MC160 User manual
Contents
1. Q 13 Input GOEVE COS s d 13 M 13 Derivative velocity Gain enr sina ead Ras 14 Efr r Dea Band d 14 Back EMF Factor EEA nt 14 Encoder value e SSSR i E 14 INDUPFACION CC 15 Temperature Protection 15 Integral Gain E c 15 R C Input Dead Band I eus eo rette 15 Feedback Select o cS LE 15 DUR Select coheret eret eb 16 Local Echo ODIO Dati aoi t EE 16 Minimum Drive M a cs sual bacon stoi tuoi bused bcos duced puck bused aves ol nwo 17 Mode Im eic eai aset er EN NME tare 17 R C P ls High Linit N si 17 18 Proportional Position Gain rennes 18 Position Set 18 TOSS E TEE ete e Aah ok talon eL Len 18 Servo Updaltae Hale I e i t e ate a e i ter ee 19 Power Slew Rate pe a e ded D E 19 Delos PST SR PUR T2. Get encoder value from invalid address Send 2ae lt cr gt Get 2ae lt cr gt Minimum Drive M Range 0 255 Default 0 Minimum drive specifies an amount of drive to add to the output in order to overcome drive train friction See Customizations above for more details Servo Mode m Values Off PWM Torque Velocity Position Mode using winch no back drive Position Mode position with back drive mE Default 0 off Servo mode selects the operation of the servo A description of each mode can be found in Tuning Servos below note about Winch position mode when a worm gear drive is used for a servo transmission the output cannot be back driven Torque on the output shaft cannot be transmitted back to the servo motor Winch drive recognizes this special case and resets the PID Integral error term when the drive reaches the position set point Normally the integral error term is needed to hold back drivable servos in position once the set point has been achieved R C Pulse High Limit N Range 0 32 000us Default 1950us The R C pulse limits are the calibrated values for 10096 input Normal R C pulse range is 1 0 to 2 0ms with 1 5ms as the zero value By selecting alternate high and low values the range of 100 to 100 can be shifted and scaled The default values are suitable for most off the shelf R C gear Robot Solutions 2013 MC160 www robot solutions com Users Guide 17
3. 0 7 Default 3 Selects an exponential curve which modifies the R C input signal Curves are useful for greater control of simple power based robots 0 represents a flat line and 7 represents an aggressive curve Copy Parameters c Range 0 3 Copies the contents of registers for channel N to Y Example to copy parameters from the Left register bank to the Right 0sc1 Robot Solutions 2013 MC160 www robot solutions com Users Guide 13 Derivative velocity D Range 0 1023 Default 0 Derivative gain is 5 5 binary number that determines how strongly the servo attempts to maintain a velocity set point See Tuning Servos below for more information about this value Error Dead Band d Range 0 255 Default O Back EMF Factor E Range 0 255 Default 0 Back EMF is used to estimate the torque The back EMF factor is calculated by dividing 8196 by the maximum velocity at 100 drive 255 This is just an estimate as many PMDC motors have non neutral timing and thus different back EMF factors in reverse If your motor has non neutral timing just take the average between forward and reverse velocity ticks period This factor can also be used to compensate for friction The way to do this is to set the servo into the Torque mode with a torque set point of zero Then adjust the Back EMF gain until the system feels frictionless When too large the output when disturbed will accelerate If too low it will s
4. 10 second units it takes to move the output power from 100 to 100 full reverse to full forward Too much slew can make the operation sluggish For large kinetic energy weapons however a large slew is needed to limit the inrush or regenerative braking currents as the device accelerates or decelerates 0 1 or 2 ss 0 100 Note a typical value is 0 to 10 for drive outputs The factory default is 1 Note Proper slew rate operation depends upon the default internal update rate of 50 Hz and works only in the default PWM mode Please do not modify the update rate if you use this function If you do modify the update rate be aware that the slew values will need to be scaled appropriately R C input calibration The MC160 can be calibrated for the particular range of R C pulse widths supplied by the radio Calibration can be done explicitly where the user specifies the minimum and maximum control pulse widths in microseconds or calibration can be done by discovery In discovery mode the control sticks are moved to their extremes and the software records the minimum and maximum values To enter and exit discovery calibration mode Type in Cal lt cr gt on the serial port Robot Solutions 2013 MC160 www robot solutions com Users Guide 6 Calibration mode is indicated by 1 second periodic wink and a text message is printed to the serial port To exit calibration mode do one of the following Type the ESC char
