the Control ler using the Switches on page 171 acceleration can be one of 6 available preset values from very soft 0 to very quick 6 The AX1500 s factory default value is medium soft 2 When using the serial port acceleration can be one of 24 possible values selectable using the Roborun utility or entering directly a value in the MCU s configuration EEPROM Table 4 shows the corresponding acceleration for all Switch and RS232 settings Numerically speaking each acceleration value corresponds to a fixed percentage speed increment applied every 16 milliseconds The value for each setting is shown in the table below TABLE 4 Acceleration setting table Acceleration Acceleration Setting Using Setting Using Acceleration per Time from 0 to RS232 Switches 16ms ma
28. or closed loop position mode may cause the controller to runaway with no possibility to stop it until power is turned off AX1500 Motor Controller User s Manual 13 Important Safety Warnings lRoboteQ AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ SECTION 2 AX1 500 Quick Start This section will give you the basic information needed to quickly install setup and run your AX1500 controller in a minimal configuration What you will need For a minimal installation gather the following components One AX1500 Controller and its provided cables 12V to 40V high capacity high current battery One or two brushed DC motors One R C to DB15 connector provided Miscellaneous wires connectors fuses and switch Locating the Connectors Take a moment to familiarize yourself with the controller s connectors AX1500 Motor Controller User s Manual 15 AX1500 Quick Start RoboteQ The front side shown in Figure 1 contains the Power Status LED and the 15 pin connector to the R C radio joystick or microcomputer as well as connections to optional switches and sensors Connector to Receiver Controls and sensors Power LED Status LED FIGURE 1 AX1500 Controller Front View At the back of the controller shown in the figure below are located all the terminals that must be connected to the batteries and the motors Note Both VMot terminals are conn
29. outputs that may be con nected to electrical accessories valves lights weapons The R C mode provides the simplest method for remotely controlling a robotic vehicle little else is required other than connecting the controller to the R C receiver using the provided cable and powering it On For better control and improved safety the AX1500 can be con figured to perform correction on the controls and will continuously monitor the transmis sion for errors FIGURE 61 R C radio control mode AX1500 Motor Controller User s Manual 101 R C Operation RoboteQ Selecting the R C Input Mode The R C Input Mode is the factory default setting If the controller has been previously set to a different Input Mode it will be necessary to reset it to the R C mode using the serial port and the PC utility See Using the Roborun Configuration Utility on page 161 and Accessing amp Changing Configuration Parameter in Flash on page 133 Connector I O Pin Assignment R C Mode FIGURE 62 Pin locations on the controller s 15 pin connector When used in R C mode the pins on the controller s DB15 connector are mapped as described in the table below TABLE 16 Connector pin out in R C mode Pin Input or Number Output Signal Description 1 and9 Output Output C 2A Accessory Output C 2 Output RS232 data RS232 Data Logging Output 3 Input Ch 1 R C radio
30. possible to use a lower current power supply Batteries mounted in this way should be connected for the first time only while fully charged and should not be allowed to discharge The power supply will be required to output unsafe amounts of current if connected directly to a discharged battery Consider using a decoupling diode on the power supply s output to prevent battery or regeneration current to flow back into the power supply Place a resistive load in parallel with the power supply with a circuit to enable that load during regeneration This solution is more complex but will provide a safe path for the braking energy into a load designed to dissipate it To prevent current from flowing from the power supply into the load during normal operation an active switch would enable the load when the voltage rises above the nominal output of the power supply AX1500 Motor Controller User s Manual 37 Connecting Power and Motors to the Controller lRoboteQ 38 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Basic Operation SECTION 5 General Operation This section discusses the controller s normal operation in all its supported operating modes Basic Operation The AX1500 s operation can be summarized as follows e Receive commands from a radio receiver joystick or a microcomputer e Activate the motors according to the received command e Perform continuous check of fault c
31. s main board harsh shock and vibration environments solder a metal wire inside the 0 1 hole found on the main board next to one of the two header and solder the other en inside the matching hole on the encoder module as shown on Figure 39 Connecting the Encoder Encoder Module setae wire Main Board FIGURE 39 Solder wire for robust assembly The Encoder module uses a widely available 8 pin RJ45 connector identical to those found on all Ethernet devices The connector provides 5V power to the encoders and has inputs for the two quadrature signals from each encoder Using multi level signaling it is also pos sible to share the quadrature inputs with limit switches The figure and table below describe the connector and its pin assignment 70 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lIRoboteQ Cable Length and Noise Considerations Hh 1 8 8 1 FIGURE 40 Encoder connector TABLE 12 Encoder Connector Pinout Cable Color Pin Name when using standard network cable 1 Encoder 2 Channel B Optional Limit Switch 4 Orange White 2 Encoder 2 Channel A Optional Limit Switch 3 Orange 3 Ground same as pin 7 Green White 4 5V Out same as pin 8 Blue 5 Encoder 1 Channel B Optional Limit Switch 2 Blue White 6 Encoder 1 Channel A Optional Limit Switch 1 Green 7 Ground same as pin 3 Brown White 8 5V Out same
32. see Command Control Curves on page 46 116 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Analog Deadband Adjustment Voltage at Input 5V 4V 3V 100K Pot 10K Pot 2V 1V OV Min Center Max Potentiometer Position FIGURE 77 Effect of the controller s internal resistors on various potentiometers Analog Deadband Adjustment The controller may be configured so that some amount of potentiometer or joystick travel off its center position is required before the motors activate The deadband parameter can be one of 8 values ranging from 0 to 7 which translate into a deadband of 0 to 16 Even though the deadband will cause some of the potentiometer movement around the center position to be ignored the controller will scale the remaining potentiometer move ment to command the motors from 0 to 100 Note that the scaling will also cause the motors to reach 100 at slightly less than 100 of the potentiometer s position This is to ensure that 100 motor speed is achieved in all circumstances Table 19 below shows the effect of the different deadband parameter val ues Changing the deadband parameter can be done using the controller s switches see Configuring the Controller using the Switches on page 171 or the Roborun utility on a PC see Loading Changing Controller Parameters on page 164 TABLE 19 Analog deadband parameter
33. seen by encoder using multi levels and limit switches Using this circuit when the switch is open a OV low level output from the encoder goes through a 1k and 4 7k voltage divider thus creating a voltage that will never be below 0 8V at the encoder module s input When the switch is activated the module s input is pulled to OV It is recommended that a voltmeter and or oscilloscope be used to verify that the right volt age levels are created as the encoder rotates and the switches activate You may also use the Encoder setup test function in the Roborun utility see Encoder Testing and Setting Using the PC Utility on page 79 If the wiring is correct the counters should increment decrement as the motor rotate The switch indicators should be always off unless the switches are actually activated 74 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 Wiring Limit Switches Without Encoders RoboteQ Wiring Limit Switches Without Encoders If no encoder is used the Encoder Module s inputs can be used to wire limit switches directly with solely a pull up resistor as shown in the diagram below WUOAL Y WUOAL Y WUOAL Y WUOAL Y Encoder Input Sw1 SW2 FIGURE 45 Signals seen by encoder using multi levels and limit switches Effect of Limit Switches Each pair of limit switches will stop the motion of a given motor in a given direction This will have the effect of stopp
34. than the user preset value The current limit may be set using the supplied PC utility Using the PC utility is it possible to set the limit with a 0 25A granularity from 3 25A to 30A During normal operation current limiting is further enhanced by the techniques described in the following sections Temperature Based Current Limitation The AX1500 features active current limitation that uses a combination of a user defined preset value discussed above which in turn may be reduced automatically based on mea sured operating temperature This capability ensures that the controller will be able to work safely with practically all motor types and will adjust itself automatically for the various load conditions When the measured temperature reaches 800C the controller s maximum current limit begins to drop to reach OA at 1000C Above 1000C the controller s power stage turns itself off completely TABLE 3 Effect of Heatsink temperature on Max Amps Limit Temperature Max Amps Below 80 oC 30A 80 oC 30A 85 oC 20A 90 oC 15A 95 oC 5A 100 oC 0 Above 100 oC Both Power Stages OFF 42 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Battery Current vs Motor Current The numbers in the table are the max Amps allowed by the controller at a given tempera ture point If the Amps limit is manually set to a lower value then the controller will limit the current
35. the motors to the power supply during regenera tion As discussed in Power Regeneration Considerations on page 35 if the supply is not able to absorb and dissipate regenerated current the voltage will increase until the over voltage protection circuit cuts off the motors While this process should not be harmful to the controller it may be to the power supply unless one or more of the protective steps below is taken 36 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Using the Controller with a Power Supply Use a power supply that will not suffer damage in case a voltage is applied at its output that is higher than the transformer s own output voltage This information is seldom published in commercial power supplies so it is not always possible to obtain positive reassurance that the supply will survive such a condition Avoid deceleration that is quicker than the natural deceleration due to the friction in the motor assembly motor gears load Any deceleration that would be quicker than natural friction means that braking energy will need to be taken out of the sys tem causing a reverse current flow and voltage rise See Programmable Accelera tion on page 45 Place a battery in parallel with the power supply output This will provide a reservoir into which regeneration current can flow It will also be very helpful for delivering high current surges during motor acceleration making it
36. the third channel is for activating the accessory outputs and is optional When operating the controller in Separate mode the wire labelled Ch1 controls Motor1 and the wire labelled Ch2 controls Motor2 When operating the controller in Mixed mode Ch1 is used to set the robot s speed and direction while Ch2 is used for steering See R C Operation on page 101 of the User s Manual for a more complete discussion on R C commands calibration and other options Channel 3 3 Channel 1 Command Pulses 4 Channel 2 Command Pulses 6 Radio battery Ground a Radio battery 8 Channel 3 Command Pulses Wire loop bringing power from controller to RC radio FIGURE 4 R C connector wiring for 3 channels and battery elimination BEC This wiring with the wire loop uncut assumes that the R C radio will be powered by the AX1500 controller Other wiring options are described in R C Operation on page 101 of the User s Manual Important Warning Do not connect a battery to the radio when the wire loop is uncut The RC battery voltage will flow directly into the controller and cause permanent damage if its volt age is higher than 5 5V Connecting the optional channel 3 will enable you to turn on and off the accessory output See Connecting Sensors and Actuators to Input Outputs on page 51 and Activating the Accessory Outputs on page 110 of the User s Manual AX1500 Motor Control
37. their wires isolated from the motor casing Some motors particularly automotive parts use only one wire with the other connected to the motor s frame AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Single Channel Operation If you are using this type of motor make sure that it is mounted on isolators and that its casing will not cause a short circuit with other motors and circuits which may also be inadvertently connected to the same metal chassis Single Channel Operation The AX1500 s two channel outputs can be paralleled as shown in the figure below so that they can drive a single load with twice the power To perform in this manner the control ler s Power Transistor that are switching in each channel must be perfectly synchronized Without this synchronization the current will flow from one channel to the other and cause the destruction of the controller The controller may be ordered with the SC Single Channel suffix This version incorpo rates a hardware setting inside the controller which ensures that both channels switch in a synchronized manner and respond to commands sent to channel 1 Warning Use this wiring only with SC versions Single Channel of the controller Pwr Ctrl 12V to 40V GND Controller FIGURE 11 Wiring for Single Channel Operation Converting the AX1500 to Single Channel The AX1500 can be easily modified into a Single Channel ver
38. then transferred in a single step using a command When reading a counter a read command is sent to the encoder module which then copies the counter value into the mailbox The mailbox system can be used in the same way for reading and writing the des tination register In practice reading a counter is done by a single command described in Read Encoder Counter on page 145 This command will perform the steps above and output the selected counter value Writing a user defined value into a counter or destination register requires that the value be loaded in the mailbox using the steps defined in Read Modify Encoder Module Registers and Parameters on page 148 and then that of one of the commands described in Set Reset Encoder Counters and Destination Registers on page 145 be issued Counter 1 and 2 Address 8C Most Significant Byte Counter 1 8D 8E 8F Least Significant Byte 90 Most Significant Byte Counter 2 91 92 93 Least Significant Byte These two 32 bit 4 bytes registers are the actual counters As discussed above they should not be accessed directly as their value may fluctuate between the four accesses needed to read or write a complete 32 bit counter Destination Register 1 and 2 Address Address 94 Most Significant Byte Destination 1 95 96 97 Least Significant Byte 98 Most Significant Byte Destination 2 99 AX1500 Motor Controller User s Manual 151
39. these signals become available for user application Below is a summary of the available signals and the modes in which they are used by the controller or available to the user TABLE 7 AX1500 IO signals and definitions Signal I O type Use Activated Out C 2A Digital Output User Activated using R C channel 3 R C mode or defined serial command RS232 mode Activated when any one motor is powered when enabled Inp F Digital Input User Active in RS232 mode only Read with serial com defined mand RS232 Activate When Input is configured to drive Output C Output C Turn FETs When Input is configured as dead man switch On Off input Inp E Digital Input Same as Input F Not available when encoder module present EStop Invert Digital Input Emer When Input is configured as Emergency Stop gency stop switch input Invert When Input is configured as Invert Controls Controls switch input User When input is configured as general purpose defined Read with serial command RS232 Analog In 1 Analog Input Tachome When Channel 1 is configured in Closed Loop ters input Speed Control with Analog feedback Position When Channel 1 is configured in Closed Loop sensing Position Control with RC or RS232 command and Analog feedback User Read value with serial command RS232 defined Analog In 2 Analog Input 2 Same as Analog 1 but for Channel 2 Analog In 3 Analog Input 3 Position When C
40. 0 Separate A B speed control open loop C Amp limit 5 26 25A A Acceleration 2 medium slow S Input switch function 3 no action U Joystick Deadband 2 16 d Exponentiation on channel 1 0 Linear no exponentiation E Exponentiation on channel 2 0 Linear no exponentiation F Left Right Adjust 7 no adjustment L Any one of the parameters listed in Table 1 and others not listed can easily be changed either using the PC with the Roboteq Configuration Utility See Using the Roborun Config uration Utility on page 161 20 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ Connecting the controller to your PC using Roborun Connecting the controller to your PC using Roborun Connecting the controller to your PC is not necessary for basic R C operation However it is a very simple procedure that is useful for the following purposes to Read and Set the programmable parameters with a userfriendly graphical inter face to obtain the controller s software revision and date to send precise commands to the motors to read and plot real time current consumption value Save captured parameters onto disk for later analysis to update the controller s software Ff RoboRun x Controller Info oboteQ i 4 Controller Communication OK Controller ID RoboteQ AX3500 z ali Software Rev 1 9b 05 27 07 Controller Configuration Utility ante Re 2 FETs por
41. 0 4 16 1 92 0 93 Internal Resistors and Converter 47kOhm C 10kOhm 47kOhm 10kOhm 10kOhm NTC Thermistor Ground 5 FIGURE 30 NTC Thermistor wiring diagram Thermistors are non linear devices Using the circuit described on Figure 30 the controller will read the following values represented in signed binary according to the temperature AX1500 Motor Controller User s Manual 61 Connecting Sensors and Actuators to Input Outputs lRoboteQ 100 50 50 Analog Input Reading 100 150 4 S E R e Temperature in Degrees C P tee FIGURE 31 Signed binary reading by controller vs NTC temperature To read the temperature use the p command to have the controller return the A D con verter s value The value is a signed 8 bit hexadecimal value Use the chart data to convert the raw reading into a temperature value Using the Analog Inputs to Monitor External Voltages The analog inputs may also be used to monitor the battery level or any other DC voltage In this mode the controller does not use the voltage information but merely makes it avail able to the host microcomputer via the RS232 port The recommended schematic is shown in Figure 32 To Battery 5V 14 Terminal F Internal Resistors Ana 1 11 and Convert
42. 0 incorporates voltage sensors that monitor the Main Battery voltage and the Internal 12V supply This information is used by the controller to protect it against overvolt age and undervoltage conditions see Overvoltage Protection on page 36 and Under voltage Protection on page 36 These voltages can also be read from the RS232 serial port using the e query The returned value are numbers ranging from O to 255 To convert these numbers into a Voltage figure the following formulas must be used Measured Main Battery Volts 55 Read Value 256 Measured Internal Volts 28 5 Read Value 256 Internal Heatsink Temperature Sensors The AX1500 includes temperature sensors near the transistor of each of the two output stages AX1500 Motor Controller User s Manual 63 Connecting Sensors and Actuators to Input Outputs RoboteQ These sensors are used to automatically reduce the maximum Amps that the controller can deliver as it overheats However the temperature can be read using the RS232 port using the m query or during data logging see Analog and R C Modes Data Logging String Format on page 156 The analog value that is reported will range from 0 warmest to 255 coldest Because of the non linear characteristics of NTC thermistors the conversion from measured value to temperature must be done using the correction curve below It should be noted that the temperature is measured inside the controlle
43. 00 followed by 101 Read counter 1 and copy its value into counter 2 Read Speed Description This query will cause the controller to return the speed computed by the Encoder module The values are signed Hexadecimal numbers ranging from 127 to 127 The 127 value rep resents the maximum RPM in the reverse direction 127 represents the maximum RPM in the forward direction The relation of this relative number and the actual absolute RPM value depends on the encoder s resolution and a user programmable Time Base See Using the Encoder to Measure Speed on page 76 for a detailed discussion Syntax z or Z Reply nn mm Where nn speed 1 value mm speed 2 value Notes The command returns a signed hexadecimal number where 0 to 127 is represented by 00 to 7F and 1 to 127 is represented by FF to 80 respectively The hexadecimal format is intended to be deciphered by a microcontroller When exercising the controller manually you may use the Decimal to Hexadecimal conversion table on page 157 146 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ RS232 Encoder Command Set Read Distance Description This query will cause the controller to return the distance between the current position and the value in the destination register The values are signed Hexadecimal numbers ranging from 127 to 127 The 127 value represents the relative distance according to the formu las described in Us
44. 1 AX1500 Connections 51 AX1500 s Inputs and Outputs 52 I O List and Pin Assignment 54 Connecting devices to Output C 55 Connecting Switches or Devices to Input E 56 Connecting Switches or Devices to Input F 56 Connecting Switches or Devices to EStop Invert Input 57 Analog Inputs 58 Connecting Position Potentiometers to Analog Inputs 58 Connecting Tachometer to Analog Inputs 59 Connecting External Thermistor to Analog Inputs 61 Using the Analog Inputs to Monitor External Voltages 62 Connecting User Devices to Analog Inputs 63 Internal Voltage Monitoring Sensors 63 Internal Heatsink Temperature Sensors 63 SECTION 7 Installing Connecting and Using the Encoder Module 67 Optical Incremental Encoders Overview 67 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ Recommended Encoder Types 68 Installing the Encoder Module 69 Connecting the Encoder 70 Cable Length and Noise Considerations 71 Motor Encoder Polarity Matching 72 Voltage Levels Thresholds and Limit Switches 72 Wiring Optional Limit Switches 73 Wiring Limit Switches Without Encoders 75 Effect of Limit Switches 75 Using the Encoder Module to Measure Distance 76 Using the Encoder to Measure Speed 76 Using the Encoder to Track Position 77 RS232 Communication with the Encoder Module 78 Encoder Testing and Setting Using the PC Utility 79 SECTION 8 Closed Loop Position Mode 81 Mode Description 81 Selecting the Position Mode 81 Position
45. 12V to 40V 12V to 40V Controller Motor Battery Backup Battery FIGURE 10 Powering the AX1500 with a Main and Backup Supply Important Warning Unless you can ensure a steady 12V to 40V voltage in all conditions it is recom mended that the battery used to power the controller s electronics be separate from the one used to power the motors This is because it is very likely that the motor bat teries will be subject to very large current loads which may cause the voltage to eventually dip below 12V as the batteries charge drops The separate backup power supply should be connected to the Power Control input Connecting the Motors Connecting the motors is simply done by connecting each motor terminal to the M1 M2 and M1 M2 terminal Which motor terminal goes to which of the or controller output is typically determined empirically After connecting the motors apply a minimal amount of power using the Roborun PC util ity with the controller configured in Open Loop speed mode Verify that the motor spins in the desired direction Immediately stop and swap the motor wires if not In Closed Loop Speed or Position mode beware that the motor polarity must match this of the feedback If it does not the motors will runaway with no possibility to stop other than switching Off the power The polarity of the Motor or off the feedback device may need to be changed Important Warning Make sure that your motors have
46. 1500 sup ports a programmable deadband feature A small deadband is set in the controller by default at the factory This deadband can be stretched reduced or eliminated using the Roborun utility The AX1500 has 8 preset deadband values coded 0 to 7 The value 0 dis ables the deadband Other values select a deadband according to the table below The deadband value applies equally to both joysticks 108 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Command Control Curves The deadband is measured as a percentage of total normal joystick travel For example a 16 deadband means that the first 16 of joystick motion in either direction will have no effect on the motors TABLE 17 Selectable deadband values Deadband Parameter Value Deadband as Percent of full Joystick Travel No deadband 8 16 default value 24 32 40 46 54 Qaj ja a alra a a a i NJol l a aA lwlrm salo Note that the deadband only affects the start position at which the joystick begins to take effect The motor will still reach 100 when the joystick is at its full position An exagger ated illustration of the effect of the deadband on the joystick action is shown in the Figure 71 below Deadband Min no action Min Reverse Forward Max Reverse Max Forward Centered Position FIGURE 71 Effect of deadband on joystick position vs motor speed C
47. 27 16 127 32 78 64 39 128 FIGURE 47 Large distance computation example Important Notice Encoders do not report an absolute position value but a count that is relative to the point where the motor shaft was at power up It is typically necessary to have the motors moved to a home position and reset the counters at that reference point RS232 Communication with the Encoder Module The contains its own Microcontroller and firmware in Flash When present it responds to a large set of dedicated commands and queries via the controller s serial port See RS232 Encoder Command Set on page 145 78 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Encoder Testing and Setting Using the PC Utility Encoder Testing and Setting Using the PC Utility Extensive diagnostic calibration setting and testing support is provided in the Roborun PC utility Basic instructions on how to install and run the PC utility can be found in Encoder Setting and Testing on page 168 AX1500 Motor Controller User s Manual 79 Installing Connecting and Using the Encoder Mod lRoboteQ 80 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Mode Description SECTION 8 Closed Loop Position Mode This section describes the AX1500 Position mode how to wire the motor and position sen sor assembly and how to tune and operate the controller
48. 3 Encoder ID v1 7 02 01 05 13 View Coni Pi ower Settings R C Ana Specific Close Loop Encoder RC Out Run Console Reset to defaults Input RS 232 F WatchDog Load from Controller Reset Controller for these changes to take effect Motor Control Mode fA and B Speed Separate gt V Closed Loop Save to Controller FeedbackA C Analog Encoder I Limit Switches Feedback B C Analog Encoder Load Profile from Disk Chanel 1 Chanel 2 Save Profile to Disk Input Adjustment Linear linear ss Change COM LAN Port EStop inv Input No Action M COM1 is selected Input E Mode NoAcion InputF Mode No Action Update Controller Software Out C ON when Motors Active FIGURE 88 Roborun screen layout The Roborun screen contains the four main set of commands and information frames described below 1 Program Revision Number This is the revision and date of the Roborun utility It is recommended that you always ver ify that you have the latest revision of the utility from Roboteq s web site at www roboteq com 2 Controller and Communication Link Information This frame will automatically be updated with an indication that a free communication port was found and opened by the utility If no free communication port is available on your computer it will be indicated in this win dow Try to select another port using the Change COM Port button or try to free the por
49. 55 Register Value The controller s default frequency provides the best efficiency and should be changed only if absolutely required and only if operating the controller in RS232 or Analog modes Changes to the PWM frequency will affect the RS232 watchdog timer and PID may need re tuning The controller automatically reverts to the default 16kHz PWM frequency after reset Controller Status Register Address 89 Access Read Only Effective Instantly The Controller Status Register can be polled at any time to see if there is a pending fault condition Any one bit set will cause the controller to turn off the Power Output stage Con ditions marked as Temporary mean that the controller will resume operation as soon as the fault condition disappears Permanent conditions will cause the controller to remain off until it is reset either by cycling power pressing the reset button or sending the rrrrrr command TABLE 25 Controller Status Register Definition Bit Fault Condition Effect 0 Overvoltage Temporary 1 Overtemperature Temporary 2 Undervoltage Temporary 3 Manually Forced MOSFETs Off Temporary 4 Unused AX1500 Motor Controller User s Manual 143 Serial RS 232 Controls and Operation lRoboteQ TABLE 25 Controller Status Register Definition Bit Fault Condition Effect 5 Confirmed Short Circuit Permanent 6 Confirmed Encoder Error Permanent 7 Emergency Stop P