5. Ouen asian 33 Ser er unen 33 Stepper motor en euntes pad avente eee bs 35 36 Mounting instructions and enclosure drawing Robot Solutions 2013 RSMC160 www robot solutions com Users Guide Specifications The MC160 uses custom software to implement a 2 channel high powered servo system The servo uses a quadrature encoder feedback mechanism to control torque velocity and position of the output It includes the capability to control a relay relay not included from a third channel Enclosure size 7 3 x 4 3 x 1 2 not including fan Weight with enclosure 1 5 lbs Dual main channels 160 Amps each Current limiting on both main channels Thermal protection 8 42v battery operation Large power connector accepts 10 32 screws allowing for secure connections using ring terminated wires Full RS232 serial command and setup Standard RS232 communications N81 from 4800 up to 115200 baud Default baud rate is 115 200 N81 Multiple operating modes Normal PWM Torque Velocity Servo Winch Position o Servo Position Thermal power monitoring and limiting e User selected control inputs Serial Command Analog Voltage R C Pulse or Step amp Direction CNC e User selected servo feedback Encoder or Analog Voltage User adjusted hardware current limiting Potentiometer adjustment One potentiometer controls both main channels e
6. User adjustable software current limiting Torque limit in servo mode Robust signal processing for smooth reliable fail safe operation e Indicator LED s show power over current and board status O OO O 1 Note the board is powered directly from the main power terminals Ground is provided to the logic section via direct connection to the main power ground terminal Robot Solutions 2013 MC160 www robot solutions com Users Guide 1 Overview The MC160 brushed Motor Controller provides a flexible platform for controlling brushed DC motors The controller has two power drivers built into it with discreet control The default factory configuration supports operation with R C radios for traditional combat and remote control robotics applications The factory default is easily modified stored in non volatile configuration memory and is restored whenever power is applied In factory default mode the Left R C channel controls forward reverse motion and the Right R C channel controls steering All configuration and control parameters are set via serial menus and configuration strings The serial interface supports standard RS232 signaling from 4800 to 115200 baud using a normal 089 serial cable The entire unit may be configured and controlled via a PC or Laptop using a terminal emulator e g Hyperterm or Terraterm The MC160 supports a variety of servo operation modes position velocity torque amp Servo using a varie
7. feedback or a step amp direction input can control the position of an encoder feedback servo Some operating modes won t work properly with certain feedback mechanisms For example using analog feedback with a velocity servo as the analog feedback signal has mechanical and electrical limits When using analog or R C input methods the input values must be transformed into values suitable for servo operation This is done with the Of command The register value is multiplied by the input value and then divided by 32 to obtain the results The results are then applied to the selected servo set point Serial Besides configuration setup all servo set point parameters are accessible via the serial interface using commands Note depending upon servo mode some set points are overwritten by the servo For example the position servo continuously updates the velocity set point to achieve the position goal The serial interface can be used to examine the current velocity set point but not to modify it R C control Standard hobby radio control equipment or equipment that conforms to the R C signaling standards can be used to input a 1023 count signal This value controls selected set point parameters with a conversion factor A typical use implements a giant R C servo the R C input controls a large servo motor with a potentiometer feedback for position The R C signaling standard calls for 1 0 to 2 0ms pulse width with a 20ms repetition r