50. 9 Accessory Output C same as pin 1 Pin 10 Analog Input 2 Pin 11 i Analog Input 1 Pin 12 Analog Input 3 Pin 13 i Ground Pin 14 SY Output Pin 15 EEEa Stop or Invert Switch input Analog Inputs 3 and 4 are present in 2007 models Not Connected in 2007 models FIGURE 89 Roborun screen layout Getting On Screen Help The Roborun buttons and fields are very intuitive and self explanatory Additional explana tions and help is provided by means of ToolTips for several of command Simply move the cursor to a button tab or other gadget on the screen and a message box will appear after a few seconds Loading Changing Controller Parameters The first set of tabs allows you to view and change the controller s parameters These tabs are grouped according to the general type of parameters Controls Power Setting and R C Settings 164 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lIRoboteQ Loading Changing Controller Parameters When starting Roborun this screen is filled with the default values If the controller is con nected to your PC Roborun will automatically detect it and ask you if you wish to read its settings The controller s setting in the PC at can be read any other time by pressing the Load from Controller button After changing a parameter you must save it to the controller manually by pressing the Save to Controller button Con
51. Address 167 4 182 110 Connections J FIGURE 98 Roboserver screenshot when idle Note that it is not possible to use this configuration to change the controller s parameters or update the controller s software AX1500 Motor Controller User s Manual 177 Using the Roborun Configuration Utility lRoboteQ Updating the Controller s Software The AX1500 s operating software can be easily upgraded after it has left the factory This feature makes it possible to add new features and enhance existing ones from time to time Important Warning Updating the controller will cause all its parameters to reset to their default condi tions You should re enter these parameters to the desired value prior to re installing and using the controller The upgrade procedure is quick easy and error proof 1 Connect the controller to the PC via the provided RS232 cable 2 Apply a 12V to 40V power supply to the controller s Ground and Power Control input Leave VMot disconnected 3 Launch the Roborun utility if it is not already running Then click on the Update Con troller Software button 4 Ifthe controller is On Roborun will find it and prompt the selection of the new soft ware file It may happen that the controller is not responding properly and you may be asked to reset it while connected 5 Press the Program button to start programming Do not interrupt or cut the power to the contro
52. Ana2 Feedback 1 O 12 Ana3 Feedback 2 8 Ana4 FIGURE 50 Pot wiring for Analog Command and Analog Feedback Analog inputs 3 and 4 have different characteristics than inputs 1 and 2 and so require a lower resistance potentiometer in order to guarantee accuracy Important Notice This wiring is also the one to use when the controller is in Analog mode but switched to RS232 after reset using the method discussed in Entering RS232 from R C or Analog mode on page 126 84 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Analog Feedback on Single Channel Controllers Analog Feedback on Single Channel Controllers On Single Channel controllers SC Version not to be confused with Dual Channel control lers of which only one channel is used for position control See Single Channel Opera tion on page 177 the controller accepts one command and uses one input for feedback Feedback Wiring in RC or RS232 Mode on Single Channel Controllers When the controller is configured for RS232 or RC command the wiring of the feedback must be done as shown in the figure below O 14 5V 2k 10k O 5 Ground O 11 Anal Feedback O 10 Ana2 O 12 Ana3 O 8 Ana4 FIGURE 51 Pot wiring on Single Channel controllers SCversion and Analog Command Feedback Wiring in Analog Mode on Single Channel Controllers When the controller is configured in Analog mode the analog in
53. Battery Voltages 131 Query Digital Inputs 132 Reset Controller 132 Accessing amp Changing Configuration Parameter in Flash 133 Apply Parameter Changes 133 Flash Configuration Parameters List 134 Input Control Mode 135 Motor Control Mode 135 Amps Limit 136 Acceleration 137 Input Switches Function 137 RC Joystick or Analog Deadband 138 Exponentiation on Channel 1 and Channel 2 138 Left Right Adjust 139 Default Encoder Time Base 1 and2 139 Default Encoder Distance Divider 140 Default PID Gains 140 Joystick Min Max and Center Values 140 Reading amp Changing Operating Parameters at Runtime 141 Operating Modes Registers 142 Read Change PID Values 142 PWM Frequency Register 143 Controller Status Register 143 AX1500 Motor Controller User s Manual RoboteQ Controller Identification Register 144 Current Amps Limit Registers 144 RS232 Encoder Command Set 145 Read Encoder Counter 145 Set Reset Encoder Counters and Destination Registers 145 Read Speed 146 Read Distance 147 Read Speed Distance 147 Read Encoder Limit Switch Status 147 Read Modify Encoder Module Registers and Parameters 148 Register Description 150 Encoder Hardware ID code 150 Switch Status 150 Speed or Distance 1 or 2 150 Counter Read Write Mailbox 151 Counter 1 and2 151 Destination Register 1 and2 151 Distance 1 and2 152 Speed 1 and2 152 Time Base 1 and2 152 Encoder Threshold 152 Distance Divider 152 Counter Read Data Format 153 Encoder
54. C or microcomputer to match those of the controller Establishing Manual Communication with a PC The controller can easily be connected to a PC in order to manually exercise its capabilities Simply connect the supplied cable to the AX1500 on one end DB 15 connector and to a free COM port on the other end DB 9 connector Once connected you will need a Terminal Emulation program to display the data received from the controller on the PC s screen and to send characters typed on the keyboard to the controller All Windows PC s come with the Hyperterm terminal emulation software Locate the Hyperterm launch icon in the Start button Programs gt Accessories gt Commu nication folder You will need to configure Hyperterm to use the COM port to which you have connected the controller typically COM1 and to configure the communication settings as described in the section above To save time and avoid errors a hyperterm configuration file is automatically installed in your PC s Start button menu when the Roboteq s Roborun utility is installed See Down loading and Installing the Utility on page 161 The configuration file is set to use the 124 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Establishing Manual Communication with a PC COM1port You can easily change this setting to a different port from the program s menus Note that starting with version 1 9 the Roborun PC utility also
55. Channel 1 pulses 4 Input Ch 2 R C radio Channel 2 pulses 5 and 13 Power Out Ground Controller ground 6 Unused Unused Unused 7 Unused Unused Unused 8 Digital In R C Ch 3 Ana In 4 R C radio Channel 3 pulses Not available when encoder module present 10 Analog in Ana in 2 Channel 2 speed or position feedback input 11 Analog in Ana in 1 Channel 1 speed or position feedback input 12 Analog in Ana in 3 Unused 102 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ R C Input Circuit Description TABLE 16 Connector pin out in R C mode Pin Input or Number Output Signal Description 14 Power Out 5V 5V Power Output 100mA max 15 Input Input EStop Inv Emergency Stop or Invert Switch input R C Input Circuit Description The AX1500 R C inputs are directly connected to the MCU logic Figure 63 shows an elec trical representation of the R C input circuit 5V Output z Controller Power R C Channel 1 R C Channel 2 R C Channel 3 Controller Ground FIGURE 63 AX1500 R C Input equivalent circuit Supplied Cable Description The AX1500 is delivered with a custom cable with the following wiring diagram AX1500 Motor Controller User s Manual 103 R C Operation IRoboteQ FIGURE 64 RC Cable wiring diagram FIGURE 65 RC connection cable Powering the Radio from the controller The 5V power and ground sig
56. EEREEE Temporary Fault EERE Permanent Error FIGURE 60 Status LED Flashing pattern during faults or other exceptions e Over temperature e Over Voltage e Under Voltage e Dead man switch activation See Using the Inputs to turn Off On the Power MOSFET transistors on page 50 The controller will resume the normal flashing pattern when the fault condition disappears A rapid continuously flashing pattern indicates that the controller s output is Off and will remain off until reset or power is cycled Activating the emergency stop will cause the con troller to stop in this manner A permanent error will also be triggered if the encoder mod ule is mounted and an encoder error is detected Note that while the controller is Off it will continue to respond to commands if in the RS232 mode and can thus be reset by sending the rrrrrr command 100 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRo b oteQ Mode Description SECTION 11 R C Operation This section describes the controller s wiring and functions specific to the R C radio control mode Mode Description The AX1500 can be directly connected to an R C receiver In this mode the speed or posi tion information is contained in pulses whose width varies proportionally with the joysticks positions The AX1500 mode is compatible with all popular brands of R C transmitters A third R C channel can be used to control the On Off state of two
57. Encoder to Track Position The encoder module can be used to report the distance between the actual motor position and a desired destination The resulting measured distance can then be used by the con troller in the position mode to move the motor in the right direction until the destination is reached This movement is controlled by the PID position algorithm inside the controller and is therefore best suited at tracking position Since the controller uses a signed 8 bit value 127 to 127 for the distance measurement in the Position Mode a special algorithm is used to convert the real distance which can be much higher than 127 to 127 as both the counter and destination registers are 32 bit wide AX1500 Motor Controller User s Manual 77 Installing Connecting and Using the Encoder Mod RoboteQ The actual formula is as follows Distance Destination Counter value Divider Where divider is a configurable parameter of value 1 2 4 8 16 32 64 or 127 If computed distance is less than 127 then reported distance is 127 If computed distance is larger than 127 then reported distance is 127 y Destination 50 050 Counter 50 000 distance at divider 50 1 25 2 12 4 6 8 3 16 1 32 0 64 0 128 FIGURE 46 Small distance computation example Destination 50 000 Counter 45 000 H distance at divider 127 1 127 2 127 4 127 8 1
58. F Output C OFF Output C ON FIGURE 73 Using Channel 3 to activate accessory outputs While in R C Mode the AX1500 will continuously send a string of characters on the RS232 output line This string will contain 12 two digit hexadecimal numbers representing the fol lowing operating parameters e Captured R C Command 1 and 2 e Power Applied to Controller s output stage e Values applied to Analog inputs 1 and 2 e Amps on channel 1 and 2 e Internal Heat Sink temperatures 1 and 2 e Main Battery voltage e Internal 12V voltage e Encoder Speed or Position feedback if encoder module is present The entire string is repeated every 200 milliseconds with the latest internal parameter val ues This information can be logged using the Roborun Utility see Viewing and Logging Data in Analog and R C Modes on page 176 It may also be stored in a PDA that can be placed in the mobile robot The string and data format is described in Analog and R C Modes Data Logging String For mat on page 156 The serial port s output can be safely ignored if it is not required in the application AX1500 Motor Controller User s Manual 111 R C Operation IRoboteQ To read the output string while operating the controller with the R C radio you must mod ify the R C cable to add an RS232 output wire and connector that will be connected to the PC s communication port Figure 74 and below shows the wiring diagram of the modified
59. Joystick calibration is also useful for modifying the active joystick travel area For example the figure below shows a transmitter whose joystick s center position has been moved back so that the operator has a finer control of the speed in the forward direction than in the reverse position The joystick timing values can be entered directly in the controllers flash memory using your PC running the Roborun configuration utility This method is described in Loading Changing Controller Parameters on page 164 New Desired Center Position Min Min Forward Reverse Max Reverse Max Forward FIGURE 72 Calibration example where more travel is dedicated to forward motion Activating the Accessory Outputs The AX1500 has a general purpose output that may be turned on and off using a third R C channel on the radio 110 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Data Logging in R C Mode Output C is a buffered output capable of driving a 2A device at up to 24V Details on how to wire this output to user accessories can be found at Connecting Sensors and Actuators to Input Outputs on page 51 The output is activated by pushing the joystick to the maximum position The output turns back off when the joystick is returned to the center position Note Channel 3 is not available on the controllers equipped with encoder inputs Data Logging in R C Mode Output C OF
60. Leg V 1 9b 06 01 07 Dual Channel Encoder ID v1 7 02 01 05 13 View Connector Pinout Controls Power Settings R C Ana Specific Close Loop Encoder RC Out Run Console I Log _Clear Log p Motor 1 K lo Bat Amps Run Empty Save Log o _Ch Peak J 0 00 22 Res Timer Jo Mot Amps gt Command 1 i 73 Power Step Ao Anat mm F 105 Ana3 P Plot 0 Bm Ene m Command 2 i 25 FET Temp Stop E Motor 2 K Io Bat Amps s fo _ClrPeak Input Outputs r Voltage 0 Mot Amps OB Input E E fis BatVolt fv 32 Power BB input F a E EStop nv C fig IntVol Ch Ana2 I Oc po Enable Config Ffo Enc Comm Error C 25 FET Temp Tx fa Rx p00FFIADD IBO0 FIGURE 6 Roborun Utility screen layout To connect the controller to your PC use the provided cable Connect the 15 pin connector to the controller Connect the 9 pin connector to your PC s available port typically COM1 use a USB to serial adapter if needed Apply power to the controller to turn it on Load your CD or download the latest revision of Roborun software from www Roboteg com install it on your PC and launch the program The software will auto matically establish communication with the controller retrieve the software revision num ber and present a series of buttons and tabs to enable its various possibilities AX1500 Motor Controller User s Manual AX1500 Qui
61. PC or Microcontroller every valid character it has received If no echo is received one of the following is occur ring e the controller is not in the RS232 mode e the controller is Off e the controller may be defective Command Acknowledgement The AX1500 will acknowledge commands in one of two ways For commands that cause a reply such as a speed or amps queries the reply to the query must be considered as the command acknowledgement For commands where no reply is expected such as speed setting the controller will issue a plus character after every command as an acknowledgment Command Error If a command or query has been received with errors or is wrong the control will issue a minus character to indicate the error If the controller issues the character it should be assumed that the command was lost and that it should be repeated Watchdog time out If the RS232 watchdog is enabled the controller will stop the motors and issue a W character if it has not received a valid character from the PC or microcontroller within the past 1 seconds AX1500 Motor Controller User s Manual 127 Serial RS 232 Controls and Operation IRoboteQ RS 232 Watchdog For applications demanding the highest operating safety the controller may be configured to automatically stop the motors but otherwise remain fully active if it fails to receive a character on its RS232 port for more than 1 second
62. S 232 Controls and Operation RoboteQ roboteq com1 HyperTerminal ioj xj File Edit View Call Transfer Help RoboteQ v1 7 01 02 05 Power up prompt from main MCU RoboEnc v1 7 01 02 05 Hardware Code of main board 8 Power up prompt from encoder MCU Hardware Code of Encoder Module OK Connected 0 00 12 autodetect o6007 E 1 SCROLL CAPS NUM Capture Printecho FIGURE 83 Hyperterm session showing power up messages from both MCUs After this information is sent the Encoder s MCU will listen for approximately 100ms and will enter the In System Programming mode ISP if the letter Z is sent to it While in the ISP mode new software can be loaded into the Encoder s MCU via the controller s main serial port Details on software updating are given in section Updating the Controller s Software on page 178 Entering RS232 from R C or Analog mode If the controller is configured in R C or Analog mode it will not be able to accept and recog nize RS232 commands immediately However the controller will be listening to the serial port and will enter the serial mode after it has received 10 continuous Enter Carriage Return characters At that point the controller will output an OK message indicating that it has entered the RS232 mode and that it is now ready to accept commands Note that for improved safety the RS232 watchdog is automatically enabled when enter
63. S232 mode Pin Input or Number Output Signal Description 1 and9 Output Output C 2A Accessory Output C 2 Output Data Out RS232 Data from Controller to PC 3 Input Data In RS232 Data In from PC 4 Input Input F Digital Input F readable RS232 mode Dead man switch activation 5 and 13 Power Out Ground Controller ground 6 Unused Unused Unused 7 Unused Unused Unused 8 Digital In and Input E Anain4 Accessory input E Analog In Dead man Switch Input Activate Output C Analog Input 4 10 Analog in Ana in 2 Channel 2 speed or position feedback input 11 Analog in Ana in 1 Channel 1 speed or position feedback input 12 Analog in Ana in 3 Analog input 3 14 Power Out 5V 5V Power Output 100mA max 15 Input Input EStop Inv Emergency Stop or Invert Switch input 122 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Cable configuration Cable configuration The RS232 connection requires the special cabling as described in the figure below The 9 pin female connector plugs into the PC or other microcontroller The 15 pin male connec tor plugs into the AX1500 It is critical that you do not confuse the connector s pin numbering The pin numbers on the drawing are based on viewing the connectors from the front facing the sockets or pins Most connectors have pin numbers molded on the plastic DB9 Female DB15 Male To PC To Controller IO O1
64. Sensor Selection 82 Sensor Mounting 82 Feedback Potentiometer wiring 83 Feedback Potentiometer wiring in RC or RS232 Mode 83 Feedback Potentiometer wiring in Analog Mode 84 Analog Feedback on Single Channel Controllers 85 Feedback Wiring in RC or RS232 Mode on Single Channel Controllers 85 Feedback Wiring in Analog Mode on Single Channel Controllers 85 Using Optical Encoders in Position Mode 86 Sensor and Motor Polarity 86 Encoder Error Detection and Protection 87 Adding Safety Limit Switches 87 Using Current Limiting as Protection 89 Control Loop Description 89 PID tuning in Position Mode 90 SECTION 9 Closed Loop Speed Mode 93 Mode Description 93 Selecting the Speed Mode 93 Tachometer or Encoder Mounting 94 Tachometer wiring 94 Speed Sensor and Motor Polarity 95 AX1500 Motor Controller User s Manual RoboteQ Adjust Offset and Max Speed 96 Control Loop Description 96 PID tuning in Speed Mode 97 SECTION 10 Normal and Fault Condition LED Messages 99 Power On LED 99 Diagnostic LED 99 Normal Operation Flashing Pattern 99 Output Off Fault Condition 100 SECTION 11 R C Operation 101 Mode Description 101 Selecting the R C Input Mode 102 Connector I O Pin Assignment R C Mode 102 R C Input Circuit Description 103 Supplied Cable Description 103 Powering the Radio from the controller 104 Connecting to a Separately Powered Radio 106 Operating the Controller in R C mode 106 Reception Watchdog 107 R C Transmi
65. Signals seen by encoder using direct connection and no limit switches In Figure 42 the encoder and switches are wired to the encoder module using a set of resistors designed to create a multi level signal combining both pieces of information Details on the necessary wiring is provided in the next section Since the encoder output signal is shifted up by a few volts it always stays above the Limit Switch comparator s threshold and no Switch Detection condition is generated However since the limit switches connect to ground when On the level will dip below the 0 5V and generate a Switch Detection condition 2 5V Signal on Channel A or B 0 5V Quadrature Signal Switch Detect Signal FIGURE 43 Signals seen by encoder using multi levels and limit switches Important Warning When a limit switch is activated the encoder signal that is shared with the switch is no longer visible by the encoder module and pulse counting and speed measure ment stops Wiring Optional Limit Switches If limit switches are needed by the application additional circuitry is required in order to create a multi level signal that shares the encoder and the switch information The figure below shows the electrical diagram of the required wiring AX1500 Motor Controller User s Manual 73 Installing Connecting and Using the Encoder Mod RoboteQ 5V Encoder Module GND FIGURE 44 Signals
66. Software e 5 Megabytes of free disk space If there is no free serial port available the Configuration Utility can still run but it will not be able to communicate with the controller If the PC is not equipped with an RS232 serial port one may be added using an USB to RS232 converter Downloading and Installing the Utility The Configuration Utility is included on the CD that is delivered with the controller or may be obtained from the download page on Roboteq s web site at www roboteg com It is recommended that you use the downloaded version to be sure that you have the latest update e download and run the file robosetup exe e follow the instructions displayed on the screen AX1500 Motor Controller User s Manual 161 Using the Roborun Configuration Utility lRoboteQ e after the installation is complete run the program from your Start Menu gt Programs gt Roboteq The controller does not need to be connected to the PC to start the Utility Connecting the Controller to the PC The controller must be connected to the PC to use the Utility to perform any of the follow ing functions e to read the current parameters stored in the controller and display them on the computer e to store new parameters in the controller e to exercise the motors using your PC e to update the controller s software e calibrate the Amps sensor If the controller is not connected the Configuration Utility can run and be used to a
67. V using a very low current switch for example Using the Inputs to turn Off On the Power MOSFET transistors When this setting is selected the controller s Power MOSFET transistors will be active and the controller will be operating normally only when the input is pulled to ground When the input is pulled high all the power MOSFETs are turned Off so that the motors are effectively disconnected from the controller This function is typically used to create a dead man switch when the controller is driven using an analog joystick The motors will be active only while the switch is depressed If the switch is left off for any reason the motors will be disconnected and allowed to free wheel rather than coming to an abrupt stop AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ AX1500 Connections SECTION 6 Connecting Sensors and Actuators to Input Outputs This section describes the various inputs and outputs and provides guidance on how to connect sensors actuators or other accessories to them AX1500 Connections The AX1500 uses a set of power wires located on the back of the unit and a DB15 con nector for all necessary connections The diagram on the figure below shows a typical wir ing diagram of a mobile robot using the AX1500 controller The wires are used for connection to the batteries and motors and will typically carry large current loads Details on the controller s powe
68. X1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRo b oteQ Feedback Potentiometer wiring The mechanical coupling between the motor and the sensor must be as tight as possible If the gear box is loose the positioning will not be accurate and will be unstable potentially causing the motor to oscillate Some sensor such as potentiometers have a limited rotation range of typically 270 degrees 3 4 of a turn which will in turn limit the mechanical motion of the motor potenti ometer assembly Consider using a multi turn potentiometer as long as it is mounted in a manner that will allow it to turn throughout much of its range when the mechanical assembly travels from the minimum to maximum position Important Notice Potentiometers are mechanical devices subject to wear Use better quality potenti ometers and make sure that they are protected from the elements Consider using a solid state hall position sensor in the most critical applications Optical encoders may also be used when operated as discussed in Using the Encoder to Measure Speed on page 76 Feedback Potentiometer wiring When using a potentiometer it must be wired so that it creates a voltage that is propor tional to its angular position OV at one extreme 5V at the other A 10K potentiometer value is recommended for this use Analog Feedback is normally connected to the Analog Inputs 1 and 2 except when the controller is configured i
69. age or most other types of analog sensors These inputs can be read at any time using the p query for Analog inputs 1 and 2 and the r query for Inputs 3 and 4 The fol lowing section show the various uses for these inputs Connecting Position Potentiometers to Analog Inputs When configured in the Position mode the controller s analog inputs are used to obtain position information from a potentiometer coupled to the motor axle This feature is useful in order to create very powerful servos as proposed in the figure below Position Feedback Potentiometer FIGURE 27 Motor and potentiometer assembly for position servo operation 58 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 Connecting Tachometer to Analog Inputs RoboteQ Connecting the potentiometer to the controller is as simple as shown in the diagram on Figure 28 5V 14 Internal Resistors and Converter 47kOhm A D 10kOhm 47kOhm 10kOhm Ground 5 FIGURE 28 Potentiometer wiring in Position mode The potentiometer must be attached to the motor frame so that its body does not move in relationship with the motor The potentiometer axle must be firmly connected to the gear box output shaft The gearbox must be as tight as possible so that rotation of the motor translates into direct changes to the potentiometers without slack at the gearbox s out put TABLE 9 Analog Posi
70. alog Deadband value In the R C mode this page is used to view and change parame ters used in the R C mode of operation None of these parameters has any effect when running the controller in RS232 mode If the controller is configured in RS232 mode some of these menus will turn gray but will remain active 1 Deadband This slider will let you set the amount of joystick motion off its center position before the motors start moving The slider will work identically in the R C or analog mode however the value will be different See Joystick Deadband Programming on page 108 and Analog Deadband Adjustment on page 117 2 Joystick Timing These fields are enabled only if the R C mode is selected These number areas will let you read and modify the R C pulse timing information used by the controller New values can be entered manually to create different capture characteristics They are also useful for viewing the stored values after an automatic joystick calibration sequence See Joystick Calibration on page 110 and Activating the Accessory Outputs on page 110 AX1500 Motor Controller User s Manual 167 Using the Roborun Configuration Utility RoboteQ Closed Loop Parameters Controls Power Settings R C Ana Specific i Encoder RC Out Run Console Min Max Proportional Gain Integral Gain 11 Differential Gain FIGURE 93 Closed Loop parameter setting screen