8. includes a line editor that supports backspace and escape cancel The editor can optionally disable character echo for machine interface where a computer simply sends commands not expecting data returned There is a third method that facilitates machine communications while echoing the entire command line AFTER it has been processed Besides echo amp no echo there is a third mode that implements a machine friendly interface to the commands This interface does not echo received characters After processing the command the interface echo s the original string with the replaced with a special character and post pended with data if any The special characters are 1 T Error response i e didn t recognize the command 20 8 Normal response data 3 Normal OK response data follows The Set Local Echo command is used to enter this mode and it can be saved in like other parameters Specifically the following will place the unit in the special interface mode gt 0sl2 0612 Note the effect is immediate i e the response is the new acknowledge string but the command still needs to be stored to be active after the next power up Example Set Encoder value Send 0se1234 lt cr gt Get se1234 lt cr gt Robot Solutions 2013 MC160 www robot solutions com Users Guide 16 Example Get Value Send 0 lt gt Get 0se1234 lt cr gt Example
9. 5 Set the Input Factor F to 32 0sF32 6 Set the torque limit to 64 1 4 power 0ST64 7 Setthe velocity limit to 40 about 2 seconds travel 0sV40 8 Set the velocity gain to 128 0050128 9 Set the position gain to 16 905 16 10 Save the settings 0sw Now the servo is set up in a fairly safe mode Be ready to turn power off quickly in case something isn t set up properly 11 Move servo output close to the center position of the feedback pot 12 Enable position servo mode 0sm5 At this point the servo should move or not towards center stick position Test it out by moving the stick gently forward and back The servo should track stick movement If the servo starts to move accelerate and race off in one direction quickly turn off power Either the motor or the feedback potentiometer is connected in reverse fix this problem and try again Because the servo mode was not saved the MC160 will power up in a safe mode allowing changes A complete description of parameters and tuning are beyond this users guide Here are a few notes on improvements that can be made to the parameters 1 The torque limit was set to 1 4 the maximum 2 The velocity limit was set for roughly a 2 second time for the servo to traverse from 100 to 100 position 2047 counts 20 ms loop time 2 seconds 4094 2 02 40 3 The input factor was set so full stick travel 1000 counts only requested 1000 on the position or about 1 2
10. MC160 Servo Controller gt LEE E Os 0 5 4 5 35 5 05 5 95 9 ee Im 8 25 Robot Solutions LLC Robot Solutions 2013 RSMC160 www robot solutions com Users Guide Table of Contents Specifications isnon RO CR etre eine 1 OVeEFVIOW nt nn it n int UD 2 3 C St mizatlO ne MT 4 CRAN VAIO Reste tn E e 5 Input Control C r neo ni nee de 5 Variable Brake B 5 R C input dead DORE SES 5 DEVO MT es non nn RE dnd de 6 FowWwer SIeW Rate dion 6 6 SAVING custom settings WARS 7 T TREE 8 Internal Register 10 Internal Register Description auge nee cuve Rug a onus OOV t a Rue uaa nenna 13 Drake B usine oi ol nl ont EL OUEN 13 Baud Fale D site ee
11. Note despite the large range of limits available the 160 will only recognize pulse width values between 850 and 2150us as valid R C Pulse Low Limit n Range 0 32 000us Default 1050 5 See R C Pulse High Limit for description of register Proportional Position P Range 32000 Default 0 The 160 uses the P register to determine the correction needed for a given error between actual and commanded positions This value Proportional Error Gain term in the PID calculation See Tuning Servos below for more information about this value Position Set Point p Range 0 2 billion Default depends Position set point is the value that the servo drives to when in position mode It is in encoder counts see Encoder above The default value is equal to the default value of the encoder If a non zero value is stored for the Encoder then that value will be used for the initial position value as well The default behavior prevents uncontrolled servo movements when power cycling the MC160 Factory Preset Q Values 0 No mixing 1 Mixing enabled Default 0 The Factory Preset register resets all registers to a known default configuration The optional value selects whether mixing is enabled or not The default configuration is as follows PWM output mode 50 Hz update rate 20ms period R C input selected e 1 050 to 1 950ms R C calibration range e 1 10 second slew e 100 brake at neutra
12. R 19 SOL 0 OE Eo iiie 20 Robot Solutions 2013 RSMC160 www robot solutions com Users Guide Unit Amount Minimum MOVE wis naa re Ep EAR FERE FER FERRE HR ERA 20 Unit Amount Manual Move iii 20 A TINIE V mc NAE 20 Velocity Set point Voss o iud 20 Memo Mesa 21 eir is REM T 21 Menu Miu R 21 Output Drive values 22 C Nntrol Pernod RE near nee etes EM 22 Position 8 Encoder values ence rero ai sca ir d a cu e ER i dui 22 bibend tua ee 22 Ep MEC 23 Tuning discovering servo PID Gain values 24 0 EE 24 re 24 FOTQUC MOOS 2 EE 24 VIO CH ax M M MM 24 FOSIHOInMOOB a pede dade dns 25 Indicators and OulpUIls rrr rar rr rere rsen cecinere nw rc ar sn 25 ICH MEM rrr 25 Temp LED RECRUIT 25 COAST LED Aux Left amp Error Bookmark not defined FWD REV LED Aux Left Right Error Bookmark not de
13. Torque Left Drive Right Drive HS1 Temp HS2 Temp Left over current Right Over current CR Note the left and right over current values are latched upon the over current event and are not cleared until printed with the next 5 command t c lt cr gt Print out the current temperature of the power driver heat 160 starts to fold back the power levels at 60 deg C and fully shuts off the driver above 130 deg C The fan will turn on at temperatures over 40 deg C e T lt cr gt Displays the system uptime v c lt cr gt Displays the current velocity Velocity is the change in encoder value per unit time See tuning below for more details lt gt Machine commands used to control the servo Output Drive values The MC160 uses 8 bit PWM hardware It uses values from 0 to 255 to represent 0 100 drive Drive can also be in reverse Hence drive PWM values are specified from 255 to 255 Control Period Control cycle period is a whole number from 0 to 255 that is a multiplier of the basic 1 millisecond system tick rate or 0 to 255 second period When 0 the servo mechanism is disabled and the output allowed to coast Position amp Encoder values Position is in terms of the encoder counts The encoder resolution 2 gives the total number of counts per revolution Velocity Velocity is in terms of encoder counts loop period It depends upon the loop rate and the e
14. acter on the serial interface Exit mode is indicated by the status LED returning to its previous flash pattern and a short message printed to the serial interface NOTE Once calibrated the values need to be saved in one of the user configuration slots or they will be lost the next time the controller s power is cycled Factory default values for all channels Minimum 1 095 milliseconds Maximum 1 950 milliseconds Although the allowable range is anywhere from 0 to 32 milliseconds the controller will only recognize pulse width values between 0 850 and 2 150 milliseconds long The recognized values are relaxed enough for all known R C pulse gear including IFI robot controllers Saving custom settings w All settings and calibration is performed on the running system When power is removed the current values are lost The MC160 provides four non volatile memory slots for storing parameters Four sets can be stored and the 160 will restore the last accessed slot whenever rebooting Settings and calibrations are stored with the following command string 210 1 2 or 3 sw When power is lost and restored the MC160 will restore the last slot stored If an alternate slot is needed it can be recalled with the following command 0 1 2 or 3jgw After recall if the power is lost the MC160 will restore the last recalled or stored slot Robot Solutions 2013 MC160 www robot solutions com Users Guide 7 User Interface Th
15. and command values v V p t and T uM Mode 1 Set mode m to 1 Set torque set point t to 255 and measure velocity 3 Adjust loop rate r for a maximum velocity between 50 and 1023 The actual best value will depend upon the resolution of the encoders and the mass of the drive train and torque capabilities of the motor Some experimentation may be required 4 Repeat for a torque set point of 255 5 Set the back EMF gain E to 8196 divided by the average max velocity e g 8196 2 V forward V reverse Torque Mode 2 Adjust Back EMF E gain until the unit feels frictionless The motor should be easy to spin both forward and reverse Most PMDC motors have different back EMF constants for forward and reverse so some compromise is needed If it is difficult to tell then simply leave it at the calculated value Otherwise adjust the calculated value until the entire mechanism feels relatively frictionless By increasing the calculated value of B friction within the mechanism can be partially compensated Be careful too much extra Back EMF can cause instability in the servo operation At low speeds slip stick friction needs extra Back EMF to overcome but this becomes too much at higher speeds and can cause oscillations It is better to use Minimum PWM value to compensate for low speed slip stick friction Velocity Mode 3 1 Set the torque set point T to maximum 255 2 Adjust velocity gain D until shaft