71. and Channel 2 forward command to value nn bnn Command Channel 2 reverse command to value nn IC Command Turn Accessory Output C n Ic Command Turn Accessory Output C Off a or A Query Read Battery Amps vor V Query Read Power Level applied to motors 2p or P Query Read Analog Inputs 1 and 2 ror R Query Read Analog Inputs 3 and 4 128 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Controller Commands and Queries TABLE 21 Controller s basic Commands and Queries Command Type Description 2m or M Query Read Heatsink Temperature e or E Query Read Battery and Internal Voltage i or Query Read Digital Inputs k or K Query Quick read of Encoder Speed or Position if present Set Motor Command Value Description Send a speed of position value from 0 to 127 in the forward or reverse direction for a given channel In mixed mode channel 1 value sets the common forward and reverse value for both motors while channel 2 sets the difference between motor 1 and motor 2 as required for steering In all other modes channel 1 commands motor 1 and channel 2 commands motor 2 Syntax Minn Where M A channel 1 forward direction a channel 1 reverse direction B channel 2 forward direction b channel 2 reverse direction Where nn Speed or position value in 2 Hexadecimal digits from 00 to 7F Examples 1A00 channel 1 to 0 IB7F channel 2 100 fo
72. ased Automatic Current Limitation e 30A up to 30 seconds per channel e 25A up to 1 minute AX1500 Motor Controller User s Manual 25 AX1500 Motor Controller Overview lRoboteQ e 20A extended e High current operation may be extended with forced cooling 125A peak Amps per channel 16kHz Pulse Width Modulation PWM output Auxiliary output for brake clutch or armature excitation Heat sink on PCB Advanced Safety Features Safe power on mode Optical isolation on R C control inputs Automatic Power stage off in case of electrically or software induced program fail ure Overvoltage and Undervoltage protection Regeneration current limiting Watchdog for automatic motor shutdown in case of command loss R C and RS232 modes Diagnostic LED Programmable motor acceleration Built in controller overheat sensor Emergency Stop input signal and button Data Logging Capabilities 13 internal parameters including battery voltage captured R C command tempera ture and Amps accessible via RS232 port Data may be logged in a PC PDA or microcomputer Compact Open Frame PCB Design Surface mount PCB design Efficient heat sinking Operates without a fan in most applications 4 20 106 7mm long x 4 20 106 7mm wide 200 to 850 C heatsink operating environment 4 00z 120g 26 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Power Connections SECTION 4 Connecting Power a
73. at InputE is shared with the Analog Input 4 If an analog sensor is connected the controller will return a Digital value of O if the voltage is lower than 0 5V and a value of 1 if higher Connecting Switches or Devices to Input F Input F is a general purpose digital input This input is only active when in the RS232 or Analog modes In R C mode this line is used as the radio channel 2 input When left open Input F is in an undefined stage As shown in the figure below a pull down or pull up resistor must be inserted when used with a single pole switch The resistor may be omitted when used with a dual pole switch AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Connecting Switches or Devices to EStop Invert Input 5V Out 14 5V Out 14 wes 2 0 5V In 7 Internal 5VIn 7 Internal Buffer Buffer Input F 4 10kOhm Input F 4 10kOhm 10kOhm GND Out 5 GND Out 5 FIGURE 25 Switch wiring to Input F The status of Input F can be read in the RS232 mode with the i command string The con troller will respond with three sets of 2 digit numbers The status of Input F is contained in the second set of numbers and may be 00 to indicate an Off state or 01 to indicate an On state Connecting Switches or Devices to EStop Invert Input This input is used to connect various switches or devices depending on the selected con troller configuration The factory default for thi
74. at takes experimenta tion AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ PID tuning in Position Mode The Roborun PC utility makes this experimentation easy by providing one screen for chang ing the Proportional Integral and Differential gains and another screen for running and monitoring the motors When tuning the motor first start with the Integral Gain at zero increasing the Proportional Gain until the motor overshoots and oscillates Then add Differential gain until there is no more overshoot If the overshoot persists reduce the Proportional Gain Add a minimal amount of Integral Gain Further fine tune the PID by varying the gains from these posi tions To set the Proportional Gain which is the most important parameter use the Roborun util ity to observe the three following values e Command Value e Actual Position e Applied Power With the Integral Gain set to 0 the Applied Power should be Applied Power Command Value Actual Position Proportional Gain Experiment first with the motor electrically or mechanically disconnected and verify that the controller is measuring the correct position and is applying the expected amount of power to the motor depending on the command given Verify that when the Command Value equals the Actual Position the Applied Power equals to zero Note that the Applied Power value is shown without the sign in the PC utility In the case where the
75. ay be left floating when ever possible pull it to an unfused12V or higher voltage to keep the controller logic solidly On In applications where the motors could be made to run through external force electric vehicle going downhill for example and generate 40V or more a diode should be placed across the fuse amp emergency switch to provide a path under all circumstances for the regeneration current See Power Regeneration Considerations on page 35 Important Warning Do not rely on cutting power to the controller for it to turn off if the Power Control is left floating If motors are spinning because the robot is pushed are pushed or because of inertia they will act as generators and will turn the controller On possi bly in an unsafe state ALWAYS ground the Power Control wire to turn the controller Off and keep it Off Powering the Controller Using a Main and Backup Battery In typical applications the main motor batteries will get eventually weaker and the voltage will drop below the level needed for the internal microcomputer to properly operate For all professional applications it is therefore recommended to add a separate 12V to 40V power supply to ensure proper powering of the controller under any conditions This dual battery configuration is highly recommended in 12V systems AX1500 Motor Controller User s Manual Connecting Power and Motors to the Controller RoboteQ Motor2 Power switch
76. ay use the Decimal to Hexadecimal conversion table on page 156 Query Battery Voltages Description This query will cause the controller to return values based on two internally measured volt AX1500 Motor Controller User s Manual 131 Serial RS 232 Controls and Operation lRoboteQ ages the first is the Main Battery voltage present at the thick red and black wires The sec ond is the internal 12V supply needed for the controller s microcomputer and MOSFET drivers The values are unsigned Hexadecimal numbers ranging from 0 to 255 To convert these numbers into a voltage figure use the formulas described in Internal Voltage Moni toring Sensors on page 63 Syntax e or E Reply nn mm Where nn main battery voltage value mm internal 12V voltage value Notes The hexadecimal format is intended to be deciphered by a microcontroller When exercis ing the controller manually refer to the Decimal to Hexadecimal conversion table on page 157 Query Digital Inputs Description This query will cause the controller to return the state of the controller s two accessory inputs inputs E and F and the state of the Emergency Stop Inverted input See Connect ing Sensors and Actuators to Input Outputs on page 51 for information on how to wire and use these signals The returned values are three sets of two digits with the values 00 to indicate a O or Off state or 01 to indicate a 1 or On state Syntax i
77. back in the power supply during regeneration potentially damaging it and or the controller Regeneration can also cause potential problems if the battery is disconnected while the motors are still spinning In such a case and depending on the command level applied at that time the regenerated current will attempt to flow back to the battery Since none is present the voltage will rise to potentially unsafe levels The AX1500 includes an overvolt age protection circuit to prevent damage to the output transistors see Overvoltage Pro tection on page 36 However if there is a possiblity that the motor could be made to spin and generate a voltage higher than 40V a path to the battery must be provided even after a fuse is blown This can be accomplished by inserting a diode across the fuse as shown in Figure 9 on page 30 AX1500 Motor Controller User s Manual 35 Connecting Power and Motors to the Controller RoboteQ Please download the Application Note Understanding Regeneration from the www roboteq com for an in depth discussion of this complex but important topic Important Warning Use the AX1500 only with a rechargeable battery as supply to the Motor Power wires VMot terminals If a transformer or power supply is used damage to the con troller and or power supply may occur during regeneration See Using the Control ler with a Power Supply on page 36 for details Important Warning Avoid swi
78. battery against after the controller has failed Important Warning Fuses are typically slow to blow and will thus allow temporary excess current to flow through them for a time the higher the excess current the faster the fuse will blow This characteristic is desirable in most cases as it will allow motors to draw surges during acceleration and braking However it also means that the fuse may not be able to protect the controller Wire Length Limits The AX1500 regulates the output power by switching the power to the motors On and Off at high frequencies At such frequencies the wires inductance produces undesirable effects such as parasitic RF emissions ringing and overvoltage peaks The controller has built in capacitors and voltage limiters that will reduce these effects However should the wire inductance be increased for example by extending the wire length these effects will AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Electrical Noise Reduction Techniques be amplified beyond the controller s capability to correct them This is particularly the case for the main battery power wires Important Warning Avoid using long cable lengths beyond 2 feet from the main power battery to the controller as the added inductance may cause damage to the controller when oper ating at high currents Try extending the motor wires instead since the added induc tance is less harmful o
79. ching from RS232 to RC Mode on page 155 Reading and writing parameters is done using the fol lowing commands Read parameter Syntax Amm Reply DD Where mm parameter number DD current parameter value Example A400 Read value parameter 0 01 Controller replies value is 01 Modify parameter Syntax mm nn Reply if command was executed successfully if error Where mm parameter number nn new parameter value Examples 02 03 Store 03 into parameter 2 Notes All parameters and values are expressed with 2 hexadecimal digits No changes will be made and an error will be reported character when attempting to read or write a parameter that does not exist or when attempting to store a parameter with an invalid value Apply Parameter Changes Description Many parameters will take effect only after the controller is reset This command can be used instead of resetting the controller to cause these parameters to take effect after only a 100ms delay AX1500 Motor Controller User s Manual 133 Serial RS 232 Controls and Operation IRoboteQ Syntax AFF Reply Success changed parameters are now active if error Table 22 below lists the complete set of configuration parameters that may be accessed and changed using RS232 commands Flash Configuration Parameters List TABLE 22 Configuration parameters in Flash
80. ck Start lRoboteQ The intuitive Graphical User Interface will let you view and change any of the controller s parameters The Run tab will present a number of buttons dials and charts that are used for operating and monitoring the motors Obtaining the Controller s Software Revision Number One of the unique features of the AX1500 is the ability to easily update the controller s operating software with new revisions downloaded from Roboteq s web site at www roboteq com This is useful for adding features and or improving existing ones Each software version is identified with a unique number Obtaining this number can be done using the PC connection discussed previously Now that you know your controller s software version number you will be able to see if a new version is available for download and installation from Roboteq s web site and which features have been added or improved Installing new software is a simple and secure procedure fully described in Updating the Controller s Software on page 178 of the User s Manual Exploring further By following this quick start section you should have managed to get your controller to operate in its basic modes within minutes of unpacking Each of the features mentioned thus far has numerous options which are discussed further in the complete User s Manual including e Self test mode e Emergency stop condition e Using Inputs Outputs e Current limiting
81. connectors The Front View Rear View eee ee 4 OS Female to PC with RxData Only 00000000 1 Cut ME ms jn 3 i Female to PC with Rx andTx Data 1 0000000 2 Oo O Female to Application 1 KO 200 000 Q Male to controller 00000000 TTT FIGURE 86 ASCII string sent by the controller while in R C or Analog mode male connector plugs into the controller The application cable that would normally plug into the controller may now be plugged into one of the adapter s female connector 2 The PC can be plugged into connector 3 or 4 Connector 3 has the Rx and Tx data lines needed for full duplex serial communication thus allowing the PC to send commands to the con troller Connector 4 has the Rx line cut so that only a data flows only from the controller to the PC This configuration is for capturing the data logging strings sent in the RC or Analog modes Decimal to Hexadecimal Conversion Table The AX1500 uses hexadecimal notation for accepting and responding to numerical com mands Hexadecimal is related to the binary system that is used at the very heart of micro computers Functions for converting from decimal to hexadecimal are readily available in high level languages such as C If the user intends to enter commands manually using the terminal emulation program the conversion table in Table 30 can be used to do the translation Note that the table only
82. controller considers 2 5V to be the zero position Motor Off OV is the maximum reverse command and 5V is the maximum forward command The inputs equivalent circuit is show in Figure 75 below 5V 14 Internal Resistors and Converter Analog Int pin 11 In2 pin 10 47kOhm OV Min 2 5V Off 5V Max 10kOhm 47kOhm Ground FIGURE 75 Analog input circuit Notice the two 47K resistors which are designed to automatically bring the input to a mid point Off position in case the input is not connected The applied voltage must have suffi cient current low impedance so that it is not affected by these resistors Connecting a Potentiometer Figure 76 shows how to wire a potentiometer to the AX1500 By connecting one end to ground and the other to 5V the potentiometer acts as an adjustable voltage divider The voltage will thus vary from OV when the tap is at the minimum position and to 5V when the tap is at the maximum position The controller considers 2 5V to be the zero position Motor Off 2 5V is the potentiome ter s mid point position AX1500 Motor Controller User s Manual 115 Analog Control and Operation RoboteQ Internal Resistors and Converter 47kOhm 10kOhm 47kOhm 10kOhm or4 8 Ground FIGURE 76 Potentiometer connection wiring diagram The controller includes two 47K ohm resistors pulling the input to a mid voltage point of 2 5V Whe
83. controller depending on the voltage applied to Power Control and Vmot TABLE 2 Controller Status depending on Power Control and VMot Power Control input is connected to And Main Battery Voltage is Action Ground Any Voltage from OV to 40V Controller is Off Floating OV Controller is Off Not Recom mended Off Configuration Floating Between 8V and 10 5V Controller Logic is On Power Stage is Disabled under voltage condition Floating Between 10 5 and 40V Controller is On Power Stage is Active AX1500 Motor Controller User s Manual 29 Connecting Power and Motors to the Controller RoboteQ TABLE 2 Controller Status depending on Power Control and VMot Power Control input is And Main Battery connected to Voltage is Action 10 5V to 40V OV Controller is On Power Stage is Off 10 5V to 40V 1V to 40V Controller is On Power Stage is Active All 3 ground are connected to each other inside the controller The two main battery wires are also connected to each other internally However you must never assume that connecting one wire of a given battery potential will eliminate the need to connect the other Controller Powering Schemes Powering the Controller from a single Battery The diagram on Figure 11 show how to wire the controller to a single battery circuit and how to turn power On and Off Motor2 Power on off switch Fuse Em
84. counter values are stored as a signed binary numbers ranging from 2 147 836 648 to 2 147 836 647 Hexadecimal format of value 80000000 to 7FFFFFFF respectively When the maximum or minimum counter values are reached the counters automatically roll over to zero The counters can be read and set using the commands described in The contains its own Microcontroller and firmware in Flash When present it responds to a large set of dedi cated commands and queries via the controller s serial port See RS232 Encoder Com mand Set on page 145 on page 78 Using the Encoder to Measure Speed The encoder module will automatically compute rotation speed for each encoder The resulting measured speed is a value ranging from O to 127 and O to 127 where 127 rep resent a relative ratio of a maximum speed value chosen by the user For example if the encoder module is configured so that the highest measured speed value is 3 000 RPM then a reading of 63 127 2 would be 1 500 RPM The relationship between the measured speed and the actual speed is a factor of two vari able parameters a Time Based period value stored inside the Encoder module and the Encoder s number of Pulses per Revolution Note the Encoder s number of Pulses per Revolution is not stored in the controller The Time Base is a number of 256us time intervals between two counter reads 76 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007
85. ctual motor speed If the speed changes because of changes in load the controller automatically compensates the power output This mode is preferred in preci sion motor control and autonomous robotic applications Details on how to wire the tachometer can be found in Connecting Tachometer to Analog Inputs on page 59 Closed Loop Speed control operation is described in Closed Loop Speed Mode on page 93 FIGURE 15 Motor with tachometer or Encoder for Closed Loop Speed operation Close Loop Position Control In this mode illustrated in Figure 16 the axle of a geared down motor is coupled to a potentiometer that is used to compare the angular position of the axle versus a desired position This AX1500 feature makes it possible to build ultra high torque jumbo servos that can be used to drive steering columns robotic arms life size models and other heavy loads Details on how to wire the position sensing potentiometers and operating in this mode can be found in Closed Loop Position Mode on page 81 AX1500 Motor Controller User s Manual 41 General Operation RoboteQ FIGUR Position Feedback Position Sensor Gear box E 16 Motor with potentiometer assembly for Position operation User Selected Current Limit Settings The AX1500 has current sensors at each of its two output stages Every 16 ms this current is measured and a correction to the output power level is applied if higher
86. direction information is returned by this query This query is most useful for providing feedback to a microcontroller commanding the controller Query Amps from Battery to each Motor Channel Description This query will cause the controller to return the actual number of Amps flowing from the battery to power each motor The number is an unsigned Hexadecimal number ranging from 0 to 256 0 to FF in Hexadecimal Syntax aor A Reply nn mm Where nn motor 1 Amps mm motor 2 Amps Notes The Amps measurement has an approximately 10 precision Its main purpose is to pro vide feedback to the controller s current limitation circuitry Important Notice The current flowing in the motor can be higher than the battery flowing out of the battery See Battery Current vs Motor Current on page 43 Important Notice On the AX3500 the number returned by the a command must be divided by four to obtain the actual Amps value 130 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Controller Commands and Queries Query Analog Inputs Description This query will cause the controller to return the values of the signals present at its two analog inputs If the controller is used in close loop speed mode with analog feedback the values represent the actual soeed measured by the tachometer When used in position mode the values represent the actual motor position measured by a potentio
87. dule The measured speed is a relative number ranging from O to 127 The relationship between this relative soeed number and the actual RPM is based on the Time Base value and the Encoder s Pulses Per Revolution PPR value see Using the Encoder to Measure Speed on page 76 for details On this screen changing the Time Base and PPR values automatically display the Max RPM values that can be measured with these settings For example with a default set ting of 16 and 200 for the Time Base and PPR respectively the maximum RPM values is 2188 This means that when the motors rotate at 2188 RPM the measured relative speed is 127 If the motor spins faster the speed is still reported to be 127 Note that the PPR value is not stored in the controller It is used only in Roborun to convert relative speed into actual RPM The Divider parameter is described in Using the Encoder to Track Position on page 77 The threshold level parameter and its operation is described in Voltage Levels Thresholds and Limit Switches on page 72 Exercising the Motors A set of buttons and sliders is provided to start stop communication with the controller and encoder When communication is active the screen will be updated with Encoder data Moving the motor sliders will set the motors to the desired speed and direction Viewing Encoder Data During operation this screen will display the following information e The instantan
88. e Aand B Closed Loop Speed Mixed e A Closed Loop Speed B Position Note that in the last selection only the first motor will operate in the Closed Loop Speed mode Changing the parameter to select this mode is done using the Roborun Utility See Load ing Changing Controller Parameters on page 164 Using Optical Encoder for Speed FeedbackDigital Optical Encod ers may be used to capture accurate motor speed This capability is only available on con trollers fitted with the optional encoder module AX1500 Motor Controller User s Manual 93 Closed Loop Speed Mode RoboteQ Detailed information on how to install and wire optical encoders is provided at Installing Connecting and Using the Encoder Module on page 67 If using optical encoders omit the Analog Tachometer discussion in this section and resume reading from Control Loop Description on page 96 Optical Encoders require special handling See Installing Connecting and Using the Encoder Module on page 67 for a detailed discussion Tachometer or Encoder Mounting Proper mounting of the speed sensor is critical for an effective and accurate speed mode operation Figure 56 shows a typical motor and tachometer or encoder assembly Analog Tachometer or Optical Encoder Speed feedback FIGURE 56 Motor and speed sensor assembly needed for Close Loop Speed mode Tachometer wiring The tachometer must be wired so that it creates a vo
89. e able to receive commands from the PC and the Roborun software will not recognize the controller as being present However when in the Run tab and the Run button activated Roborun will be receiving the strings sent by the controller and display the various parameters in the right display box and chart Loading and Saving Profiles to Disk It is possible to save the configuration parameters that are read from the controller or that have been set changed using the various menus to the disk This function allows easy recall of various operating profiles at a later time without having to remember or manually reset all the parameters that are used from one configuration to another To save a profile to disk simply click on the Save Profile to Disk button You will then be prompted to choose a file name and save Reading a profile from disk is as simple as clicking on the Load Profile from Disk button and selecting the desired profile file The parameters will be loaded in each of their respec tive buttons sliders and text fields on the various Roborun screens The parameter will not be transferred to the controller until you press the Save to Controller button Operating the AX1500 over a Wired or Wireless LAN The Roborun utility supports connection and operation of the AX1500 controller over a Wired or Wireless TCP IP network This feature makes it easy to tele operate and monitor the controller across a lab or across th
90. e globe via Internet 176 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Operating the AX1500 over a Wired or Wireless LAN To operate over the network two computers are required as show in Figure 97 below The top computer is connected to the controller via its COM port Both computers are con nected to a TCP IP network Computer running Roboserver LT Controller Wired or Wireless 802 11 LAN Computer running Psy Roborun Utility SE FIGURE 97 Operating the controller over a LAN The computer connected to the controller must run a communication server program named Roboserver This program is automatically installed in the Start menu when install ing the Roborun utility This program s function it to wait for and accept TCP IP connection requests from the other computer and then continuously move data between the network and the COM port When launched the screen shown below appears The second computer runs the Roborun utility To establish contact with the server pro gram click on the Change COM LAN Port button and enter the IP address of the second computer Communication should be established immediately When the two computers are connected it will be possible to operate the motors and read the controller s operating parameters in the Roborun Run window ioixi Listening to port 1007 Rx Data J Tx Data COM1 Open Host kog IP
91. e is no need to insert a sep arate switch on Power cables although one is suggested for Emergency disconnect See Controller Power on page 28 for a detailed discussion and more wiring options Avoid extending the length of wires from the battery to the controller as the added induc tance may cause damage to the controller when operating at high currents Try extending the motor wires instead since the added inductance on the motor side of the controller is not harmful The two VMot terminals are connected to each other inside the controller The same is true for the Ground Terminals You should wire each pair together as shown in the diagram above 3 The Power control terminal MUST be connected to Ground to turn the Controller Off For turning the controller On even though the Power Control may be left floating when ever possible pull it to an unfused12V or higher voltage to keep the controller logic solidly On You may use a separate battery to keep the controller alive as the main Motor battery discharges Refer to the chapter Connecting Power and Motors to the Controller on page 27 for more information about batteries and other connection options AX1500 Motor Controller User s Manual 17 AX1500 Quick Start IRoboteQ Important Warning Do not rely on cutting power to the controller for it to turn off if the Power Control is left floating If motors are spinning because the robot is pushed are pushed or becau
92. eal 1 0ms to 2 0ms discussed above To make sure that the controller captures the full joystick movement the AX1500 defaults to the timing val ues shown in Figure 70 These vales can be changed and stored as new defaults joystick position min center max R C pulse timing FIGURE 70 Joystick position vs pulse duration default values The AX1500 has a very accurate pulse capture input and is capable of detecting changes in joystick position and therefore pulse width as small as 0 4 This resolution is superior to the one usually found in most low cost R C transmitters The AX1500 will therefore be able to take advantage of the better precision and better control available from a higher quality R C radio although it will work fine with lesser expensive radios as well Internally the measured pulse width is compared to the reference minimum center and maximum pulse width values From this is generated a number ranging from 127 when the joystick is in the min position to O when the joystick is in the center position to 127 when the joystick is in the max position This number is then used to set the motors desired speed or position that the controller will then attempt to reach For best results reliability and safety the controller will also perform a series of correc tions adjustments and checks to the R C commands as described in the following sec tions Reception Watchdog Immediately after it is po