16. any other motor controller In rare cases where the motor controller fails it can lock in the ON position with no ability to stop the motor that is being controlled All users should utilize a safety disconnect to the main power to allow for the safe disconnect of the power Failure to do this can result in damage to the controller Never remove the power to the motor controller while the motor is running This may damage the controller Note if using a contactor or disconnect switch you should provide a diode to the power source to discharge the power created by a spinning motor as it acts as a generator The cathode side is connected to the battery in parallel with the contactor or switch e While it was designed to withstand significant abuse normal anti static ESD protection handling procedures should be observed Copyright 2013 Robot Solutions LLC Author David Moeller Larry Barello amp Christian Wolterman Contact info David Robot Solutions com Larry barello net Contact the author with problem reports or fixes feature requests or additions and questions They are welcomed and will be incorporated as time permits Robot Solutions 2013 MC160 www robot solutions com Users Guide 26 Appendix B Input methods Control Input Methods The MC160 features a variety of control and feedback mechanisms These mechanisms can be independently assigned to each channel Thus an R C receiver can control a servo with an analog
17. ate The MC160 can correctly decode pulse widths from 850 to 2 150 ms and as fast as 300 Hz repetition rate on each channel The factory default calibration sets the 100 value to 1 050 to 1 950 ms respectively The default values should be compatible with all off the shelf R C gear The MC160 includes a calibration method to adjust the default limits or the serial interface can directly set the 100 timing Analog Signal Analog signals are 0 5v values that are converted into a 2047 count signal See Feedback Methods below for important information about analog signals Step amp Direction Step amp Direction input simulates a stepper motor interface commonly found on CNC machinery Each step moves the input function one encoder count Robot Solutions 2013 MC160 www robot solutions com Users Guide 27 Feedback Input Methods Encoder Industry standard quadrature encoders using 2x decoders i e the resolution is twice the slot count There is no support for index marks or limit switches The MC160 can support up to three channels of encoder with a maximum sustained encoder count rate of 100 kHz shared by all channels If two channels are active both can count up to 50 kHz simultaneously The wiring information for the MC160 connectors can be found here http www usdigital com products connect 5pin finger latching shtml Analog Signal Analog feedback signals are 0 5v converted into a 2047 count value Th
18. back EMF value As the velocity increases the overall drive will increase to maintain the torque The torque limit sets how much additional drive is allowed above the back EMF value The additional amount divided by 255 is the fractional amount of the stall current and torque that will be generated An additional note torque and rotational mass will determine acceleration and deceleration time for the servo limiting torque one can control acceleration and deceleration of the servo Or one can limit maximum current draw thus preventing circuit breakers from tripping Robot Solutions 2013 MC160 www robot solutions com Users Guide 19 Set point 1 0 255 Default 0 torque value used servo Torque mode other mode this value is either ignored or continuously overwritten by the higher level servo algorithms Velocity to be exact Unit Amount Minimum Move U Range 32 000 Default 0 This register is in encoder counts and can be used to smooth rapid small input changes by preventing a move from starting until a certain absolute change has been noted in the set point This register only affects position servo modes Unit Amount Manual Move u Range 32 000 Default 0 The MC160 has inputs that can be used to manually slew the servo position without changing any internal parameters or set points This is useful for setting zero points on servo controlled