93. ected to each other in the board and must be wired to the same voltage AF VMot M2 M2 3xGnd SC M1 M1 VMot Motor 2 Motor 1 FIGURE 2 AX1500 Controller Rear View 16 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Connecting to the Batteries and Motors Connecting to the Batteries and Motors Connection to the batteries and motors is shown in the figure below and is done by con necting wires to the controller s terminal strip Motor2 Power switch Optional RS Optional Emergency Disconnect 12V to 24V Controller Motor Battery Notes The Battery Power connection are doubled in order to provide the maximum current to the controller If only one motor is used only one set of motor power cables needs to be connected Typically 1 2 or 3 x 12V batteries are connected in series to reach 12 24 or 36V respectively The Power Control wire MUST be used to turn On and Off the controller FIGURE 3 AX1500 Electrical Power Wiring Diagram 1 Connect each motor to one of the two M and M terminal pairs Make sure to respect the polarity otherwise the motor s may spin in the opposite direction than expected 2 Connect two of the three Ground terminals to the minus terminal of the battery that will be used to power the motors Connect the two VMot terminals to the plus terminal of the battery The motor battery may be of 12 to 40 Volts Ther
94. ehicle inverted e General purpose digital input One general purpose 24V 2A output for accessories Up to 2 general purpose digital inputs Optical Encoder Inputs optional Inputs for two Quadrature Optical Encoders up to 250khz Encoder frequency per channel two 32 bit up down counters Inputs may be shared with four optional limit switches per channel Internal Sensors Voltage sensor for monitoring the main 12 to 40V battery system operation Voltage monitoring of internal 12V Temperature sensors on the heat sink of each power output stage Sensor information readable via RS232 port Low Power Consumption On board DC DC converter for single 12 to 40V battery system operation Optional backup power input for powering safely the controller if the motor batteries are discharged Max 200mA at 12V or 100mA at 24V idle current consumption Power Control wire for turning On or Off the controller from external microcomputer or switch No power consumed by output stage when motors are stopped Regulated 5V output for powering R C radio Eliminates the need for separate R C battery High Efficiency Motor Power Outputs Two independent power output stages Optional Single Channel operation at double the current Dual H bridge for full forward reverse operation Ultra efficient 5mOhm ON resistance RDSon MOSFET transistors Synchronous Rectification H Bridge 12 to 40 V operation Terminal strip up to AWG12 high current wire Temperature b
95. eous relative O to 127 speed value e The instantaneous relative distance to destination 0 after reset e The actual speed computed from the measured relative speed value encoder Time Base and Encoder PPR The PPR value must be entered manually on this screen every the utility is run as it is not stored in the controller or on the PC e The Encoder counter values e The status of the optional limit switches Running the Motors The Roborun utility will let you exercise and monitor the motors sensors and actuators using a computer This feature is particularly useful during development as you will be able to visualize in real time the robot s Amps consumption and other vital statistics during actual operating conditions Figure 95 shows the Run Screen and its numerous buttons and dials 170 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ Running the Motors Controls Power Settings R C Ana Specific Close Loop Encoder RC Out Run Console DearLog p Motor M fo BatAmps 740 ae _Save Loa 0 Ch Peak HE Res Timer Ip Mot Amps 100 ira Power 80 d a To at d e CO 40 J Plot 0 2 2 a z m Command 2 M 25 FET Temp 0 r Stop Motor 2 M fo BatAmps 549 e z __9 p ceea a r Input Dumie Voltage jo Mot Amps 100 a ue C fie Bat Volt R 32 Power wi H E EStop inv
96. er 47kOhm Ana 2 10 Ana 3 12 47kOhm Ana4 8 A D 10kOhm 4 7kOhm 47kOhm Ground 5 FIGURE 32 Battery voltage monitoring circuit Using these resistor values it is possible to measure a voltage ranging from 5V to 60V with a 0 25V resolution The formula for converting the A D reading into a voltage value is as follows 62 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Connecting User Devices to Analog Inputs Measured volts controller reading 128 0 255 5 Note The A D converter s reading is returned by the p command and is a signed 8 bit hexadecimal value You must add 128 to bring its range from 127 127 to 0 255 Connecting User Devices to Analog Inputs The two analog inputs can be used for any other purpose The equivalent circuit for each input is shown in Figure 33 The converter operates with an 8 bit resolution reporting a value of 0 at OV and 255 at 5V Care should be taken that the input voltage is always posi tive and does not exceed 5V The converter s intrinsic diodes will clip any negative voltage or voltage above 5V thus providing limited protection The value of the analog inputs can be read through the controller s RS232 port 5V 14 l 47kOhm Ana 1 11 Ana 2 10 Ana 3 12 Ana4 8 10kOhm 47kOhm Ground 5 FIGURE 33 AX1500 Analog Input equivalent circuit Internal Voltage Monitoring Sensors The AX150
97. er value expressed in seconds Command1 127 to 127 Command applied to channel 1 Command2 127 to 127 Command applied to channel 2 AX1500 Motor Controller User s Manual 173 Using the Roborun Configuration Utility RoboteQ TABLE 32 Logged parameters order type and definition Parameter Header Data type range Measured Parameter Power 0 to 127 Amount of power applied to the output stage of chan nel 1 Power2 0 to 127 Same for channel 2 or Temp 1 or Volt 1 Ana 1 Speed 1 Pos 1 127 to 127 Value of sensor connected on analog input 1 Data is automatically converted to the right value and format 40 to 150 j by Roborun according to the sensor that is being used O to 55 Ana 2 Speed 2 Pos 2 127 to 127 Same for channel 2 Temp 2 or 40 to 150 Volt 2 0 to 55 Amps1 0 to 255 Measured Amps on channel 1 Amps2 0 to 255 Measured Amps on channel 2 FET Temp1 40 to 150 Measured Temperature on channel 1 s heatsink FET Temp2 40 to 150 Measured Temperature on channel 2 s heatsink Batt Volt 0 to 55 Main Battery Voltage Ctrl Volt 0 to 28 5 Internal 12V Voltage Enc1 127 to 127 Measured Optical Encoder s Speed or Position depending on selected operating mode Enc2 127 to 127 Same for channel 2 Connecting a Joystick Exercising the motors can easily be done using a Joystick in addition to the on screen slid ers Simply c
98. ergency Disconnect 12V to 24V Controller Motor Battery Notes The Battery Power connection are doubled in order to provide the maximum current to the controller If only one motor is used only one set of motor power cables needs to be connected Typically 1 2 or 3 x 12V batteries are connected in series to reach 12V 24V or 36V respectively FIGURE 9 Powering the AX1500 from a single battery Connect two of the three Ground terminals to the minus terminal of the battery that will be used to power the motors Connect the two VMot terminals to the plus terminal of the battery The motor battery may be of 12 to 40 Volts 30 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Controller Powering Schemes There is no need to insert a separate switch on Power cables although for safety reasons it is highly recommended that a way of quickly disconnecting the Motor Power be provided in the case of loss of control and all of the AX1500 safety features fail to activate The two VMot terminals are connected to each other inside the controller The same is true for the Ground Terminals You should wire each pair together as shown in the diagram above The Power control terminal MUST be connected to Ground to turn the Controller Off When the controller is Off the output transistors are in the Off position and no power is drawn on VMot For turning the controller On even though the Power Control m
99. error occurs the controller will halt permanently until its power is cycled or it is reset An Encoder error is one of the conditions that is sig nalled by the diagnostic LED rapidly flashing see Permanent Faults on page 127 Adding Safety Limit Switches The Position mode depends on the position sensor providing accurate position information If the potentiometer is damaged or one of its wire is cut the motors may spin continuously in an attempt to reach a fictitious position In many applications this may lead to serious mechanical damage To limit the risk of such breakage it is recommended to add limit switches that will cause the motors to stop if unsafe positions have been reached independent of the potentiome ter reading If the controller is equipped with and Encoder module the simplest solution is to imple ment limit switches as shown in Wiring Optional Limit Switches on page 73 This wiring can be used whether or not Encoders are used for feedback If no Encoder module is present an alternate method is shown in Figure 53 This circuit uses Normally Closed limit switches in series on each of the motor terminals As the motor reaches one of the switches the lever is pressed cutting the power to the motor The diode in parallel with the switch allows the current to flow in the reverse position so that the motor may be restarted and moved away from that limit AX1500 Motor Controller User s Manual 87 Clo
100. ery The red wire in the loop must be cut so that the 5V out from the controller does not flow to the radio and so that the battery that is connected to the controller does not inject power into the controller The figure below show the cable with the loop cut Figure 69 shows the equivalent electrical diagram Channel 3 3 Channel 1 Command Pulses 4 Channel 2 Command Pulses 6 Radio battery Ground 7 Radio battery 8 Channel 3 Command Pulses Controller R C Radio Power Power R C Channel 1 Radio Battery R C Radio l R C Channel 2 4 icu R C Channel 3 R C Radio Ground Controller Ground FIGURE 69 Electrical diagram for connection to independently powered RC radio Operating the Controller in R C mode In this operating mode the AX1500 will accept commands from a Radio Control receiver used for R C models remote controls The speed or position information is communicated to the AX1500 by the width of a pulse from the R C receiver a pulse width of 1 0 millisec 106 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRo boteQ Reception Watchdog ond indicates the minimum joystick position and 2 0 milliseconds indicates the maximum joystick position When the joystick is in the center position the pulse should be 1 5ms Note that the real pulse length to joystick position numbers that are generated by your R C radio may be different than the id
101. es 24 SECTION 4 Connecting Power and Motors to the Controller 27 Power Connections 27 Controller Power 28 Controller Powering Schemes 30 Powering the Controller from a single Battery 30 Powering the Controller Using a Main and Backup Battery 31 Connecting the Motors 32 Single Channel Operation 33 Converting the AX1500 to Single Channel 33 Power Fuses 34 Wire Length Limits 34 Electrical Noise Reduction Techniques 35 Power Regeneration Considerations 35 Overvoltage Protection 36 Undervoltage Protection 36 Using the Controller with a Power Supply 36 AX1500 Motor Controller User s Manual IRoboteQ SECTION 5 General Operation 39 Basic Operation 39 Input Command Modes 39 Selecting the Motor Control Modes 40 Open Loop Separate Speed Control 40 Open Loop Mixed Speed Control 40 Closed Loop Speed Control 41 Close Loop Position Control 41 User Selected Current Limit Settings 42 Temperature Based Current Limitation 42 Battery Current vs Motor Current 43 Regeneration Current Limiting 44 Programmable Acceleration 45 Command Control Curves 46 Left Right Tuning Adjustment 47 Activating Brake Release or Separate Motor Excitation 49 Emergency Stop using External Switch 49 Inverted Operation 49 Special Use of Accessory Digital Inputs 50 Using the Inputs to Activate the Buffered Output 50 Using the Inputs to turn Off On the Power MOSFET transistors 50 SECTION 6 Connecting Sensors and Actuators to Input Outputs 5
102. et These parameters are stored in the controller s Flash memory and are not intended to be changed at runtime Important Notice The above parameters are stored in the MCU s configuration flash Their storage is perma nent even after the controller is powered off However because of the finite number of times flash memories can be reprogrammed approx 1000 times these parameters are not meant to be changed regularly or on the fly All parameters in Flash except for the Amps calibration are reset to their default values every time new firmware is loaded into the controller Input Control Mode Address 00 Access Read Write Effective After Reset This parameter selects the method the controller uses for accepting commands Value Mode See pages 0 R C Radio mode default page 101 RS232 no watchdog page 101 2 RS232 with watchdog 3 Analog mode page 113 Motor Control Mode Address 01 Access Read Write Effective After Reset or FF AX1500 Motor Controller User s Manual 135 Serial RS 232 Controls and Operation lRoboteQ This parameters selects the various open loop and closed loop operating modes as well as the feedback method Bit Definition See pages 2 0 Motor Control Mode 0 A amp B separate speed open loop page 40 default page 93 1 A amp B mixed speed open loop page 81 2 Aspeed open loop B position
103. eter Syntax mm Reply DD Where mm address location of parameter DD parameter value 148 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ RS232 Encoder Command Set Example 84 Read value of parameter at address hex 84 01 Controller replies value is 01 Modify parameter Syntax mm nn Reply if command was executed successfully if error Where mm parameter address nn new parameter value Examples 84 03 Store 03 into parameter at address hex 84 Notes All parameters and values are expressed with 2 hexadecimal digits The table below lists maps the few relevant parameters that can be accessed using this command TABLE 28 Encoder Registers Address Parameter Description Size Access 84 Encoder Hardware ID Code 1 byte Full 85 Switches Status 1 byte Full 86 Speed or Distance 1 depending on operating mode 1 byte Full 87 Speed or Distance 2 depending on operating mode 1 byte Full 88 Counter Read Write Mailbox MSB bits 31 to 24 89 Counter Read Write Mailbox bits 23 to 16 4 bytes Full 8A Counter Read Write Mailbox bits 15 to 8 8B Counter Read Write Mailbox LSB bits 7 to 0 8C Counter 1 MSB bits 31 to 24 8D Counter 1 bits 23 to 16 4 bytes Limited 8E Counter 1 bits 15 to 8 8F Counter 1 LSB bits 7 to 0 90 Counter 2 MSB bits 31 to 24 91 Counter 2 bits 23 to 16 4 bytes Limited
104. g Changing Controller Parameters on page 164 See Connecting devices to Output C on page 55 for details on how to connect to the output Emergency Stop using External Switch An external switch can be added to the AX1500 to allow the operator to stop the control ler s output in case of emergency This controller input can be configured as the Inverted detection instead of Emergency Stop The factory default for this input is No Action The switch connection is described in Connecting Switches or Devices to EStop Invert Input on page 57 The switch must be such that it is in the open state in the normal situa tion and closed to signal an emergency stop command After and Emergency Stop condition the controller must be reset or powered Off and On to resume normal operation Inverted Operation For robots that can run upside down the controller can be configured to reverse the motor commands using a gravity activated switch when the robot is flipped This feature is enabled only in the mixed mode and when the switch is enabled with the proper configura tion of the Input switch function parameter See Programmable Parameters List on page 175 The switch connection is described in Connecting Switches or Devices to EStop Invert Input on page 57 The switch must be such that it is in the open state when the robot is in the normal position and closed when inverted When the status of the switch has cha
105. g Speed Sensor connection depending on operating mode Operating Mode Ana 1 p11 Ana2 p10 Ana 3 p12 Ana 4 p8 RC or RS232 Dual Channel Speed 1 Speed 2 Unused Unused Analog Dual Channel Command 1 Command 2 Speed 1 Speed 2 RC or RS232 Single Channel Speed Unused Unused Unused RC or RS232 Dual Channel Command Unused Speed Unused Important Warning The tachometer s polarity must be such that a positive voltage is generated to the controller s input when the motor is rotating in the forward direction If the polarity is inverted this will cause the motor to run away to the maximum speed as soon as the controller is powered with no way of stopping it other than pressing the emer gency stop button or disconnecting the power AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ Connecting External Thermistor to Analog Inputs Connecting External Thermistor to Analog Inputs Using external thermistors the AX1500 can be made to supervise the motor s tempera ture and adjust the power output in case of overheating Connecting thermistors is done according to the diagram show in Figure 30 The AX1500 is calibrated using a 10kOhm Negative Coefficient Thermistor NTC with the temperature resistance characteristics shown in the table below TABLE 11 Recommended NTC characteristics Temp oC 25 0 25 50 75 100 Resistance kOhm 86 39 27 28 10 0
106. gative numbers the Encoder module will insert a O ahead of any number string starting with a digit value higher than 7 i e 8 to F to signify that the number is positive For negative numbers the Encoder module will insert an F ahead of any number string starting with a digit value lower than 8 i e O to 7 The table below shows examples of this scheme as applied to various counter values TABLE 29 Example counter values and RS232 output using a reduction scheme Decimal 32 bit Hex Controller Output 5 00000005 5 250 000000FA OFA 6 FFFFFFFA A 235 FFFFFF15 F15 91 011 186 056CB872 56CB872 7 986 091 FF862455 862455 When reading the counter value into a microcomputer the reverse operation must take place any output that is less than 8 digit long must be completed with a string of O s if the first digit is of value O to 7 or with a string of F s if the first digit is of value 8 to F The resulting Hex representation of a signed 32 bit number must then be converted to binary or decimal as required by the application The burden of this extra processing is more than offset by the bandwidth relief on the con troller s serial port Encoder Testing and Setting Using the PC Utility Extensive diagnostic calibration setting and testing support is provided in the Roborun PC utility Basic instructions on how to install and run the PC utility can be found in Using the Roborun Configuration Uti
107. gh current applications it is possible that the controller may heat up faster and to a higher temperature than can be dissipated by the using natural convection alone In these applications you should ensure that air flow exists to remove the heat from the heat sink In the most extreme use you should consider using an external fan to circulate air around the controller Attaching the Controller Directly to a Chassis The AX1500 can be attached to a metal chassis to improve heat dissipation For this pur pose the board has holes at the corners of the PCB which can be used to fasten it to the chassis Of course first it is necessary to remove the blue heat sink which is mounted as standard A total of 6 screws for the AX1500 are required four on the corners and two in the heat sink area In order to avoid that components leads sticking out the back of the PCB make contact with the chassis it is needed to interpose a metal bar interposer of thickness sufficient to distance the PCB from the surface of the chassis AX1500 Motor Controller User s Manual 183 Mechanical Specifications IRo b oteQ Note that the back of the PCB has large copper areas exposed just under the power MOS Board Thermal Pad Metal Interposer Metal Chassis Spacer FIGURE 104 Mount the controller without heatsink against a chassis area It is critical that the interposer either is insulated example anodized aluminum or a layer of t
108. gned and 1 to 128 signed decimal to hexadecimal conversion table UDec Dec Hex UDec Dec Hex UDec Dec Hex UDec Dec Hex m28 128 lso 96 160 ao 64 192 CO 32 224 E0 127 129 81 95 161 A1 63 193 C1 31 225 E 126 130 82 94 162 A2 62 194 C2 30 226 E 125 131 83 93 163 A3 61 195 C3 29 227 z 124 132 84 92 164 A4 60 196 C4 28 228 E 123 133 85 91 165 A5 59 197 C5 27 229 E 122 134 86 90 166 A6 58 198 C6 26 230 E 158 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ Decimal to Hexadecimal Conversion Table TABLE 31 128 to 255 unsigned and 1 to 128 signed decimal to hexadecimal conversion table UDec Dec Hex UDec Dec Hex UDec Dec Hex UDec Dec Hex 121 135 87 89 167 A7 57 199 C7 25 231 E 120 136 88 88 168 A8 56 200 C8 24 232 E8 119 137 89 87 169 A9 55 201 c9 28 233 E 118 138 8A 86 170 AA 54 202 CA 22 234 E 117 139 8B 85 171 AB 53 203 CB 21 235 E 116 140 8C 84 172 AC 52 204 CC 20 236 E 115 141 8D 83 173 AD 51 205 CD 19 237 E 114 142 8E 82 174 AE 50 206 CE 18 238 E 113 143 8F 81 175 AF 49 207 CF 17 239 E 112 144 90 80 176 BO 48 208 DO 16 240 FO 111 145 91 79 177 B1 47 209 D1 15 241 F1 110 146 92 78 178 B2 46 210 D2 14 242 F2 109 147 93 77
109. hannel 1 is configured in Closed Loop sensing Position Control with Analog command and Ana log feedback User Read value with serial command RS232 defined Analog In 4 Analog Input 4 Same as Analog 3 but for Channel 4 AX1500 Motor Controller User s Manual 53 RoboteQ Connecting Sensors and Actuators to Input Outputs I O List and Pin Assignment The figure and table below lists all the inputs and outputs that are available on the AX1500 FIGURE 22 Controller s DB15 connector pin numbering TABLE 8 DB15 connector pin assignment Pin Input or Signal depending Number Output on Mode Description 1 and9 Output Output C 2A Accessory Output C R C Data Out RS232 Data Logging Output 2 Output RS232 Data Out RS232 Data Out Analog Data Out RS232 Data Logging Output R C Ch 1 R C radio Channel 1 pulses 3 Input RS232 Data In RS232 Data In from PC MCU Analog Unused Unused R C Ch 2 R C radio Channel 2 pulses 3 me RS232 Analog Input F_ Digital Input F readable RS232 mode Dead man switch activation 5 and 13 Power Out Ground Controller ground 6 Unused Unused Unused 7 Unused Unused Unused E R C Ch 3 R C radio Channel 3 pulses 3 M RS232 Input E Ana in Accessory input E i 9 4 Dead man Switch Input Activate Output C Analog Input 4 Ana Input E Ana in 4 Accessory input E Dead man Switch Input Activate Output C Channel 2 speed or positio
110. he controller is in the RS232 mode with the watchdog enabled then after 1 second of inactivity motors will be stopped if they were one and a W character will be sent to the terminal When this checkbox is checked Roborun will send a Null character to the control ler on a regular basis so that the watchdog time out is never reached AX1500 Motor Controller User s Manual 175 Using the Roborun Configuration Utility lRoboteQ 4 Send Reset String Clicking this button while the controller is in RS232 mode will cause the reset string to be sent to the controller 5 Send 10 Carriage Returns Clicking this button will cause Roborun to send ten consecutive Carriage Return charac ter If the controller is configured in Analog or RC mode the Carriage Returns will cause it to switch to RS232 mode until the controller is reset again Viewing and Logging Data in Analog and R C Modes When the controller is configured in R C or Analog mode it will automatically and continu ously send a string of ASCII characters on the RS232 output Analog and R C Modes Data Logging String Format on page 156 shows the nature and format of this data This feature makes it possible to view and log the controller s internal parameters while it is used in the actual application The data may be captured using a PC connected to the controller via an RS232 cable or wireless modem When wired for R C or Analog controls the AX1500 will not b
111. hen checked Roborun will capture all the parameters and save them in local RAM The data is not saved to disk until the Save to Disk button is pressed Data is being captured for as long as the program is in the Run mode whether or not a motor command is applied 2 Clear Log This button can be pressed at any time to clear the local RAM from its content Clearing the log also has the effect of resetting the timer 3 Log Fill Status This gray text box indicates whether the local RAM log is empty full or in between 4 Reset Timer button The timer automatically runs when the Run button is pressed and data is being exchanged with the controller regardless of whether or not logging is activated This button resets the timer 5 Save Log to Disk button Pressing this button will prompt the user to select a filename and location where to copy the logged data The file format is a regular text file with each parameter saved one after the other separated by a coma The file extension automatically defaults to csv coma separated values so that the data can be imported directly into Microsoft Excel The first line of the save file contains the Header names Each following line contains a complete set of parameters The Header name order and parameter definition is shown in Table 32 TABLE 32 Logged parameters order type and definition Parameter Header Data type range Measured Parameter Seconds Integer Tim
112. hermal conducting but electrically insulating pad is used Failure to do so will cause a short among the drains of the power MOS and the board will fail Ordinary thermal grease will not act as an insulator The interposer has to be planar so to ensure good thermal contact wit all power MOS in alternative use thermal conducting pad that will fill all the voids between the board and the interposer Precautions to observe Use plastic washers for the screws securing the board to the interposer similar to the ones originally installed They will prevent the head of the screw from touching the heat sinks of the power MOS an from damaging the PCB and making contact with the copper layers underneath Should the board be expected to experience heavy vibrations then use plastic shoulder washer which will keep the stem of the screws centered Make sure the screws holding the corners do not bend the board which remains flat The screws that should hold securely the PCB are the ones in the power MOS area where the best contact is needed for efficient heat transfer The four screws at the corners do not need to be tightened excessively and they also require a plastic washer to avoid damage to the PCB It is a good practice to use nylon screws 8 32 minimum size for electrical isolation and to allow some elasticity in case of vibrations At the end of the assembly process check that there is no electrical continuity between any of the power con
113. his parameter enables and configures the effect of the controller s Digital Inputs and other settings Bit Definition See pages 1 0 Enable and 00 Input Disabled default page 49 Configure 01 Input as Emergency Stop page 49 Invert Estop i 10 Disabled 11 Input as Invert Command 2 Output C when 0 No Action default page 49 Motor On 1 Output C On when either motor is On 3 Encoder Safety 0 No Action default page 72 1 Disables Controller if Encoder detects no movement while power is applied to the motors AX1500 Motor Controller User s Manual 137 Serial RS 232 Controls and Operation lRoboteQ Bit Definition See pages 5 4 Input E Unavailable when Encoder Module is page 50 present page 50 00 No action default 01 Cut FET power when Input E is Low 10 Activate output C 11 Cut FET when Input E is High 7 6 Input F 00 No action default page 50 01 Cut FET power when Input E is Low page 50 10 Activate output C 11 Cut FET when Input E is High RC Joystick or Analog Deadband Address Access Effective A06 Read Write After Reset or AFF This parameter configures the amount of joystick or potentiometer motion can take place around the center position without power being applied to the motors Bit Definition See pages 7 0 Values are for Joystick deadband page 108 0 no deadband or 1 8 page 117 2 16 default 3
114. ically select one power source over the other letting through the source that is higher than the other AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ Controller Power Mot1 Mot1 5Vmin VBatt Vmot Channel 1 MOSFET Power Stage Ness pra Power l i amp Backu l MOSFET Drivers C 13V max o s min L ag P diii 40V max GND i GND Channel 2 MOSFET Power Stage Pn VBatt Vmot Mot2 Mot2 FIGURE 8 Representation of the AX1500 s Internal Power Circuits When powered only via the Power Control input the controller will turn On but motors will not be able to turn until power is also present on the VMot terminals The Power Control input also serves as the Enable signal for the DC DC converter When floating or pulled to above 1V the DC DC converter is active and supplies the AX1500 s microcomputer and drivers thus turning it On When the Power Control input is pulled to Ground the DC DC converter is stopped and the controller is turned Off The Power control terminal MUST be connected to Ground to turn the Controller Off For turning the controller On even though the Power Control may be left floating whenever possible pull it to an unfused12V or higher voltage to keep the controller logic solidly On You may use a separate battery to keep the controller alive as the main Motor battery dis charges The table below shows the state of the
115. ick Center 1 MS 13 Joystick Center 1 LS 14 Joystick Center 2 MS 15 Joystick Center 2 LS 416 Joystick Min 1 MS 17 Joystick Min 1 LS 18 Joystick Min 2 MS 19 Joystick Min 2 LS 1A Joystick Max 1 MS 1B Joystick Max 1 LS 140 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Reading amp Changing Operating Parameters at Runtime A1C Joystick Max 2 MS 41D Joystick Max 2 LS Effective Instantly These parameters are the Gains values that are loaded after the controller is reset or pow ered on These Gains apply to both channels Gains can be changed at Runtime and values can be different for each channel using separate commands see page 142 Gains values are integer number from 0 to 63 This number is divided by 8 internal so that each increment equals 0 125 Bit 7 0 Definition 8 bit value Two registers used to form one 16 bit number for each Joystick parameter Default values in decimal See pages page 110 Min 4400 Center 1600 Max 3200 Reading amp Changing Operating Parameters at Runtime It is possible to change several of the controller s operating modes on the fly during nor mal operation Unlike the Configuration Parameters that are stored in Flash see above the Operating Parameters are stored in RAM and can be changed indefinitely After reset the Operating Parameters are loaded with the values stored in the Configura
116. ield shows that data is being sent then the controller is Off or possibly defective Try resetting the controller and pressing the Run Stop button These two fields are provided for quick diagnostic Use the Console Tab for full visibility on the data exchange between the controller and the PC 6 Input Status and Output Setting This section includes two check boxes and three color squares The check marks are used to activate either of the controller s two outputs The color blocks reflect the status of the three digital inputs present on the controller Black represents a O level Green repre sents a 1 level 172 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRo boteQ Running the Motors 7 Data Logging and Timer A timer is provided to keep track of time while running the motors An additional set of but tons and displays are provided to operate a data logger The data logger is fully described in the section that follows 8 Joystick Enable Enable and configure a joystick Logging Data to Disk While running the motors it is possible to have Roborun capture all the parameters that were displayed on the various fields and charts and save them to disk The log function is capable of recording 32 000 complete sets of parameters which adds up to approximately 30 minutes of recording time The figure below details the buttons and check boxes needed to operate this function 1 Log Check Box W
117. in this mode Mode Description In this mode the axle of a geared down motor is coupled to a position sensor that is used to compare the angular position of the axle versus a desired position The controller will move the motor so that It reaches this position This unique feature makes it possible to build ultra high torque jumbo servos that can be used to drive steering columns robotic arms life size models and other heavy loads The AX1500 incorporates a full featured Proportional Integral Differential PID control algorithm for quick and stable positioning Selecting the Position Mode The position mode is selected by changing the Motor Control parameter in the controller to either e A Open Loop Speed B Position e A Closed Loop Speed B Position e Aand B Position Note that in the first two modes only the second motor will operate in the Position mode Changing the parameter is best done using the Roborun Utility See Loading Changing Controller Parameters on page 164 For safety reasons and to prevent this mode from being accidentally selected Position modes CANNOT be selected by configuring the controller using the built in switches and display AX1500 Motor Controller User s Manual 81 Closed Loop Position Mode RoboteQ Position Sensor Selection The AX1500 may be used with the following kind of sensors e Potentiometers e Hall effect angular sensors e Optical Encoders with Encoder
118. includes a Terminal Emula tion Console for communicating with the controller using raw data See Using the Con sole on page 174 In all cases immediately after reset or power up the controller will output a short identity message followed by a software revision number and software revision date as follows Roboteq v1 9b 06 01 07 s The letter below the prompt message is a code that provides information on the hardware and can be ignored goboted v1 8 03 06 03 pane If in R C or Analog mode type the Enter key 10 times to switch to RS232 mode and display the OK prompt Connected 0 00 10 uto detect i9600 7 6 3 FIGURE 82 Poweron message appearing on Hyperterm RS232 Communication with the Encoder Module The Encoder Module contains its own Microcontroller and firmware in Flash The Encoder s MCU communicates with the one on the main board of the controller During normal operations the two MCUs exchange information as needed transparently to the user During a short time at power up however the Encoder s MCU will send data to the main serial port The sent data is a separate prompt message which e Announces the presence of the encoder MCU e Outputs its software revision and date e Outputs a code identifying the module s hardware ID The serial port settings are described in Serial RS 232 Controls and Operation on page 121 AX1500 Motor Controller User s Manual 125 Serial R
119. ing the RS232 in this way See RS 232 Watchdog on page 128 When reset again the controller will revert to the R C mode or Analog mode unless the Input Mode parameter has been changed in the meantime Data Logging String in R C or Analog mode If the controller is in the R C or analog mode immediately after reset it will send a continu ous string of characters one character every 8ms one entire string every 200ms contain ing operating parameters for data logging purposes This information can be safely ignored and the controller will still be able to switch to RS232 mode upon receiving 10 continuous Carriage Returns as described above The format of the data logging string and it content is described in Figure Analog and R C Modes Data Logging String Format on page 156 126 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Commands Acknowledge and Error Messages RS232 Mode if default If the controller is configured in RS232 mode it will automatically be in the RS232 mode upon reset or power up In this case the OK message is sent automatically indicating that the controller is ready to accept commands through its serial port Commands Acknowledge and Error Messages The AX1500 will output characters in various situations to report acknowledgements or error conditions as listed below Character Echo At the most fundamental level the AX1500 will echo back to the
120. ing the Encoder to Track Position on page 77 Syntax d or D Reply nn mm Where nn distance 1 value mm distance 2 value Notes The command returns a signed hexadecimal number where 0 to 127 is represented by 00 to 7F and 1 to 127 is represented by FF to 80 respectively The hexadecimal format is intended to be deciphered by a microcontroller When exercising the controller manually you may use the Decimal to Hexadecimal conversion table on page 157 Read Speed Distance Description This query is will cause the controller to return either the speed or the distance computed by the Encoder module depending on the operating mode that is selected This command is similar to either of the two previous ones except that it is read from a different location inside the controller and is a filtered value that smoothened abrupt changes Syntax k or K Reply nn mm Where nn speed 1 or distance 1 value mm speed 2 or distance 2 value Read Encoder Limit Switch Status Description This query will cause the controller to return the status of the four optional Encoder limit switches The returned value is a two digit 8 bit Hexadecimal number of which the each of the 4 least significant bit represents one of the hardware switches Note that for this function to work limit switches must be connected to the encoder mod ule using the special wiring diagram show in Wiring Optional Limit Switches on page 73 If no lim
121. ing the motor when a limit is reached while allowing motion in the other direction away for that limit TABLE 13 Effects of Limit Switches 1 and 2 on Motor 1 SwW1 SW2 Motor 1 Fwd Motor 1 Rev OFF OFF Allowed Allowed ON OFF Stopped Allowed OFF ON Allowed Stopped ON ON Stopped Stopped TABLE 14 Effects of Limit Switches 3 and 4 on Motor 2 SW3 SW4 Motor 2 Fwd Motor 2 Rev OFF OFF Allowed Allowed ON OFF Stopped Allowed AX1500 Motor Controller User s Manual Installing Connecting and Using the Encoder Mod RoboteQ TABLE 14 Effects of Limit Switches 3 and 4 on Motor 2 SW3 SW4 Motor 2 Fwd Motor 2 Rev OFF ON Allowed Stopped ON ON Stopped Stopped In Single Channel Mode limit switches 3 and 4 are used This is to allow direct connection of an encoder on the inputs for channel 1 and direct connection of switches on the inputs for channel 2 TABLE 15 Effects of Limit Switches 3 and 4 on Motor 2 in Single Channel Configuration sw3 Sw4 Motor Fwd Motor Rev OFF OFF Allowed Allowed ON OFF Stopped Allowed OFF ON Allowed Stopped ON ON Stopped Stopped Using the Encoder Module to Measure Distance As the encoders rotate their quadrature outputs is automatically processed and incre ments decrements two 32 bit counter inside the Encoder Module There is one 32 bit counter for each of the encoders The
122. ired position set by the user and the actual position captured by the position sensor Figure 55 shows a representation of the PID algorithm Every 16 milliseconds the control ler measures the actual motor position and substracts it from the desired position to com pute the position error The resulting error value is then multiplied by a user selectable Proportional Gain The resulting value becomes one of the components used to command the motor The effect of this part of the algorithm is to apply power to the motor that is proportional with the dis tance between the current and desired positions when far apart high power is applied with the power being gradually reduced and stopped as the motor moves to the final posi tion The Proportional feedback is the most important component of the PID in Position mode AX1500 Motor Controller User s Manual 89 Closed Loop Position Mode lRoboteQ A higher Proportional Gain will cause the algorithm to apply a higher level of power for a given measured error thus making the motor move quicker Because of inertia however a faster moving motor will have more difficulty stopping when it reaches its desired position It will therefore overshoot and possibly oscillate around that end position Proportional Gain Desired Position Output Analog Position Sensor D Measured Position or Optical Encoder FIGURE 55 PID algorithm used in Position mode Integ
123. is that it depends on the controller to be fully functioning and that once a switch is activated the controller will remain inactive until the switch is released In most situations this will require manual intervention Another limita tion is that both channels will be disabled even if only one channel caused the fault AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Using Current Limiting as Protection Manual Emergency Stop Switch Ground Emergency Stop Input Controller FIGURE 54 Safety limit using AX1500 s Emergency Stop input Important Warning Limit switches must be used when operating the controller in Position Mode This will significantly reduce the risk of mechanical damage and or injury in case of dam age to the position sensor or sensor wiring Using Current Limiting as Protection It is a good Idea to set the controller s current limit to a low value in order to avoid high cur rent draws and consequential damage in case the motor does not stop where expected Use a value that is no more than 2 times the motor s draw under normal load conditions Control Loop Description The AX1500 performs the Position mode using a full featured Proportional Integral and Dif ferential PID algorithm This technique has a long history of usage in control systems and works on performing adjustments to the Power Output based on the difference measured between the des
124. is will cause the motor to rotate in the opposite direction Voltage Levels Thresholds and Limit Switches The encoder module s input uses a comparator to reshape the encoder s output signal If the signal is below a programmable threshold level then it is considered to be 0 If above it is considered to be 1 The output of this comparator feeds the quadrature detector and counters On the Encoder module the threshold voltage may be changed under software control to any value between 0 and 5V in order to meet unusual encoder specifications By default the threshold level is 2 5V Another set of comparators on the same input signals detects pulses that are above and below a fixed 0 5V threshold Using a special circuitry for creating multi level signaling see next section below the output of these comparators serves to detect the status of optional limit switches Figure 43 and Figure 42 show the conditioned signals as seen by the encoder In Figure 43 the encoders are connected directly to the Channel A and B inputs In this case it will cause a Switch Detection condition because the encoder s 0 level is below 0 5V which should be ignored AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Wiring Optional Limit Switches Signal on Channel A or Bo E 4 J 4 I Ly lp 25V 0 5V Quadrature Signal Switch Detect Signal Not meaningful Jd d FIGURE 42
125. ist on page 175 and Loading Changing Con troller Parameters on page 164 for details on how to adjust this parameter The Left Right adjustment is performed in addition to the other command curves described in this section This adjustment is disabled when the controller operates in any of the sup ported closed loop modes TABLE 6 Left Right Adjustment Parameter selection Parameter Value Speed Adjustment Parameter Value Speed Adjustment 7 None default 0 5 25 8 0 75 1 4 5 9 1 5 2 3 75 10 2 25 3 3 11 3 4 2 25 12 3 75 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Activating Brake Release or Separate Motor Excitation TABLE 6 Left Right Adjustment Parameter selection Parameter Value Speed Adjustment Parameter Value Speed Adjustment 5 1 5 12 4 5 6 0 75 14 5 25 Activating Brake Release or Separate Motor Excitation The controller may be configured so that the Output C will turn On whenever one of the two motors is running This feature is typically used to activate the mechanical brake release sometimes found on motors for personal mobility systems Likewise this output can be used to turn on or off the winding that creates the armature s magnetic field in a separate excitation motor This function is disabled by default and may be configured using the Roborun PC utility See Loadin
126. it switches are present this query will return the logic levels of each of the encoder s quadrature outputs which in most cases is not relevant information Syntax w or W AX1500 Motor Controller User s Manual 147 lRoboteQ Reply On Where n switch status The relationship between the value of n and the switch status is shown in the table below Extracting the status of a given switch from this number is easily accomplished in software using masking TABLE 27 Reported value and switch status relationship Switch Switch n Value n Value 4 3 2 1 4 3 2 0 0 0 0 0 8 1 0 0 0 0 0 0 9 1 0 0 1 2 0 0 1 0 A 1 0 1 0 3 0 0 1 1 B 1 0 1 1 4 0 1 0 0 G 1 1 0 0 5 0 1 0 1 D 1 1 0 1 6 0 1 1 0 E 1 1 1 0 7 0 1 1 1 F 1 1 1 1 Note that the 0 and 1 levels represent a Closed Switch and Open Switch status respec tively Read Modify Encoder Module Registers and Parameters Description These commands make it possible to examine and change parameters that are stored in the Encoder s module MCU RAM While this command provides unrestricted access to up to 256 memory locations a small number of these locations should never be read or altered Parameter address and returned values are two digit Hexadecimal numbers 8 bit Important Note Command character has been changed from to starting in version 1 7 of the controller firmware Read param
127. ity see Using the Roborun Configuration Utility on page 161 and following these steps 1 Disconnect the controller s Motor Power 2 Configure the controller in Open Loop Mode using the PC utility This will cause the motors to run in Open Loop for now 3 Launch the Roborun utility and click on the Run tab Click the Start button to begin communication with the controller The tachometer values will be displayed in the appropriate Analog input value boxe s which will be labeled Ana 1 and Ana 2 If encoders are used look for the reported speed value in the Enc boxes 4 Verify that the motor sliders are in the 0 Stop position 5 If a tachometer is used verify that the measured speed value read is 0 when the motors are stopped If not trim the O offset potentiometer 6 Apply power to the Motor Power wires The motor will be stopped 7 Move the cursor of the desired motor to the right so that the motor starts rotating and verify that a positive speed is reported Move the cursor to the left and verify that a negative speed is reported 8 If the tachometer or encoder polarity is the same as the applied command the wir ing is correct 9 If the tachometer polarity is opposite of the command polarity then either reverse the motor s wiring or reverse the tachometer wires If an encoder is used swap its CHA and ChB outputs 10 If a tachometer is used proceed to calibrate the Max Closed Loop speed
128. larly useful during development as you will be able to visualize in real time the robot s Amps consumption and other vital statistics during actual operating conditions Figure 95 shows the Console Screen and its various components Controls Power Settings R C Ana Specific Close Loop Encoder RC Out Run Console Keep Watchdog Alive I Srrrrrr RoboteQ vi1 9b 05 27 07 s RoboEnc vw1 7 02 01 05 13 OK Send Enter x 10 2 Send Reset Switch to R5232 Send 4 QO FIGURE 96 Raw ASCII data exchange in Console 1 Terminal Screen This area displays the raw ASCII data as it comes out of the controller After the controller is reset it will output a prompt with the firmware s revision and date Then if in the RC or Analog mode the controller will output a continuous string of characters for data logging If in RS232 mode the controller will output an OK prompt and is ready to accept com mands 2 Command Entry This window is used to prepare up to 3 command string and send them by clicking on their associated buttons The string is sent to the controller when clicking on the send button Commands can only be sent when the controller has entered in RS232 mode See Con troller Commands and Queries on page 128 for the complete list of commands and que ries See RS232 Encoder Command Set on page 145 for the list of Encoder related commands and queries 3 Keep Watchdog Alive If t
129. ler User s Manual 19 AX1500 Quick Start RoboteQ Powering On the Controller Important reminder There is no On Off switch on the controller You must insert a switch on the controller s power terminal as described in section Connecting to the Batteries and Motors on page 17 To power the controller center the joystick and trims on the R C transmitter In Analog mode center the command potentiomenter or joystick Then turn on the switch that you have placed on the on the Power Control input A Power LED located next to the 15 pin connector will lit to indicate that the controller is ON The status LED will start flashing a pattern to indicate the mode in which the controller is in BEEEEEEEEEEEEEE RC Mode BEEBE RS232 Mode No Watchdog BREE RS232 Mode with Watchdog BEEEEEREEREEREERE Analog Mode FIGURE 5 Status LED Flashing pattern during normal operation Default Controller Configuration Version 1 9b of the AX1500 software is configured with the factory defaults shown in the table below Although Roboteq strives to keep the same parameters and values from one version to the next changes may occur from one revision to the next Make sure that you have the matching manual and software versions These may be retrieved from the Roboteg web site TABLE 1 AX1500 Default Settings Parameter Default Values Letter Input Command mode 0 R C Radio mode Motor Control mode
130. lity on page 161 AX1500 Motor Controller User s Manual 153 lRoboteQ 154 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Automatic Switching from RS232 to RC Mode Automatic Switching from RS232 to RC Mode In many computer controlled applications it may be useful to allow the controller to switch back to the RC mode This would typically allow a user to take over the control of a robotic vehicle upon computer problem While the AX1500 can operate in either RC Radio or RS232 mode the RS232 Data Input and RC Pulse Input 1 share the same pin on the connector External hardware is therefore needed to switch this pin from the RS232 source or the RC Radio The diagram in Figure 84 shows the external hardware required to perform such a switch A third RC channel is used to activate a dual throw relay When the radio is Off or if it is On with the channel 3 off the relay contact brings the RS232 signal to the shared input The second relay contact maintains the Power Control wire floating so that the controller remains on When the RC channel 3 is activated the relay turns On and brings the RC radio signal 1 to the shared input The second relay contact brings a discharged capacitor onto the Power Control wire causing the controller to reset Resetting the controller is necessary in order to revert the controller in the RC mode the controller must be configured to default to RC mode
131. llRoboteQ AX1500 Dual Channel Digital Motor Controller User s Manual v1 9b June 1 2007 visit www roboteq com to download the latest revision of this manual Copyright 2003 2007 Roboteg Inc lRoboteQ AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ Revision History Revision History Date Version Changes June 1 2007 1 9b Added Output C active when Motors On Fixed Encoder Limit Switches Protection in case of Encoder failure in Closed Loop Speed Added Short Circuit Protection with supporting hardware Added Analog 3 and 4 Inputs with supporting hardware Added Operating Mode Change on the fly Changeable PWM frequency Selectable polarity for Dead Man Switch Modified Flashing Pattern Separate PID Gains for Ch1 and C2 changeable on the fly Miscellaneous additions and correction Added Amps Calibration option January 10 2007 1 9 Changed Amps Limit Algorithm Miscellaneous additions and correction Console Mode in Roborun March 7 2005 1 7b Updated Encoder section February 1 2005 1 7 Added Position mode support with Optical Encoder Miscellaneous additions and corrections April 17 2004 1 6 Added Optical Encoder support March 15 2004 1 5 Added finer Amps limit settings Enhanced Roborun utility August 25 2003 1 3 Added Closed Loop Speed mode Added Data Logging support Removed RC monitoring August 15 2003 1 2 Modified to cove
132. ller s firmware with default settings that are different than those chosen by Roboteg This capability can be used to improve system reli ability in the unlikely but not impossible occurrence of a parameter loss in the controller s non volatile memory Should such an event occur the controller would revert to the defaults required by the application pObject Maker lol x RoboteQ sisan Create new object file incorporating your custom settings as new factory defaults Input Object File Seea C servosoft servo roboup 4 021 804 obj Version RoboteQ v1 4 02 18 04 r Settings Profile File Seed C servosoft servo profile monstergarage 092903 pf m New Object File Choose Sub Version Letter fi Ea New Version RoboteQ v1 4 02 18 04 none Create FIGURE 99 Objectmaker creates controller firmware with custom defaults Creating a custom object file can easily be done using the Objectmaker utility This short program is automatically installed in the Start menu when installing the Roborun utility 1 Use the Roborun utility to create and save to disk a profile with all the desired param eter value Launch Objectmaker from the Start menu Select the latest official controller firmware issued by Roboteq Select the profile file that was created and saved earlier Select a revision letter This letter will be added at the end of Roboteq s own version identity number
133. ller while the new program is loading into Flash memory 6 After a verification you will be notified that the operation was successful and you will see the new software revision and date as reported by the controller Notes The Updating utility will automatically detect whether the new software is intended for the main or encoder s MCU and program one or the other accordingly It is a good idea to load the controller s parameters into the PC and save them to disk prior to updating the software After the new software in transferred to the controller you can use the Load Parameters from Disk function and transfer them to the controller using the Save to Controller button Updating the Encoder Software The Encoder Module has its own dedicated MCU and software in Flash memory It may be updated using the Roborun Utility in the same manner as for updating the controller s soft ware see Updating the Controller s Software on page 178 Then select the new soft ware file to download The file s content automatically identifies it as software for the Encoder MCU rather that the Controller s MCU Important Warning 178 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Creating Customized Object Files Do not reinstall the same firmware version as the one already installed in the encoder module Creating Customized Object Files It is possible to create versions of the contro
134. load moved by the motor is not fixed the PID must be tuned with the minimum expected load and tuned again with the maximum expected load Then try to find values that will work in both conditions If the disparity between minimal and maximal possible loads is large it may not be possible to find satisfactory tuning values Note that the AX1500 uses one set of Proportional Integral and Differential Gains for both motors and therefore assumes that similar motors mechanical assemblies and loads are present at each channel AX1500 Motor Controller User s Manual 91 Closed Loop Position Mode lRoboteQ 92 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Mode Description SECTION 9 Closed Loop Speed Mode This section discusses the AX1500 Close Loop Speed mode Mode Description In this mode an analog or digital soeed sensor measures the actual motor speed and com pares it to the desired speed If the speed changes because of changes in load the control ler automatically compensates the power output This mode is preferred in precision motor control and autonomous robotic applications The AX1500 incorporates a full featured Proportional Integral Differential PID control algorithm for quick and stable speed control Selecting the Speed Mode The speed mode is selected by changing the Motor Control parameter in the controller to either e Aand B Closed Loop Speed Separate
135. ltage at the controller s analog input that is proportional to rotation speed OV at full reverse 5V at full forward and 0 when stopped Connecting the tachometer to the controller is as simple as shown in the diagram below Internal Resistors and Converter 1kOhm Max Speed Adjust 10kOhm pot 47kOhm Zero Adjust 100 Ohm pot 10kOhm 47kOhm 1kOhm Ground 5 FIGURE 57 Tachometer wiring diagram 94 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Speed Sensor and Motor Polarity Speed Sensor and Motor Polarity The tachometer or encoder polarity i e which rotation direction produces a positive of negative speed information is related to the motor s rotation speed and the direction the motor turns when power is applied to it In the Closed Loop Speed mode the controller compares the actual speed as measured by the tachometer to the desired speed If the motor is not at the desired speed and direc tion the controller will apply power to the motor so that it turns faster or slower until reached Important Warning If there is a polarity mismatch the motor will turn in the wrong direction and the speed will never be reached The motor will turn continuously at full speed with no way of stopping it other than cutting the power or hitting the Emergency Stop but tons Determining the right polarity is best done experimentally using the Roborun util
136. m 11 8 IntWolt ify Ana2 J 60 I oure soe js 40 J Config Ffo Enc 20 5 omm Error T 25 FET Temp 0 TT Ts fa pOOFF A00 B00 FIGURE 95 Motor exercising and monitoring screen 1 Run Stop Button This button will cause the PC to send the run commands to the controller and will update the screen with measurements received from the controller When the program is running the button s caption changes to Stop Pressing it again will stop the motors and halt the exchange of data between the PC and the controller If another tab is selected while the program is running the program will stop as if the Stop button was pressed 2 Motor Power setting This sub frame contains a slider and several buttons Moving the slider in any direction away from the middle stop position will cause a power command to be issued to the con troller The value of the command is shown in the text field below the slider The stop button will cause the slider to return to the middle stop position and a 0 value command to be sent to the controller The and buttons will cause the slider to move by 1 or 10 power positions respectively 3 Measurement These series of fields display the various operating parameters reported in real time by the controller The Amps field reports the current measured at each channel The Peak Amps field will store the highest measured Amp value from the moment the program began or f