19. e Factory Preset under Internal Register Descriptions for complete details Robot Solutions 2013 MC160 www robot solutions com Users Guide 32 Giant By adding potentiometer feedback to motor output typically gearbox the 160 serve as a two channel servo controller L R R C Receiver Left Motor 5v 0 5 gt RS160D 5 S Configuration and Control 4800 38 4k baud Right Motor Set Up amp Tuning Because of the power available in the MC160 it is recommended one use quality precision wire wound multi turn potentiometers for the feedback mechanism A typical unit would be a 5 turn 1k pot Bourns 3590S 2 102L The parameters listed below are general values that need to be modified for each particular situation Read the section on servo tuning for more details Certain values like the Back EMF value cannot be experimentally determined with potentiometer feedback rather they need to be calculated The same is true for reasonable velocity limits 1 Reset factory defaults with no mixing 90500 Robot Solutions 2013 MC160 www robot solutions com Users Guide 33 2 Verify that forward stick movement causes an increase analog feedback voltage l e that positive drive output matches positive feedback Set the operating mode to OFF 905 0 4 Select the analog feedback mechanism 20sJ1
20. e host controller communicates through a standard DB9F RS232 serial port compatible with standard computers In addition to entering in data in command packets the RS232 port supports basic line editing with the backspace key The control interface also has a simple menu system that allows immediate feedback about servo performance Below is representative of the text printed to the serial port at power on It includes many of the commands and settings available Please refer to appendix A for a complete list of parameters Some terminal programs may need to be configured to show the output correctly If you are not seeing the below example then check your terminal programs setting for how it sends and received carriage returns MC160 p lt cr gt Parameters lt gt Reset Servo E Stop a lt cr gt Analog Repetition Rate in responses per second d lt cr gt Drive e lt cr gt Encoder S lt cr gt Streamlined Parameters t lt cr gt Temp v lt cr gt Velocity lt adx gt lt mod gt lt reg gt lt val gt Command Packet lt cr gt lt adx gt 0 left 1 right 2 aux lt mod gt s set a actual c current lt val gt Decimal number default 0 reg m O off l pwm 2 torq 3 vel 4 Winch 5 Position 6 Alt M Minimum Drive value to move output Default 0 d Position Error Deadband Default 255 f Thermal protection on 1 off 0 volatile can t be stored p Position Set
21. e internal converter has only 1024 values A digital filter used to reduce noise produces a 4096 count intermediate value which supplies the feedback and control registers This works reasonably well HOWEVER NOTE WELL if the analog signal is very clean and noise free only 1024 distinct values can be detected So even though the system works with a 2047 value the control resolution is only 511 counts Robot Solutions 2013 MC160 www robot solutions com Users Guide 28 Interface Wiring Information Analog DBISF HD SMI Analog signals are provided on the DB15HD connector The above interface shows an example of a left channel analog potentiometer input wiring Other direct analog signals can be connected directly to the header using normal CMOS analog signal considerations The 5v and ground supplies are regulated and filtered on the MC160 controller reasonable amount of current 50 200 ma may be drawn from these supplies to power off board electronics There are two more channels available for the AUX servo but these signals are not physically available on the MC160 controller Robot Solutions 2013 MC160 www robot solutions com Users Guide 29 Step amp Direction The CNC interface Step and Direction uses the Radio Control Servo Cables left and right channels and DB15HD connector to supply the input signaling connections The Radio Control connectors provide the high sp