137. meter In all other modes the values represent the measured voltage 0 to 5V applied to the analog inputs The values are signed Hexadecimal numbers ranging from 127 to 127 The 127 value represents OV at the input the O value represents 2 5V and the 127 value repre sents 5V Analog 1 and 2 Syntax p or P Analog 3 and 4 Syntax ror R Reply nn mm Where nn analog input 1 or 3 value speed or position mm analog input 2 or 4 value speed or position Notes The command returns a signed hexadecimal number where 0 to 127 is represented by 00 to 7F and 1 to 127 is represented by FF to 80 respectively Query Heatsink Temperatures Description This query will cause the controller to return values based on the temperature measured by internal thermistors located at each heatsink side of the controller Because NTC ther mistors are non linear devices the conversion or the read value into a temperature value requires interpolation and a look up table Figure 34 on page 64 shows this correlation Sample conversion software code is available from Roboteg upon request The values are unsigned Hexadecimal numbers ranging from 0 to 255 The lowest read value represents the highest temperature Syntax m or M Reply nn mm Where nn thermistor 1 read value mm thermistor 2 read value Notes The hexadecimal format is intended to be deciphered by a microcontroller When exercis ing the controller manually you m
138. modes e Fully programmable through connection to a PC e Non volatile storage of user configurable settings e Simple operation e Software upgradable with new features Multiple Command Modes e Radio Control Pulse Width input e Serial port RS 232 input e 0 5V Analog Command input Multiple Advanced Motor Control Modes e Independent operation on each channel e Mixed control sum and difference for tank like steering e Open Loop or Closed Loop Speed mode e Position control mode for building high power position servos e Modes selectable independently for each channel Automatic Joystick Command Corrections e Joystick min max and center calibration e Selectable deadband width e Selectable exponentiation factors for each joystick e 3rd R C channel input for accessory output activation disabled when encoder mod ule present Special Function Inputs Outputs e 2 Analog inputs Used as e Tachometer inputs for closed loop speed control e Potentiometer input for position servo mode e Motor temperature sensor inputs e External voltage sensors AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Technical features e User defined purpose RS232 mode only 2 Extra analog inputs Used as e Potentiometer input for position while in analog command mode e User defined purpose RS232 mode only One Switch input configurable as e Emergency stop command e Reversing commands when running v
139. n Analog Mode In Analog mode Analog Inputs 1 and 2 are already used to supply the command Therefore Analog inputs 3 and 4 are used for feedback Feedback Potentiometer wiring in RC or RS232 Mode In RC or RS232 mode feedback is connected to Analog Inputs 1 and 2 Connecting the potentiometer to the controller is as simple as shown in the diagram on below Note that this wiring must not be used if the controller is configured in Analog mode but is switched in RS232 after power up using the method discussed in Entering RS232 from R C or Analog mode on page 126 Instead used the wiring for Analog mode discussed in the next section AX1500 Motor Controller User s Manual Closed Loop Position Mode lRoboteQ O 14 5V 2k 10k 2k 10k O 5 Ground Feedback 1 _ 11 Anat Feedback 2 O 10 Ana2 O 12 Ana3 O 8 Ana4 FIGURE 49 Pot wiring for RS232 or RC Command and Analog Feedback Feedback Potentiometer wiring in Analog Mode When the controller is configured in Analog mode the analog inputs 1 and 2 are used for commands while the analog inputs 3 and 4 are used for feedback Analog inputs 3 and 4 have different characteristics than inputs 1 and 2 and so require a lower resistance poten tiometer in order to guarantee accuracy Roborun will detect the new hardware revision and display Rev B on the screen O 14 5V 2k 2k 10k 2k 10k O 5 Ground C d1 enmon 11 Anal Command 2 O 10
140. n Battery Current and Motor current is given in the formula below Motor Current Battery Current PWM ratio Example If the controller reports 10A of battery current while at 10 PWM the current in the motor is 10 0 1 100A AX1500 Motor Controller User s Manual General Operation RoboteQ FIGURE 17 Current flow during operation FIGURE 18 Instant and average current waveforms The relation between Battery Current and Motor current is given in the formula below Motor Current Battery Current PWM Ratio Example If the controller reports 10A of battery current while at 10 PWM the current in the motor is 10 0 1 100A Important Warning Do not connect a motor that is rated at a higher current than the controller While the battery current will never exceed the preset Amps limit that limit may be reached at a PWM cycle lower than 100 resulting in a higher and potentially unsafe level through the motor and the controller Regeneration Current Limiting The AX1500 s current sensor is capable of measuring current in the reverse flow regener ation Using this capability the controller will automatically relax the braking effect of the power output stage to keep the regeneration current within safe values Because of the controller s high current handling capabilities this protection mechanism activates only when abrupt deceleration are applied to high inertia ultra
141. n configured in the Analog Input mode this will cause the motors to be at the Off state if the controller is powered with nothing connected to its analog inputs Important Notice The controller will not activate after power up or reset until the analog inputs are at 2 5V Selecting the Potentiometer Value The potentiometer can be of almost any value Undesirable effects occur however if the value is too low or too high If the value is low an unnecessarily high and potentially damaging current will flow through the potentiometer The amount of current is computed as the voltage divided by the poten tiometer s resistance at its two extremes For a 1K potentiometer the current is I U R 5V 1000 Ohms 0 005A 5mA For all practical purposes a 1K potentiometer is a good minimal value If the value of the potentiometer is high then the two 47K resistors built into the controller will distort the reading The effect is minimal on a 10K potentiometer but is significant on a 100K or higher potentiometer Figure 77 shows how the output voltage varies at the vari ous potentiometer positions for three typical potentiometer values Note that the effect is an exponentiation that will cause the motors to start moving slowly and accelerate faster as the potentiometer reaches either end This curve is actually preferable for most applications It can be corrected or amplified by changing the controller s exponentiation parameters
142. n feedback input 54 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Connecting devices to Output C TABLE 8 DB15 connector pin assignment Pin Input or Signal depending Number Output on Mode Description RC RS232 Ana in 2 Channel 2 speed or position feedback input 10 Analog in Analog Command 2 Analog command for channel 2 11 Analog in RC RS232 Ana in 1 Channel 1 speed or position feedback input Analog Command 1 Analog command for channel 1 12 Analog in RC Unused RS232 Ana in 3 Analog input 3 Ana Ana in 3 Channel 1 speed or position feedback input 14 Power Out 5V 5V Power Output 100mA max 15 Input Input EStop Inv Emergency Stop or Invert Switch input These connections should only be done in RS232 mode or R C mode with radio pow ered from the controller Connecting devices to Output C Output C is a buffered Open Drain MOSFET output capable of driving over 2A at up to 24V The diagrams on Figure 23 show how to connect a light or a relay to this output Relay Valve Motor Solenoid or other Inductive Load Lights LEDs or any other non inductive load 5 to 24V Internal DC Output C 1 9 Transistor Output C 1 9 nee ransistor Ground 5 Ground 5 FIGURE 23 Connecting inductive and resistive loads to Output C This output can be turned On and Off using the Channel 3 Joystick when in the R C mode See
143. n this side of the controller If the controller must be located at a longer distance the effects of the wire inductance may be reduced by using one or more of the following techniques e Twisting the power and ground wires over the full length of the wires e Use the vehicle s metallic chassis for ground and run the positive wire along the sur face e Adda capacitor 5 000uF or higher near the controller Electrical Noise Reduction Techniques As discussed in the above section the AX1500 uses fast switching technology to control the amount of power applied to the motors While the controller incorporates several cir cuits to keep electrical noise to a minimum additional techniques can be used to keep the noise low when installing the AX1500 in an application Below is a list of techniques you can try to keep noise emission low e Keep wires as short as possible e Loop wires through ferrite cores e Add snubber R C circuit at motor terminals e Keep controller wires and battery enclosed in metallic body Power Regeneration Considerations When a motor is spinning faster than it would normally at the applied voltage such as when moving downhill or decelerating the motor acts like a generator In such cases the current will flow in the opposite direction back to the power source It is therefore essential that the AX1500 be connected to rechargeable batteries If a power supply is used instead the current will attempt to flow
144. nals that are available on the controller s connector may be used to power the R C radio The wire loop is used to bring the controller s power to the the radio as well as for powering the optocoupler stage Figure 66 below shows the con nector wiring necessary to do this Figure 67 shows the equivalent electrical diagram 104 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Powering the Radio from the controller Channel 3 3 Channel 1 Command Pulses 4 Channel 2 Command Pulses 6 Radio battery Ground Ts Radio battery 8 Channel 3 Command Pulses Wire loop bringing power from controller to RC radio FIGURE 66 Wiring for powering R C radio from controller 14 Controller Power R C Radio MCU R C Channel 3 8 Controller Ground FIGURE 67 R C Radio powered by controller electrical diagram Important Warning Do not connect a battery to the radio when in this mode The battery voltage will flow directly into the controller and cause permanent damage if its voltage is higher than 5 5V This mode of operation is the most convenient and is the one wired in the R C cable deliv ered with the controller AX1500 Motor Controller User s Manual 105 R C Operation RoboteQ Connecting to a Separately Powered Radio This wiring option must be used when the controller is used with a RC receiver that is powered by its own separate batt
145. nction you will need to disable the PCM radio watchdog R C Transmitter Receiver Quality Considerations As discussed earlier in this chapter the AX1500 will capture the R C s command pulses with great accuracy It will therefore be able to take advantage of the more precise joy sticks and timings that can be found in higher quality R C radio if such added precision is desired in the application Another important consideration is the R C receiver s ability to operate in an electrically noisy environment the AX1500 switches high current at very high frequencies Such tran sients along long battery and motor wires will generate radio frequency noise that may interfere with the R C radio signal The effects may include reduced remote control range and or induced errors in the command pulse resulting in jerky motor operation A higher quality PCM R C transmitter radio is recommended for all professional applica tions as these are more immune to noise and interference While a more noise immune radio system is always desirable it is also recommended to layout the wiring the controller radio and antenna so that as little as possible electrical noise is generated Section Electrical Noise Reduction Techniques on page 35 provides a few suggestions for reducing the amount of electrical noise generated in your robot Joystick Deadband Programming In order to avoid undesired motor activity while the joysticks are centered the AX
146. nd Motors to the Controller This section describes the AX1500 Controller s connections to power sources and motors Important Warning Please follow the instructions in this section very carefully Any problem due to wir ing errors may have very serious consequences and will not be covered by the prod uct s warranty Power Connections The AX1500 has three Ground two Vmot terminals and a Power Control terminal The power terminals are located at the back end of the controller The various power terminals are identified by markings on the PCB The power connections to the batteries and motors are shown in the figure below AX1500 Motor Controller User s Manual 27 Connecting Power and Motors to the Controller RoboteQ Note Both VMot terminals are Ee connected to each other in gt m m the board and must be a wired to the same voltage ES Ctrl M1 M1 VMot i VMot M2 M2 3 x Gnd Motor 2 Motor 1 FIGURE 7 Controller Rear View and Power Connector Tabs Controller Power The AX1500 uses a flexible power supply scheme that is best described in Figure 8 In this diagram it can be seen that the power for the Controller s microcomputer is separate from this of the motor drivers The microcomputer circuit is connected to a DC DC converter which takes power from either the Power Control wire or the VMot input The diode circuit is designed to automat
147. nged the controller will wait until the new status has remained stable for 0 5s before acknowl edging it and inverting the commands This delay is to prevent switch activation triggered by hits and bounces which may cause the controller to erroneously invert the commands AX1500 Motor Controller User s Manual 49 General Operation lRoboteQ Special Use of Accessory Digital Inputs The AX1500 includes two general purpose digital inputs identified as Input E and Input F When an Encoder Module is installed input E is disabled The location of these inputs on the DB15 connector can be found in the section I O List and Pin Assignment on page 54 while the electrical signal needed to activate them is shown on Connecting Switches or Devices to Input F on page 56 By default these inputs are ignored by the controller However the AX1500 may be config ured to cause either of the following actions e Activate the buffered Output C e Turn Off On the power MOSFET transistors These alternate modes can only be selected using the Roborun Utility see Control Set tings on page 165 Each of these modes is detailed below Using the Inputs to Activate the Buffered Output When this setting is selected the buffered Output C will be On when the Input line is pulled to Ground OV The Output will be Off when the Input is pulled high This function makes it possible to drive solenoids or other accessories up to 2A at 24
148. ns a 4 bit number identifying the encoder module hardware version and the status of two on board jumpers For Roboteq use only Switch Status Address 85 Returns a 4 bit number 4 least significant bits of the byte each representing the state of one of the limit switches when installed The W command described at Read Encoder Limit Switch Status on page 147 is a preferred method for reading this information Speed or Distance 1 or 2 Address 86 Channel 1 87 Channel 2 150 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ Register Description These two registers contain either the measured speed or the measured distance Whether speed or distance information is returned depends on the settings contained in the Mode register described at This information is returned using the p query see Query Analog Inputs on page 131 Counter Read Write Mailbox Address 88 Most Significant Byte 89 8A 8B Least Significant Byte Since the counters are 32 bits wide and accesses are 8 bit wide it would normally take four separate accesses to fully read or write any of the counters If the motors are running and the counter is changing in between these accesses inaccurate data will be either read or written Therefore a two step process is implemented for accessing the encoder s counters for loading a new value in the counter the value must first be loaded in the mail box It is
149. ntroller you should use the Roborun utility described on page 121 Use and benefits of RS232 The serial port allows the AX1500 to be connected to microcomputers or wireless modems This connection can be used to both send commands and read various status information in real time from the controller The serial mode enables the design of autono mous robots or more sophisticated remote controlled robots than is possible using the R C mode RS232 commands are very precise and securely acknowledged by the controller They are also the method by which the controller s features can be accessed and operated to their fullest extent When connecting the controller to a PC the serial mode makes it easy to perform simple diagnostics and tests including e Sending precise commands to the motors e Reading the current consumption values and other parameters e Obtaining the controller s software revision and date e Reading inputs and activating outputs e Setting the programmable parameters with a user friendly graphical interface e Updating the controller s software AX1500 Motor Controller User s Manual 121 Serial RS 232 Controls and Operation RoboteQ Connector I O Pin Assignment RS232 Mode FIGURE 1 Pin locations on the controller s 15 pin connector When used in the RS232 mode the pins on the controller s DB15 connector are mapped as described in the table below TABLE 20 DB15 Connector pin assignment in R
150. of rotation If the motor turns in the direction in which the sensor was moved the polarity is correct The sensor axle may be tighten to the motor assembly 86 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Encoder Error Detection and Protection 10 If the motor turns in the direction away from the sensor then the polarity is reversed The wire polarity on the motors should be exchanged If using a potenti ometer as sensor the GND and 5V wires on the potentiometer may be swapped instead If using an Optical Encoder ChA and ChB outputs can be swapped 11 Move the sensor back to the center point to stop the motor Cut the power if con trol is lost 12 If the polarity was wrong invert it and repeat steps 8 to 11 13 Tighten the sensor Important Safety Warning Never apply a command that is lower than the sensor s minimum output value or higher than the sensor s maximum output value as the motor would turn forever try ing to reach a position it cannot For example if the max position of a potentiometer is 4 5V which is a position value of 114 a destination command of 115 cannot be reached and the motor will not stop Encoder Error Detection and Protection The AX1500 contains an Encoder detection and protection mechanism that will cause the controller to halt if no motion is detected on either Encoder while a power level of 25 or higher is applied to the motor If such an
151. oltage the proper external components must be added to the controller See Connecting External Ther mistor to Analog Inputs on page 61 and Using the Analog Inputs to Monitor External Voltages on page 62 The Enc field contains the speed or position depending on the selected operating mode measured by the Optical Encoder if enabled The Temp field displays the temperature at the Output Power Transistors for each channel The Bat Volt field displays the main battery s voltage voltage applied at the Vmot tabs The Ctrler Volt field displays the controller s internal regulated 12V voltage 4 Real Time Strip Chart Recorder This chart will plot the actual Amps consumption and other parameters as measured from the controller When active the chart will show measurement during the last five seconds Traces for most parameters can be displayed or hidden by clicking on the checkboxes found next to their numeric fields 5 Transmit and Receive Data These two fields show the data being exchanged between the PC and the controller While these fields are updated too fast to be read by a person they can be used to verify that a dialog is indeed taking place between the two units After the Start button is pressed the Tx field will show a continuous string of commands and queries sent to the controller The Rx field will display the responses sent by the controller If this field remains blank or is not changing even though the Tx f
152. ommand Control Curves The AX1500 can also be set to translate the joystick motor commands so that the motors respond differently depending on whether the joystick is near the center or near the extremes Five different exponential or logarithmic translation curves may be applied Since this feature applies to the R C Analog and RS232 modes it is described in detail in Command Control Curves on page 46 in the General Operation section of this manual AX1500 Motor Controller User s Manual 109 R C Operation RoboteQ Left Right Tuning Adjustment When operating in mixed mode with one motor on each side of the robot it may happen that one motor is spinning faster than the other one at identically applied power causing the vehicle to pull to the left or to the right To compensate for this the AX1500 can be made to give one side up to 10 more power than the other at the same settings This capability is described in detail in Left Right Tuning Adjustment on page 47 in the General Operation section of this manual Joystick Calibration This feature allows you to program the precise minimum maximum and center joystick positions of your R C transmitter into the controller s memory This feature will allow you to use the full travel of your joystick i e minimum 100 reverse maximum 100 for ward It also ensures that the joystick s center position does indeed correspond to a 0 motor command value
153. on Read the value of the Encoder counter s The number is a signed 32 bit number that may range from 2 147 836 648 to 2 147 836 647 The value is output in Hexadecimal format of value 80000000 to 7FFFFFFF respectively To speed up communication only the signifi cant digits are sent in response to a counter query For example if the counter contains the value 5 which is the same number in decimal and hex the response to the query will be 5 and not 00000005 The formatting algorithm takes into account the number s sign Details on the data format are given in section Counters values can be read as Absolute or Relative An Absolute counter read will return the full counter value after every read query In a Relative counter read the counter value is immediately cleared immediately after being read so that the next read query returns the new number of counts since the last time the counter was read Additionally in a few of the query modes the Encoder module returns the sum for both counters This is useful for measuring the average travelled distance by the right and left wheels of a robotic vehicle Syntax q or Qn Where n 0 Encoder 1 Absolute 1 Encoder 2 Absolute 2 Sum of Encoders 1 and 2 Absolute 4 Encoder 1 Relative 5 Encoder 2 Relative 6 Sum of Encoders 1 and 2 Relative Reply nnnoannnn Where nnnnnnnn counter value using 1 to 8 Hex digits See Counter Read Data Format on page 153 for format descrip
154. onditions and adjust actions accordingly Multiple options are available for each of the above listed functions which can be combined to produce practically any desired mobile robot configuration Input Command Modes The controller will accept commands from one of the following sources e R C radio e Serial data RS232 e Analog signal 0 to 5V A detailed discussion on each of these modes and the available commands is provided in the following dedicated chapters R C Operation on page 101 Serial RS 232 Controls and Operation on page 121 and Analog Control and Operation on page 113 The controller s factory default mode is R C radio The mode can be changed using any of the methods described in Loading Changing Controller Parameters on page 164 AX1500 Motor Controller User s Manual 39 General Operation lRoboteQ Selecting the Motor Control Modes For each motor the AX1500 supports multiple motion control modes The controller s fac tory default mode is Open Loop Speed control for each motor The mode can be changed using any of the methods described in Loading Changing Controller Parameters on page 164 Open Loop Separate Speed Control In this mode the controller delivers an amount of power proportional to the command information The actual motor speed is not measured Therefore the motors will slow down if there is a change in load as when encountering an obstacle and change in sl
155. onnect a joystick to the PC and enable it by clicking in the Joystick check box in the PC utility If the box is grayed out the joystick is not properly installed in the PC Click on the Config Joystick button to open a configuration screen and the joystick control panel Joystick movement should automatically translate into Channel 1 and Channel 2 command values and make the sliders move These commands are also sent to the controller In the Config Joystick panel the Joystick may be configured so that the X Y channels are swapped and the direction for each axis reversed It is strongly recommended that an USB rather than Analog joystick be used A joystick test program name Joytest is automatically installed in the Start menu when installing the Roborun utility This program may be used to further verify that the joystick is properly installed in the PC and is fully operational Using the Console The console screen allows you to communicate with the controller using raw ASCII data This function is very useful for troubleshooting when normal communication with Roborun 174 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Using the Console cannot be established e g Controller not found no response to command changes communication errors etc The Roborun utility will let you exercise and monitor the motors sensors and actuators using a computer This feature is particu
156. ope This mode is adequate for most applications where the operator maintains a visual contact with the robot In the separate speed control mode channel 1 commands affect only motor 1 while chan nel 2 commands affect only motor 2 This is illustrated in Figure 13 below Motors Speed Mot1 Mot2 A Vhs Fase Slow Commands ai E O P A ty speed Controller Motor 2 E oe Stop Stop n Vos Af 50 100 wy Slow Fast FIGURE 13 Examples of effect of commands to motors in separate mode Open Loop Mixed Speed Control This mode has the same open loop characteristics as the previously described mode How ever the two commands are now mixed to create tank like steering when one motor is used on each side of the robot Channel 1 is used for moving the robot in the forward or reverse direction Channel 2 is used for steering and will change the balance of power on each side to cause the robot to turn Figure 14 below illustrates how the mixed mode works AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Selecting the Motor Control Modes Commands Motors Speed Ch1 Ch2 Mot1 Mot2 ha 100 0 Motor 1 speed Controller Motor 2 speed FIGURE 14 Effect of commands to motors examples in mixed mode Closed Loop Speed Control In this mode illustrated in Figure 16 an analog tachometer or an optical encoder is used to measure the a
157. or 71 Reply nn mm oo Where nn Input E status mm Input F status oo Estop Invert Switch Input status Examples l Read Input status query 01 Controller replies Input E is On 00 Input F is Off 01 Emergency stop switch is high not triggered Note the Input E value is not meaningful if the encoder module is present and should be discarded Reset Controller Description This command allows the controller to be reset in the same manner as if the reset button were pressed This command should be used in exceptional conditions only or after chang ing the controller s parameters in Flash memory so that they can take effect Syntax rrrrrr 132 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Accessing amp Changing Configuration Parameter in Flash Reply None Controller will reset and display prompt message Accessing amp Changing Configuration Parameter in Flash It is possible to use RS232 commands to examine and change the controller s parameters stored in Flash These commands will appear cryptic and difficult to use for manual param eter setting It is recommended to use the Graphical configuration utility described in Using the Roborun Configuration Utility on page 161 Note that many parameters will not take effect until the controller is reset or a special command is sent The complete list of parameters accessible using these commands is listed in Automatic Swit
158. ording to the configuration contained in Flash Values are in Hexadecimal Example 00000101 Hex 05 TABLE 24 Operating Modes Register Definition Bit Function 7to3 Not Used 2 0 Open Loop 1 Closed Loop when in Speed Mode 1 0 Speed Mode 1 Position Mode 0 0 Analog Feedback 1 Encoder Feedback Read Change PID Values Address A82 P1 83 11 A84 D1 A85 P2 142 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Reading amp Changing Operating Parameters at Runtime A86 12 A487 D2 Access Read Write Effective Instantly The Proportional Integral and Derivative gain for each channel can be read and changed on the fly This function also provides a mean for setting different PID values for each channel Actual Gain value is the value contained in the register divided by 8 Changes take effect at the controller s next 16ms iteration loop After reset these bits get initialized according to the configuration contained in Flash PWM Frequency Register Address 88 Access Read Write Effective Instantly The controller s default 16kHz PWM Frequency can be changed to a higher value in fine increments This feature may be used to reduce the interference in case the controller s PWM frequency harmonics are too close to the radio receiver s frequency The value can be changed at any time and takes effect immediately The frequency is 15 625 Hz 2
159. ply a higher level of power for a given measured error thus making the motor react more quickly to changes in commands and or motor load AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ PID tuning in Speed Mode The Differential component of the algorithm computes the changes to the error from one 16 ms time period to the next This change will be a relatively large number every time an abrupt change occurs on the desired speed value or the measured speed value The value of that change is then multiplied by a user selectable Differential Gain and added to the out put The effect of this part of the algorithm is to give a boost of extra power when starting the motor due to changes to the desired speed value The differential component will also greatly help dampen any overshoot and oscillation The Integral component of the algorithm perform a sum of the error over time This compo nent helps the controller reach and maintain the exact desired speed when the error is reaching zero i e measured speed is near to or at the desired value Proportional Gain Tachometer or Optical Encoder Differential Gain FIGURE 58 PID algorithm used in Speed mode PID tuning in Speed Mode As discussed above three parameters Proportional Gain Integral Gain and Differential Gain can be adjusted to tune the Closed Loop Speed control algorithm The ultimate goal in a well tuned PID is a motor tha
160. portant that the tachometer and its wiring be extremely robust If the tachometer reports an erroneous voltage or no voltage at all the controller will con sider that the motor has not reached the desired speed value and will gradually increase the applied power to the motor to 100 with no way of stopping it until power is cut off or the Emergency Stop is activated Control Loop Description The AX1500 performs the Closed Loop Speed mode using a full featured Proportional Inte gral and Differential PID algorithm This technique has a long history of usage in control systems and works on performing adjustments to the Power Output based on the differ ence measured between the desired speed set by the user and the actual position cap tured by the tachometer Figure 58 shows a representation of the PID algorithm Every 16 milliseconds the control ler measures the actual motor speed and subtracts it from the desired position to compute the speed error The resulting error value is then multiplied by a user selectable Proportional Gain The resulting value becomes one of the components used to command the motor The effect of this part of the algorithm is to apply power to the motor that is proportional with the dif ference between the current and desired speed when far apart high power is applied with the power being gradually reduced as the motor moves to the desired speed A higher Proportional Gain will cause the algorithm to ap
161. put 1 is used for com mands while the analog input 4 is used for feedback O 14 5V 2k 10k O 5 Ground Cc d a 11 Anal O 10 Ana2 Feedback 12 Ana3 O 8 Ana4 FIGURE 52 Pot wiring on Single Channel controllers SC version and Analog Command Analog inputs 3 and 4 have different characteristics than inputs 1 and 2 and so require a lower resistance potentiometer in order to guarantee accuracy Important Notice AX1500 Motor Controller User s Manual 85 Closed Loop Position Mode lRoboteQ This wiring is also the one to use when the controller is in Analog mode but switched to RS232 after reset using the method discussed in Entering RS232 from R C or Analog mode on page 126 Using Optical Encoders in Position Mode The AX2550 and AX1500 may be equipped with an optional Optical Encoder Module Opti cal Encoders require special handling See Figure 7 Installing Connecting and Using the Encoder Module on page 67 for a detailed discussion Sensor and Motor Polarity The sensor polarity i e which rotation end produces 0 or 5V is related to the motor s polarity i e which direction the motor turns when power is applied to it In the Position mode the controller compares the actual position as measured by the sen sor to the desired position If the motor is not at that position the controller will apply power to the motor so that it turns towards that destination until reached
162. r a fourtime multiplication of resolution can be achieved by counting the rising and falling edges of each channel A and B For example an encoder that produces 250 Pulses per Revolution PPR can generate 1 000 Counts per Revolution CPR after quadrature AX1500 Motor Controller User s Manual 67 Installing Connecting and Using the Encoder Mod RoboteQ acam 1 LJ LJ LJ LIL 1 Pulse 4 Transitions B Channel 4 Counts l Quadrature EERO AEE E Oe ee oe Signal ee ee re Count Up Count Down FIGURE 35 Quadrature encoder output waveform The figure below shows the typical construction of a quadrature encoder As the disk rotates in front of the stationary mask it shutters light from the LED The light that passes through the mask is received by the photo detectors Two photo detectors are placed side by side at so that the light making it through the mask hits one detector after the other to produces the 900 phased pulses 8 LED light source ee Rotating ae yd encoder disk Stationary mask Photodetector SF Q FIGURE 36 Typical quadrature encoder construction Unlike absolute encoders incremental encoders have no retention of absolute position upon power loss When used in positioning applications the controller must move the motor until a limit switch is reached This position is then used as the zero reference for all subsequent moves Recommended Encoder Types The module ma
163. r AX1500 controller design Changed Power Connection section April 15 2003 1 1 Added analog mode section Added position mode section Added RCRC monitoring feature Updated Roborun utility section Modified RS232 watchdog March 15 2003 1 0 Initial Release The information contained in this manual is believed to be accurate and reliable However it may contain errors that were not noticed at time of publication User s are expected to perform their own product validation and not rely solely on data contained in this manual AX1500 Motor Controller User s Manual lRoboteQ AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ Revision History 3 SECTION 1 Important Safety Warnings 13 This product is intended for use with rechargeable batteries 13 Avoid Shorts when Mounting Board against Chassis 13 Do not Connect to a RC Radio with a Battery Attached 13 Beware of Motor Runaway in Improperly Closed Loop 13 SECTION 2 AX1500 Quick Start 15 What you will need 15 Locating the Connectors 15 Connecting to the Batteries and Motors 17 Connecting to the 15 pin Connector 18 Connecting the R C Radio 19 Powering On the Controller 20 Default Controller Configuration 20 Connecting the controller to your PC using Roborun 21 Obtaining the Controller s Software Revision Number 22 Exploring further 22 SECTION 3 AX1500 Motor Controller Overview 23 Product Description 23 Technical featur
164. r and that it may be temporarily be different than the temperature measured outside the case 300 es 250 4 200 Ned 150 Se 100 Reported Analog Value Po 50 hare Mann PAo e PS SH PHP PP SH SEANA OOY Temperature in Degrees C FIGURE 34 Analog reading by controller vs internal heat sink temperature Temperature Conversion C Source Code The code below can be used to convert the analog reading into temperature It is provided for reference only Interpolation table is for the internal thermistors int ValToHSTemp int AnaValue Interpolation table Analog readings at 40 to 150 oC in 50 intervals int TempTable 39 248 246 243 240 235 230 224 217 208 199 188 177 165 153 140 128 116 104 93 83 74 65 58 51 45 40 35 31 27 24 21 19 17 15 13 12 11 9 8 int LoTemp HiTemp lobound hibound temp i i 38 while TempTable i lt AnaValue amp amp i gt 0 isng if i lt 0 i 0 if i 38 return 150 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Internal Heatsink Temperature Sensors else LoTemp i 5 40 HiTemp LoTemp 5 lobound TempTable i hibound TempTable i 1 temp LoTemp 5 AnaValue lobound 100 hibound lobound 100 ret
165. r s Manual 113 Analog Control and Operation RoboteQ Connector I O Pin Assignment Analog Mode When used in the Analog mode the pins on the controller s DB15 connector are mapped as described in the table below TABLE 18 DB15 Connector pin assignment in Analog mode Pin Input or Number Signal Output Description 1 Output C Output 2A Accessory Output C same as pin 9 2 Data Out Output RS232 data output to the PC for data logging 3 Data In Input unused 4 Input F Input See Special Use of Accessory Digital Inputs on page 50 5 Ground Out Power Output Controller ground 6 Unused Unused 7 Unused Unused 8 Input E Analn4 Input Channel 2 position feedback input servo mode 9 Output C Output 2A Accessory Output C same as pin 1 0 Channel 2 In Analog in Channel 2 Command Input 1 Channel 1 In Analog in Channel 1 Command Input 2 Analog Input 3 Input Channel 1 position feedback input servo mode 3 Ground Out Power Controller ground 4 5V Out Power Output 5V Power Output 100mA max 5 Switch Input Input Emergency Stop or Invert Switch input 114 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Connecting to a Voltage Source Connecting to a Voltage Source The analog inputs expect a DC voltage of 0 to 5V which can be sourced by any custom cir cuitry potentiometer Digital to Analog converter The
166. r to the motors accordingly The AX1500 can also be configured to operate as a precision high torque servo con troller When connected to a potentiometer coupled to the motor assembly the controller will command the motor to rotate up to a desired angular position Depending on the DC motor s power and gear ratio the AX1500 can be used to move or rotate steering columns or other physical objects with very high torque The AX1500 is fitted with many safety features ensuring a secure poweron start automatic stop in case of command loss over current protection on both channels and overheat protection AX1500 Motor Controller User s Manual 23 AX1500 Motor Controller Overview lRoboteQ The motors are driven using high efficiency Power MOSFET transistors controlled using Pulse Width Modulation PWM at 16kHz The AX1500 power stages can operate from 12 to 40VDC and can sustain up to 30A of controlled current delivering up to 1200W approx imately 1 5 HP of useful power to each motor The many programmable options of the AX1500 are easily configured using the supplied PC utility Once programmed the configuration data are stored in the controller s non vola tile memory eliminating the need for cumbersome and unreliable jumpers Optical Encoders allow precise motor speed and position measurement and enable advance robotic applications Technical features Fully Digital Microcontroller based Design e Multiple operating
167. r wiring can be found at Connecting Power and Motors to the Controller on page 27 The DB15 connector is used for all low voltage low current connections to the Radio Microcontroller sensors and accessories This section covers only the connections to sen sors and actuators For information on how to connect the R C radio or the RS232 port see R C Operation on page 101 and Serial RS 232 Controls and Operation on page 121 AX1500 Motor Controller User s Manual 51 Connecting Sensors and Actuators to Input Outputs RoboteQ 1 DC Motors 6 R C Radio Receiver microcomputer or 2 Optional sensors wireless modem Tachometers Closed loop Speed mode 7 Command RS 232 R C Pulse Potentiometers Servo mode P M ll Encoders when Module present iscellaneous I O Running 3 3 Motor Power supply wires 9 ae nverted or emergency stop 4 Power Control wire5 Controller FIGURE 21 Typical controller connections AX1500 s Inputs and Outputs In addition to the RS232 and R C channel communication lines the AX1500 includes sev eral inputs and outputs for various sensors and actuators Depending on the selected oper ating mode some of these I Os provide feedback and or safety information to the controller AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ AX1500 s Inputs and Outputs When the controller operates in modes that do not use these I O
168. ral Gain Differential Gain The Differential component of the algorithm computes the changes to the error from one 16 ms time period to the next This change will be a relatively large number every time an abrupt change occurs on the desired position value or the measured position value The value of that change is then multiplied by a user selectable Differential Gain and added to the output The effect of this part of the algorithm is to give a boost of extra power when starting the motor due to changes to the desired position value The differential component will also help dampen any overshoot and oscillation The Integral component of the algorithm performs a sum of the error over time In the posi tion mode this component helps the controller reach and maintain the exact desired posi tion when the error would otherwise be too small to energize the motor using the Proportional component alone Only a very small amount of Integral Gain is typically required in this mode PID tuning in Position Mode As discussed above three parameters Proportional Gain Integral Gain and Differential Gain can be adjusted to tune the position control algorithm The ultimate goal in a well tuned PID is a motor that reaches the desired position quickly without overshoot or oscilla tion Because many mechanical parameters such as motor power gear ratio load and inertia are difficult to model tuning the PID is essentially a manual process th
169. rently whether or not the joystick is near the center or near the extremes The controller can be configured to use one of 5 different curves independently set for each channel The factory default curve is a linear straight line meaning that after the joystick has moved passed the deadband point the motor s speed will change proportionally to the joy stick position Two exponential curves a weak and a strong are supported Using these curves and after the joystick has moved past the deadband the motor speed will first increase slowly increasing faster as the joystick moves near the extreme position Exponential curves allow better control at slow speed while maintaining the robot s ability to run at maximum speed Two logarithmic curves a weak and a strong are supported Using these curves and after the joystick has moved past the deadpoint the motor speed will increase rapidly and then increase less rapidly as the joystick moves near the extreme position The graph below shows the details of these curves and their effect on the output power as the joystick is moved from its center position to either extreme The graph is for one joy stick only The graph also shows the effect of the deadband setting AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Left Right Tuning Adjustment Forward Motor Output 100 Logarithmic Strong _ Logarithmic Weak
170. ressed Permanent Controller Identification Register TABLE 26 Controller Identification Register Definition Address A8A Access Read Only Effective Instantly This register may be used to query the Controller s model and some of its optional hard ware configurations Bit Model or Function AX500 AX1500 AX2500 AX3500 Unused Encoder Present Short Circuit Detection Present NI OO of BR ws nm gt oO Unused Current Amps Limit Registers Address A8B Channel 1 A8C Channel 2 Access Read Only Effective Instantly These registers can be polled to view what the Amps limit is at the current time This limit normally is the one that is preset by the user except when the controller is operating at high temperature in which case the allowable current drops as temperature rises See Temperature Based Current Limitation on page 42 To convert the register value in Amps divide the reading by 4 144 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ RS232 Encoder Command Set RS232 Encoder Command Set When present the Encoder module responds to a dedicated set of commands and que ries The serial port setting and basic command format is identical to this for all other functions of the controller as described in Serial RS 232 Controls and Operation on page 121 Read Encoder Counter Descripti
171. roller is configured in R C or Analog mode it will automatically and continu ously send a string of ASCII characters on the RS232 output This feature makes it possible to log the controller s internal parameters while it is used in the actual application The data may be captured using a PC connected via an RS232 cable FIGURE 1 Pin gsostietesermaodarorerdi e s POdinnataltedtiorthe actual robot Details on how to wire the DB15 connector is described on page 112 for the R C mode and on page 119 for the Analog mode This string is composed of a start character delimiter followed by two digit Hexadecimal numbers representing internal parameter values and ending with a Carriage Return charac ter The figure below shows the structure of this string FIGURE 85 ASCII string sent by the controller while in R C or Analog mode The hexadecimal values and format for each parameter is the same as the response to RS232 queries described in page 128 Characters are sent by the controller at the rate of one every 8ms A complete string is sent in 213ms Data Logging Cables The wring diagrams shown in the figures below describe an easy to assemble cable assembly for use to create insertion points where to connect the PC for debug and data 156 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Decimal to Hexadecimal Conversion Table logging purposes This cable has a 15 pin male connector and 3 15 pin
172. rom the time at which the peak was reset using the Clr Peak button Motor Amps is a calculated estimated value based on the batter amps and the current power level See Battery Cur rent vs Motor Current on page 43 The Power field displays the power level that is actually being applied to the motor This value is directly related to the motor command except during current limitation in which AX1500 Motor Controller User s Manual 171 Using the Roborun Configuration Utility lRoboteQ case the power level will be the one needed to keep the Amps within the limit Note that the display value is not signed and thus does not provide rotation direction information The Ana fields contain the analog input values that are measured and reported by the con troller When the controller is in the position mode with Analog Feedback the Ana1 and Ana2 fields will display the position sensed on the feedback potentiometer When in speed mode these fields display the measured speed by the tachometers When the controller is in Analog command mode the Ana 1 and Ana 2 show the vale of the command potentiom eter while the feedback is on Ana 3 and Ana 4 In all other modes this field will display the value at the analog input pin A small button next to this field will toggle the display caption and change the conversion algorithm from raw analog to volts or temperature Note that in order to measure and display the external temperature or v
173. rs are only effective on controllers equipped with Encoder Modules Bit 7 0 Definition See pages O to 63 16 default page 76 AX1500 Motor Controller User s Manual 139 lRoboteQ Serial RS 232 Controls and Operation Default Encoder Distance Divider Address AOE Access Read Write Effective After Reset or AFF This parameters is the Encoder s Distance Divider that is loaded after the controller is reset or powered on The Encoder Distance Divider can be changed at Runtime using separate commands see page 142 Parameter values are integer number from 0 to 7 This parame ter is only effective on controllers equipped with Encoder Modules Bit 7 0 Definition O to 63 16 default See pages page 76 Default PID Gains Address AOF Proportional Gain 410 Integral Gain A11 Derivative Gain Access Read Write Effective After Reset or 4FF These parameters are the Gains values that are loaded after the controller is reset or pow ered on These Gains apply to both channels Gains can be changed at Runtime and values can be different for each channel using separate commands see page 142 Gains values are integer number from 0 to 63 This number is divided by 8 internal so that each increment equals 0 125 Bit 7 0 Definition 0 to 63 16 default See pages page 89 and page 96 Joystick Min Max and Center Values Address 12 Joyst
174. rward la3F channel 1 50 reverse Notes The hexadecimal number must always contain two digits For example a5 will not be recognized and the controller will respond with a to indicate an error The proper com mand in this case should be a05 Set Accessory Output Description Turn on or off the digital output line on the 15 pin connector See AX1500 s Inputs and Out puts on page 52 for details on how to identify and wire these signals Syntax IM Where M c output C off C output C on Examples IC turn C output off Ic turn C output on AX1500 Motor Controller User s Manual 129 Serial RS 232 Controls and Operation lRoboteQ Query Power Applied to Motors Description This query will cause the controller to return the actual amount of power that is being applied to the motors at that time The number is a hexadecimal number ranging from 0 to 127 0 to 7F in Hexadecimal In most cases this value is directly related to the command value except in the conditions described in the notes below Syntax v or 2V Reply nn mm Where nn motor 1 applied power value mm motor 2 applied power value Notes The applied power value that is read back from the controller can be different than the com mand values for any of the following reasons current limitation is active motors operate at reduced speed after overheat detection or mixed mode is currently active No forward or reverse
175. s The controller will also send a W character every second to indicate to the microcom puter that such a time out condition has occurred The character does not need to be a specific command but any ASCII code including invis ible ones The RS232 watchdog is enabled or disabled depending on the value of the Input Com mand Mode parameter The RS232 watchdog is automatically enabled when entering the RS232 mode from the RC or from the Analog modes see Entering RS232 from R C or Analog mode on page 126 Controller Commands and Queries AX1500 commands and queries are composed of a series of 2 or 4 characters followed by the enter carriage return code The controller will send back echo every character it is receiving By checking that the returned character is the same as the one sent it is possible to verify that there has been no error in communication After a command has been received and properly executed the controller will send the character If a command has been received with errors or bad parameters the controller will send the character The table below lists the AX1500 RS232 commands and queries TABLE 21 Controller s basic Commands and Queries Command Type Description Yorrrrrr Command Reset Controller Ann Command Channel 1 forward command to value nn lann Command Channel 1 reverse command to value nn IBnn Comm
176. s and their effects Pot Position resulting in Pot Position resulting in Parameter Value Motor Power at 0 Motor Power at 100 0 0 2 5V 94 0 15V and 4 85V 1 0 to 2 4 2 44V to 2 56V 96 0 10V and 4 90V 2 0 to 4 7 2 38V to 2 62V 93 0 18V and 4 83V AX1500 Motor Controller User s Manual 117 Analog Control and Operation IRoboteQ TABLE 19 Analog deadband parameters and their effects Pot Position resulting in Pot Position resulting in Parameter Value Motor Power at 0 Motor Power at 100 3 default 0 to 71 2 32V to 2 68V 95 0 13V to 4 88V 4 0 to 9 4 2 27V to 2 74 93 0 18V and 4 83V 5 0 to 11 8 2 21V to 2 80V 95 0 13V to 4 88V 6 0 to 14 2 2 15V to 2 86V 94 0 15V and 4 85V 7 0 to 16 5 2 09V to 2 91V 96 0 10V and 4 90V Important Notice Some analog joysticks do not cause the potentiometer to reach either extreme This may cause the analog voltage range to be above OV and below 5V when the stick is moved to the extreme and therefore the controller will not be able to deliver full for ward or reverse power Power On Safety When powering on the controller power will not be applied to the motors until both the Channel 1 and Channel 2 potentiometers have been centered to their middle position 2 5V on each input This is to prevent the robot or vehicle from moving in case the joystick was in an active position at the momen
177. s input is No Action This input can also be configured to be used with an optional inverted sensor switch When activated this will cause the controls to be inverted so that the robot may be driven upside down When neither Emergency Stop or Inverted modes are selected this input becomes a gen eral purpose input like the other two described above This input is a high impedance input with a pull up resistor built into the controller There fore it will report an On state no emergency stop or not inverted if unconnected A sim ple switch as shown on Figure 26 is necessary to activate it Note that to trigger an Emergency Stop or to detect robot inversion this input must be pulled to ground Figure 26 show how to wire the switch to this input AX1500 Motor Controller User s Manual Connecting Sensors and Actuators to Input Outputs lRoboteQ AX2500 Internal Buffer and Resistor 5V 14 10kOhm Input EStop Inv 15 O Ground 5 FIGURE 26 Emergency Stop Invert switch wiring The status of the EStop Inv can be read at all times in the RS232 mode with the i com mand string The controller will respond with three sets of 2 digit numbers The status of the ES Inv Input is contained in the last set of numbers and may be 00 to indicate an Off state or 01 to indicate an On state Analog Inputs The controller has 4 Analog Inputs that can be used to connect position speed tempera ture volt
178. se of inertia they will act as generators and will turn the controller possibly in an unsafe state ALWAYS ground the Power Control wire to turn the controller Off and keep it Off Important Warning The controller includes large capacitors When connecting the Motor Power Cables a spark will be generated at the connection point This is a normal occurrence and should be expected Connecting to the 15 pin Connector The controller s I O are located on it s standard 15 pin D Sub Connector The functions of some pins varies depending on controller model and operating mode Pin assignment is found in the table below Signal Pin RC Mode RS232 Mode Analog Mode 2A Digital Output C same as pin 9 TxData RC Ch1 RxData Unused RC Ch 2 Digital Input F Ground Out Unused Unused CO NI OD oy AJ WwW N gt Digital Input E Not available when Encoder module is present and Analog Input 4 9 2A Digital Output C same as pin 1 Analog Input 2 Analog Input 1 Analog Input 3 Ground Out 5V Out 100mA max Emergency Stop or Invert Switch input oO BRB WwW NM gt o 18 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Connecting the R C Radio Connecting the R C Radio Connect the R C adapter cables to the controller on one side and to two or three channels on the R C receiver on the other side If present
179. sed Loop Position Mode lRoboteQ The diode polarity depends on the particular wiring and motor orientation used in the appli cation If the diode is mounted backwards the motor will not stop once the limit switch lever is pressed If this is the case reverse the diode polarity The diodes may be eliminated but then it will not be possible for the controller to move the motor once either of the limit switches has been triggered The main benefit of this technique is its total independence on the controller s electronics and its ability to work in practically all circumstances Its main limitation is that the switch and diode must be capable of handling the current that flows through the motor Note that the current will flow though the diode only for the short time needed for the motor to move away from the limit switches sw SWw2 ele ele Controller FIGURE 53 Safety limit switches interrupting power to motors Another method uses the AX1500 s Emergency Stop input to shut down the controller if any of the limit switches is tripped Figure 54 shows the wiring diagram used in this case Each of the limit switches is a Normally Open switch Two of these switches are typically required for each motor Additional switches may be added as needed for the second motor and or for a manual Emergency Stop Since very low current flows through the switches these can be small low cost switches The principal restriction of this technique
180. shows numbers for 0 to 127 decimal 00 to 7F hexadecimal The AX1500 s speed com mands are within this range Table 31 shows the conversion values for numbers between 128 and 255 unsigned and between 1 and 128 signed TABLE 30 0 to 127 signed or unsigned decimal to hexadecimal conversion table Dec Hex Dec Hex Dec Hex Dec Hex 0 00 32 20 64 40 96 60 1 01 33 21 65 41 97 61 2 02 34 22 66 42 98 62 3 03 35 23 67 43 99 63 4 04 36 24 68 44 100 64 AX1500 Motor Controller User s Manual 157 lRoboteQ TABLE 30 0 to 127 signed or unsigned decimal to hexadecimal conversion table Dec Hex Dec Hex Dec Hex Dec Hex 5 05 37 25 69 45 01 65 6 06 38 26 70 46 02 66 7 07 39 27 71 47 03 67 8 08 40 28 72 48 04 68 9 09 41 29 73 49 05 69 0 OA 42 2A 74 4A 06 6A 1 OB 43 2B 75 4B 07 6B 2 OC 44 2C 76 4C 08 6C 3 OD 45 2D 77 4D 09 6D 4 OE 46 2E 78 4E 10 6E 5 OF 47 2F 79 4F 11 6F 6 0 48 30 80 50 12 70 7 1 49 31 81 51 13 71 8 2 50 32 82 52 14 72 9 3 51 33 83 53 15 73 20 4 52 34 84 54 16 74 21 5 53 35 85 55 17 75 22 6 54 36 86 56 18 76 23 7 55 37 87 57 19 77 24 8 56 38 88 58 20 78 25 9 57 39 89 59 21 79 26 A 58 3A 90 5A 22 7A 27 B 59 3B 91 5B 23 7B 28 C 60 3C 92 5C 24 7C 29 D 61 3D 93 5D 25 7D 30 E 62 3E 94 5E 26 7E 31 F 63 3F 95 5F 27 7F TABLE 31 128 to 255 unsi
181. sion by placing a jumper on the PCB This step must be undertook only if you have the proper tooling and technical skills e Disconnect the controller from power e Insert a jumper as shown in Figure 12 Before paralleling the outputs e Place the load on channel 1 and verify that it is activated by commands on channel 1 e Then place the load on channel 2 and verify that is also activated by commands on channel 1 e Commands on channel 2 should have no effects on either output AX1500 Motor Controller User s Manual 33 Connecting Power and Motors to the Controller RoboteQ It will be safe to wire in parallel the controller s outputs only after you have verified that both outputs react identically to channel 1 commands KEREJ Heeee Jumper In for Single Channel FIGURE 12 AX1500 Jumper setting for Single Channel Operation Power Fuses For low Amperage applications below 30A per motor it is recommended that a fuse be inserted in series with the main battery circuit as shown in the Figure 9 on page 30 The fuse will be shared by the two output stages and therefore must be placed before the Y connection to the two power wires Fuse rating should be the sum of the expected cur rent on both channels Note that automotive fuses are generally slow will be of limited effectiveness in protecting the controller and may be omitted in high current application The fuse will mostly protect the wiring and
182. st be modified to add an RS232 output wire and connector that will be connected to the PC s communication port Figure 78 below shows the wiring diagram of the modified cable for connection to a PC or to a PDA respectively DB9 Female DB15 Male To PC To Controller 10 o O6 20 3 RX Data 2 0O RS232 Data Out O7 1 O Ana Ch2 30 O Os n AnaChi 40 O O9 120 5 GND 5sQj ____ gt GND 13 O O o 5V O 15 O O FIGURE 78 Modified Analog cable with RS232 output data logging for PC DB9 Male DB15 Male To PDA To AX2500 1 10 O RX Data 60 20 2 20 O RS232 Data Out O7 10 O gt Ana Ch 30 Q Os VO AnaChi O O9 120 GND 5 Q O GND 30 O 14 O C HV O 150 O FIGURE 79 Modified Analog cable with RS232 output data logging for PDA AX1500 Motor Controller User s Manual 119 Analog Control and Operation lRoboteQ 120 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Use and benefits of RS232 SECTION 13 Serial RS 232 Controls and Operation This section describes the communication settings and the commands accepted by the AX1500 in the RS232 mode of operations This information is useful if you plan to write your own controlling software on a PC or microcomputer These commands will also allow you to send commands manually using a terminal emulation program If you wish to use your PC simply to set parameters and or to exercise the co
183. t if it is used by a different device and program With the port open Roborun will try to establish communication with the controller If suc cessful this window will display the software revision the revision date and a set of digits identifying hardware revision of the board inside the controller 3 Parameter Selection and Setting and Special Functions AX1500 Motor Controller User s Manual 163 Using the Roborun Configuration Utility lRoboteQ This is the program s main frame and includes several types of tabs each of which has sev eral buttons menus and other User Interface objects These tabs and the functions they contain are described in detail in the following sections Navigate from one set of commands to another by clicking on the desired tab 4 File and Program Management Commands This frame contains a variety of buttons needed to load and save the parameters from and to the controller or disk This frame also contains the button needed to initiate a software update to the controller 5 View Controller Connector Pinout Clicking on this link will conveniently pop a window containing the Controller s connector pinout connector Pinout x RC Mode R8232 Mode Analog Mode Pin 1 Accessory Output C same as pin 9 Pin 2 R5232 Tx Data to PC Pin 3 RCChi Rx Data Unused Pin 4 RC Ch2 Accessory Input F Pin 5 Ground i Pin 6 GND Inpue Pin SV Input Pin 8 Unused Analog Input 4 Pin
184. t limitation circuit is activated See User Selected Current Limit Set tings on page 42 Note that this limits the current flowing from the battery The current flowing through the motor may be higher See Battery Current vs Motor Current on page 43 2 Left Right Adjust This slider will let you configure the controller so that it applies more power to the motors in one direction than in the other See Left Right Tuning Adjustment on page 47 3 Acceleration Setting This slider will let you select one of seven preset acceleration values The label on the right shows a numerical value which represents the amount of time the controller will take to 166 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Loading Changing Controller Parameters accelerate a motor from idle to maximum speed See Programmable Acceleration on page 45 Analog or R C Specific Settings Controls Power Settings Close Loop Encoder RC Out Run Console RC 16 Deadband None Max Joystick 1 Joystick 2 S Start 1100 Start 1100 C Center 400 Center 400 sia M Max 800 Max 800 M Joystick time in microseconds FIGURE 92 Power settings screen The screen shown in Figure 92 slightly changes in function of whether or not the Analog Input mode is selected If the Analog Input mode is selected on the main screen then this page is used to set the An
185. t reaches the desired speed quickly without overshoot or oscillation Because many mechanical parameters such as motor power gear ratio load and inertia are difficult to model tuning the PID is essentially a manual process that takes experimenta tion The Roborun PC utility makes this experimentation easy by providing one screen for chang ing the Proportional Integral and Differential gains and another screen for running and monitoring the motors First run the motor with the preset values Then experiment with different values until a satisfactory behavior is found AX1500 Motor Controller User s Manual 97 Closed Loop Speed Mode RoboteQ In Speed Mode the Integral component of the PID is the most important and must be set first The Proportional and Differential component will help improve the response time and loop stability In the case where the load moved by the motor is not fixed tune the PID with the mini mum expected load and tune it again with the maximum expected load Then try to find values that will work in both conditions If the disparity between minimal and maximal pos sible loads is large it may not be possible to find satisfactory tuning values Note that the AX1500 uses one set of Proportional Integral and Differential Gains for both motors and therefore assumes that similar motors mechanical assemblies and loads are present at each channel 98 AX1500 Motor Controller User s Manual Version 1 9b
186. t the controller was turned on Under Voltage Safety If the controller is powered through the Power Control input and the motor battery voltage drops below 5V the controller will be disabled until the analog commands are centered to the midpoint 2 5V on each input Data Logging in Analog Mode While in Analog Mode the AX1500 will continuously send a string of characters on the RS232 output line This string will contain two digits hexadecimal number representing the following operating parameters e Captured Analog Command 1 and 2 e Power Applied to Controller s output stage e Raw analog command values e Amps on channel 1 and 2 e Internal Heat Sink temperatures 1 and 2 e Main Battery voltage e Internal 12V voltage The entire string is repeated every 213 milliseconds with the latest internal parameter val ues This information can be logged using the Roborun Utility see Viewing and Logging 118 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 IRoboteQ Data Logging in Analog Mode Data in Analog and R C Modes on page 176 It may also be stored in a PDA that can be placed in the mobile robot The string and data format is described in Analog and R C Modes Data Logging String For mat on page 156 The serial port s output can be safely ignored if it is not required in the application To read the output string while operating the controller with an analog command the cable mu
187. tacts and the interposer chassis with an ohm meter prior to applying power 184 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Wire Dimensions Wire Dimensions The AX1500 uses screw terminals for the power connections to the batteries and motors These connectors are rated to support the controller s maximum specified current It is rec ommended that you use AWG12 wire for all power connections to ground batteries and motors The Power Control wire and its return Ground may be much thinner as they will never carry current in excess of a couple of milliamperes Weight Controller weight is 4 00z 120g AX1500 Motor Controller User s Manual 185 Mechanical Specifications lRoboteQ 186 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007
188. tching Off or cutting open the main power cables VMot terminals while the motors are spinning Damage to the controller may occur Overvoltage Protection The AX1500 includes a battery voltage monitoring circuit that will cause the output transis tors to be turned Off if the main battery voltage rises above 43V This protection is designed to prevent the voltage created by the motors during regenera tion to be amplified to unsafe levels by the switching circuit The controller will resume normal operation when the measured voltage drops below 43V Undervoltage Protection In order to ensure that the power MOSFET transistors are switched properly the AX1500 monitors the internal 12V power supply that is used by the MOSFET drivers If the internal voltage drops below 10V the controller s output stage is turned Off The rest of the control ler s electronics including the microcomputer will remain operational as long as the inter nal voltage is above 8V The internal voltage will be the output of the DC DC converter which will be a solid 12V as long as either of the main battery or backup voltage is higher than 12 5V If the main and backup voltage drop below 12 V the DC DC converter s output will be approximately 0 5V lower than the highest input Using the Controller with a Power Supply Using a transformer or a switching power supply is possible but requires special care as the current will want to flow back from
189. ters must be stored Cir Counter Value 9 in controller to take effect m Motors Command Tx Mott Stop j o Pa a E T S N ao FIGURE 94 Encoder setup and test screen on Roborun With this utility the following actions can be accomplished e Set and program the Encoder module s parameters in EEPROM e Activate the motors in each direction at variable speed e View the measured encoder counts e View the measured encoder speed e View the status of the Limit Switches The screen is composed of the following buttons and displays 1 Setting of the Encoder s threshold level 2 Setting of the Time Base for speed computation 3 Setting Divider for computing relative distance 4 Measure and display speed and relative distance 5 Measure and display counter values 6 Detect and display optional limit switch status 7 Start Stop communication with controller 8 Set motor speed and direction for testing Encoder Module Parameters Setting The Encoder module has four programmable parameters Two Time Bases one for each encoder a Divider for computing relative distance and the voltage threshold for discern ing a O or 1 level at the encoder s output In the case of the AX1500 the threshold is fixed at 2 5V and cannot be changed AX1500 Motor Controller User s Manual 169 Using the Roborun Configuration Utility lRoboteQ The Time Base parameter is used to compute the speed measured by the mo
190. tion RoboteQ is found on all R C transmitters and which is actually an offset correction the Left Right Adjustment is a true multiplication factor as shown in Figure 20 Forward Forward Motor Output 0 Motor Output 100 3 100 3 5 25 100 80 60 40 100 80 60 40 Command Input 20 20 40 40 60 60 80 5 25 i 100 3 Reverse 100 Forward 0 Reverse Motor Output FIGURE 20 Left Right adjustment curves The curves on the left show how a given forward direction command value will cause the motor to spin 3 or 5 25 slower than the same command value applied in the reverse direction The curves on the right show how the same command applied to the forward direction will case the motor to spin 3 to 5 25 faster than the same command applied in the reverse direction Note that since the motors cannot be made to spin faster than 100 the reverse direction is the one that is actually slowed down In applications where two motors are used in a mixed mode for steering the Left Right Adjustment parameter may be used to make the robot go straight in case of a natural ten dency to steer slightly to the left or to the right The Left Right adjustment parameter can be set from 5 25 to 5 25 in seven steps of 0 75 See Programmable Parameters L
191. tion Examples 00 Read Encoder 1 Absolute 05 Read Encoder 2 Relative Set Reset Encoder Counters and Destination Registers Description Set one or both counters to zero or a userdefined value The value is a signed 32 bit num ber that may range from 2 147 836 648 to 2 147 836 647 Hexadecimal format of value 80000000 to 7FFFFFFF respectively AX1500 Motor Controller User s Manual 145 RoboteQ While resetting is a single step command setting the counters to a non zero value requires two steps 1 load a 4 byte buffer 32 bit with the desired value 2 Transfer the buffer s content to the counter s Loading the buffer can be done using the commands described in Read Modify Encoder Module Registers and Parameters on page 148 The buffer will also be altered after a Counter Read command in which case it will contain the last read counter value Syntax lq or OQn Where n 0 Reset Encoder 1 counter 1 Reset Encoder 2 counter 2 Reset both Encoder counters 4 Set Encoder 1 counter with value in buffer Set Encoder 2 counter with value in buffer 6 Set both Encoder both counters with value in buffer ol 7 Set Encoder 1 destination register with value in buffer 8 Set Encoder 2 destination register with value in buffer Reply if command was properly received and executed if an error occurred Examples 102 Reset both counters 105 Load value contained in buffer into counter 2 7
192. tion Parameter flash They are then changed using RS232 commands Use the command following commands to Read Change the Operating Modes Syntax mm Read Parameters at location mm Amm DD Write Parameters DD in location DD mm and DD are Hexadecimal values The table below lists the available parameters TABLE 23 Runtime R W Parameters list Location Function R W A80 Channel 1 Operating Modes R W 81 Channel 2 Operating Modes R W 82 PID Proportional gain 1 R W 83 PID Proportional gain 2 R W 84 PID Integral gain 1 R W 85 PID Integral gain 2 R W AX1500 Motor Controller User s Manual 141 Serial RS 232 Controls and Operation RoboteQ TABLE 23 Runtime R W Parameters list Location Function R W A86 PID Differential gain 1 R W A87 PID Differential gain 2 R W A88 PWM frequency R W 89 Controller Status R Only 8A Controller Model R Only A8B Current Amps limit 1 R Only A8C Current Amps limit 2 R Only Important Notice Do not write in the locations marked as Read Only Doing so my cause Controller malfunction Operating Modes Registers Address A480 Channel 1 481 Channel 2 Access Read Write Effective Instantly Modifying the bits in the Operating Mode registers will change the controller s operating modes on the fly Changes take effect at the controller s next 16ms iteration loop After reset these bits get initialized acc
193. tion Sensor connection depending on operating mode Ana 1 Ana2 Ana 3 Ana 4 Operating Mode pin 11 pin 10 pin 12 pins RC or RS232 Dual Channel Position 1 Position 2 Unused Unused Analog Dual Channel Command 1 Command 2 Position 1 Position 2 RC or RS232 Single Channel Position Unused Unused Unused RC or RS232 Dual Channel Command Unused Position Unused See Closed Loop Position Mode on page 81 for complete details on Position Mode wir ing and operation Important Warning Beware that the wrong and polarity on the potentiometer will cause the motor to turn in the wrong direction and not stop The best method to figure out the right potentiometer is try one way and change the polarity if incorrect Note that while you are doing these tests the potentiometer must be loosely attached to the motor s axle so that it will not be forced and broken by the motor s uncontrolled rotation in case it was wired wrong Connecting Tachometer to Analog Inputs When operating in closed loop speed mode tachometers must be connected to the con troller to report the measured motor speed The tachometer can be a good quality brushed DC motor used as a generator The tachometer shaft must be directly tied to that of the motor with the least possible slack AX1500 Motor Controller User s Manual 59 Connecting Sensors and Actuators to Input Outputs RoboteQ Since the controller only accepts
194. to the lowest of the manual and temperature adjusted max values This capability ensures that the controller will be able to work safely with practically all motor types and will adjust itself automatically for the various load and environmental con ditions The time it takes for the heat sink s temperature to rise depends on the current output ambient temperature and available air flow natural or forced Note that the measured temperature is measured on the PCB near the Power Transistors and will rise and fall faster than the outside surface Battery Current vs Motor Current The controller measures and limits the current that flows from the battery Current that flows through the motor is typically higher This counterintuitive phenomenon is due to the flyback current in the motor s inductance In some cases the motor current can be extremely high causing heat and potentially damage while battery current appears low or reasonable The motor s power is controlled by varying the On Off duty cycle of the battery voltage 16 000 times per second to the motor from 0 motor off to 100 motor on Because of the flyback effect during the Off time current continues to flow at nearly the same peak and not the average level as during the On time At low PWM ratios the peak current and therefore motor current can be very high as shown in Figure 18 Instant and average current waveforms on page 44 The relation betwee
195. trol Settings Power Settings R C Ana Specific Close Loop Encoder RC Out Run Console conten O RS 232 M WatchDog Reset Controller for these changes to take effect Motor Control Mode A and B Speed Separate V Closed Loop FeedbackA Analog Encoder I Limit Switches FeedbackB Analog Encoder Chanel 1 Chanel 2 Input Adjustment Linear Linear x EStop Inv Input No Action bd Input E Mode NoAcion O Input F Mode No Action Out C ON when Motors Active I 6 FIGURE 90 Control modes setting screen The screen shown in Figure 90 is used to view and change the controller s main control modes Below is the list of the parameters accessible from this screen 1 Controller Input This pull down menu allows the user to select the RS232 R C or Analog mode of opera tion If the RS232 mode is selected a check box will appear allowing you to enable or dis able the RS232 Watchdog For more information on these modes see e R C Operation on page 101 e Serial RS 232 Controls and Operation on page 121 e RS 232 Watchdog on page 128 e Analog Control and Operation on page 113 2 Motor Control Mode This pull down menu is used to choose whether the controller will operate in Separate or Mixed mode For more information on these modes see Selecting the Motor Control Modes on page 40 3 Input Command Adjustment These pull down menus will let yo
196. tter Receiver Quality Considerations 108 Joystick Deadband Programming 108 Command Control Curves 109 Left Right Tuning Adjustment 110 Joystick Calibration 110 Activating the Accessory Outputs 110 Data Logging in R C Mode 111 SECTION 12 Analog Control and Operation 113 Mode Description 113 Connector I O Pin Assignment Analog Mode 114 Connecting to a Voltage Source 115 Connecting a Potentiometer 115 Selecting the Potentiometer Value 116 Analog Deadband Adjustment 117 PowerOn Safety 118 Under Voltage Safety 118 Data Logging in Analog Mode 118 SECTION 13 Serial RS 232 Controls and Operation 121 Use and benefits of RS232 121 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 RoboteQ Connector I O Pin Assignment RS232 Mode 122 Cable configuration 123 Extending the RS232 Cable 123 Communication Settings 124 Establishing Manual Communication with aPC 124 RS232 Communication with the Encoder Module 125 Entering RS232 from R C or Analog mode 126 Data Logging String in R C or Analog mode 126 RS232 Mode if default 127 Commands Acknowledge and Error Messages 127 Character Echo 127 Command Acknowledgement 127 Command Error 127 Watchdog time out 127 RS 232 Watchdog 128 Controller Commands and Queries 128 Set Motor Command Value 129 Set Accessory Output 129 Query Power Applied to Motors 130 Query Amps from Battery to each Motor Channel 130 Query Analog Inputs 131 Query Heatsink Temperatures 131 Query
197. u select one of five conversion curves on each of the input command values See Command Control Curves on page 46 AX1500 Motor Controller User s Manual 165 Using the Roborun Configuration Utility RoboteQ 4 Emergency Stop or Invert Switch Select This pull down menu allows the selection of the controller s response to changes on the optional switch input Emergency Stop Invert Commands or no action See Emergency Stop using External Switch on page 49 and Inverted Operation on page 49 5 Effect of Digital Inputs This pull down menu allows the selection of the controller s response to changes on either of the two digital inputs See Special Use of Accessory Digital Inputs on page 50 6 Output C Activation This check box will cause the controller to activate when power is applied to one or both motors See Activating Brake Release or Separate Motor Excitation on page 49 Power Settings Controls R C Ana Specific Close Loop Encoder RC Out Run Console Amps Limit ke 52 5 Sh Left Right Motor Adjust 0 ee eee ion Acceleration 3 oe 170 Lye pom ak wae ss wae em what Quick Stop to Max in miliseconds FIGURE 91 Power settings screen The screen shown in Figure 91 is used to view and change the power parameters of the controller 1 Amps limit This slider will let you select the max amps that the controller will deliver to the motor before the curren
198. urn temp AX1500 Motor Controller User s Manual Connecting Sensors and Actuators to Input Outputs lRoboteQ 66 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Optical Incremental Encoders Overview SECTION 7 Installing Connecting and Using the Encoder Module This section describes the Encoder input module that may be added to the AX1500 Optical Incremental Encoders Overview Optical incremental encoders are a means for capturing speed and travelled distance on a motor Unlike absolute encoders which give out a multi bit number depending on the reso lution incremental encoders output pulses as they rotate Counting the pulses tells the application how many revolutions or fractions of the motor has turned Rotation velocity can be determined from the time interval between pulses or by the number of pulses within a given time period Because they are digital devices incremental encoders will measure distance and speed with perfect accuracy Since motors can move in forward and reverse directions it is necessary to differentiate the manner that pulses are counted so that they can increment or decrement a position counter in the application Quadrature encoders have dual channels A and B which are electrically phased 90 apart Thus direction of rotation can be determined by monitoring the phase relationship between the two channels In addition with a dual channel encode
199. utomat ically generate the setting codes for manual entry See Encoder Setting and Testing on page 168 Most computers have at least one but often times two serial ports Look for one or two connectors resembling the illustration in Figure 87 WS FIGURE 87 Look for a 9 pin male connector on your PC If a serial port connector is already connected to something else it may be possible to unplug the current device and temporarily connect the controller as long as the software operating the current device is not running If no serial port is available on your PC use an USB to RS232 adapter Connect the provided serial cable to the controller on one end and to the PC on the other Power the controller preferably using the Power Control terminal with a 12 to 40V battery or power supply with 200mA of minimum output Connect the Controller s Ground to the negative terminal and the Power Control input to the positive of the power supply The controller will turn On If it doesn t verify that the polarity is not reversed Leave VMot unconnected unless you want to exercise the Motors 162 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lRoboteQ Roborun Frame Tab and Menu Descriptions Roborun Frame Tab and Menu Descriptions E RoboRun j x RoboteQ amp a Controller ID RoboteQ AX3500 Controller Configuration Utility a ae ala ETL V 1 9b 06 01 07 Dual Channel jew 0 5
200. wered on if in the R C mode the controller is ready to receive pulses from the R C radio and move the motors accordingly If no pulses are present the motors are disabled After powering on the R C radio receiver and transmitter and if the wiring is correct the controller will start receiving pulses For a preset amount of time the controller will monitor the pulse train to make sure that they are regular and therefore genuine R C radio command pulses After that the motors are enabled This power on Watchdog feature prevents the controller from becoming active from para site pulses and from moving the motors erratically as a result AX1500 Motor Controller User s Manual 107 R C Operation lRoboteQ Similarly if the pulse train is lost while the motors were enabled the controller will wait a short preset amount of time before it disables the motors If the pulses reappear during that time the controller continues without any breaks If the communication is confirmed to be lost the no ctrl message is displayed again Note the Accessory Outputs C will be turned Off when radio is lost Important Notice about PCM Radios PCM radios have their own watchdog circuitry and will output a signal normally a safe condition value when radio communication is lost This signal will be inter preted by the AX1500 as a valid command and the controller will remain active To benefit from the AX1500 s radio detection fu
201. x speed 30 Hex 0 78 2 05 seconds 20 Hex 1 56 1 02 seconds 10 Hex 2 34 0 68 second 00 Hex 0 3 13 0 51 second 31 Hex 3 91 0 41 second 21 Hex 4 69 0 34 second 11 Hex 5 47 0 29 second 01 Hex 1 6 25 0 26 second 32 Hex 7 03 0 23 second 22 Hex 7 81 0 20 second 12 Hex 8 59 0 19 second 02 Hex 2 default 9 38 0 17 second 33 Hex 0 16 0 16 second 23 Hex 0 94 0 15 second 13 Hex 1 72 0 14 second 03 Hex 3 2 50 0 128 second 34 Hex 3 28 0 120 second 24 Hex 4 06 0 113 second 14 Hex 4 84 0 107 second 04 Hex 4 5 63 0 102 second 35 Hex 6 41 0 097 second 25 Hex 7 19 0 093 second AX1500 Motor Controller User s Manual 45 General Operation RoboteQ TABLE 4 Acceleration setting table Acceleration Acceleration Setting Using Setting Using Acceleration per Time from 0 to RS232 Switches 16ms max speed 15 Hex 1797 0 089 second 05 Hex 5 18 75 0 085 second Important Warning Depending on the load s weight and inertia a quick acceleration can cause consider able current surges from the batteries into the motor A quick deceleration will cause an equally large or possibly larger regeneration current surge Always experiment with the lowest acceleration value first and settle for the slowest acceptable value Command Control Curves The AX1500 can also be set to translate the joystick or RS232 motor commands so that the motors respond diffe
202. y be used with most incremental encoder module as long as they include the following features e Two quadrature outputs Ch A Ch B single ended signal e 2 5V minimum swing between 0 Level and 1 Level on quadrature output e 5VDC operation 100mA or less current consumption per encoder More sophisticated incremental encoders with differential outputs index and other fea tures may be used however these additional capabilities will be ignored The choice of encoder resolution is very wide and is constrained by the module s maxi mum pulse count at the high end and measurement resolution for speed at the low end 68 AX1500 Motor Controller User s Manual Version 1 9b June 1 2007 lIRoboteQ Installing the Encoder Module Specifically the encoder module can process 250 000 counts per seconds As discussed in the previous section a count is generated for each transition on the Channel A and Channel B Therefore the module will work with encoders outputting up to 62 500 pulses per second Commercial encoders are rated by their numbers of Pulses per Revolution also some times referred as Cycles per Revolution Carefully read the manufacturer s datasheet to understand whether this number represents the number of pulses that are output by each channel during the course of a 3600 revolution rather than the total number of transitions on both channels during a 3600 revolution The second number is 4 times larger than the

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