22. e mode R C PWM mode straight or mixed S set a current slot g get slot d ESC lt amp gs0 Enter R C Calibration mode Enter Print register values PWM Drive Encoder count Exit R C Calibration mode R C input in uS R C input Normalized Print Parameters Reset Servo stop Streaming parameters Temperature Velocity counts loop NOTE For the most up to date command info type lt CR gt into the serial interface for a list of all commands Robot Solutions 2013 Users Guide MC160 www robot solutions com 21294 Internal Register Description The following is a summary of commands used to set and query internal registers of the MC160 Most commands operate on channels and apply or print values A few commands have no register value Please reference Customizations under Factory Defaults above for details of the register command format Brake B Range 0 31 representing 0 to 100 brake Default 31 Only applies when output drive is neutral 0 drive on channels 0 1 and 2 Left Right and Auxiliary Baud Rate b Range 0 5 representing the following baud rates 4800 9600 19200 38400 57600 115200 Default 5 115200 IANO Changes to baud rate take effect after the system is reset by a power cycle Channel value must be 0 but is otherwise ignored Remember to save new baud rate in User Memory with the w register R C Input Curve C Range
23. e1 SpinMode2 Relay p Position Set point 2 00E 09 2 00E 09 0 CHO 2 to Position control loop P Position Error Gain 32768 32768 0 0 2 11 5 r Servo loop rate 0 255 10 0 2 Looprate in milliseconds 0 off S Power Slew 0 100 0 2 0 10 sec by 1 sec Time to slew from 100 to 100 power t Torque Set point 255 255 0 CHO 2 Input to Torque control loop T Torque Limit 255 255 0 CHO 2 20 1009 pwm Unit amount for manual move 32768 32768 0 CHO 2 In Encoder Counts position error dead band for Step Dir interface Unit amount for minimum U move 32768 32768 0 CHO 2 Counts Velocity Set point 32768 32768 0 CHO 2 Input to control loop V Velocity Limit 32768 32768 0 2 Encoder counts loop Radio Input Curve 0 31 Global Input Dead band 0 63 RC 0 3 uSeconds around zero n Low Limit 850 2150 RC 0 3 R C Pulse width N Upper Limit 850 2150 RC 0 3 R C Pulse width Mixing 0 1 Global Left Right Off On Misc b Baud Rate 0 5 Global 4800 9600 19200 38400 57600 and 115200 f Temperature Protection 0 1 Global Volatile enabled after reset Robot Solutions 2013 MC160 www robot solutions com Users Guide 11 Q W Lower Function Enter Boot loader User Interface Mode Compatible Preset Write Load values to from EEPROM User Interface Menu Upper n a Default n a Applies to n a Global Global Global Notes Not implemented no echo echo machin
24. eed step inputs and the DB15HD connector provides the direction inputs ry CNS DBISF HD SMT EELAY CUT Robot Solutions 2013 MC160 www robot solutions com Users Guide 30 Incremental 160 encoder connections are provided on the DB15HD connector The interface is designed to connect to quadrature encoders such as US Digital encoders FINV CN5 DB15F HD S DB Description Color typical Pin 3 Ground Brown or Black 7 A channel Blue or White 6 5VDC power Orange or Red 1 B channel Yellow or Brown Figure 1 Typical encoder cable Robot Solutions 2013 MC160 www robot solutions com Users Guide 31 Appendix D Example applications Factory Default Receiver Left Motor I E Right Motor E Factory default configuration supports traditional differential drive remote control robot operation Combat robots for example The default configuration enables channel mixing so the LEFT input controls overall speed and the RIGHT input controls steering RS160D 4800 38 4k baud Configuration and Control The configuration consol is not needed for operation but can be used to alter parameters to suit the users needs input dead band control curve mixing Use the following commands to return to the factory default configuration 90501 Se
25. encoder positions are initialized to the current set point The servo operating mode is always set to OFF Changing from OFF to one of the various servo modes will cause the encoders to be reset to the current position set points Indicators and Outputs Status LED This LED winks once per valid channel per two second period With all four channels connected it appears like four rapid flashes and a long pause When in calibration mode the LED flashes evenly without pause FLTL FLTR LEDs This LED is off under normal conditions and will turn on when the left or right channel s experience overcurrent and are being limited by the software Robot Solutions 2013 MC160 www robot solutions com Users Guide 25 Limitations Warrantees Robot Solutions LLC robot solutions com provides no warrantee of suitability or performance for any purpose for the MC160 Use of the MC160 software and or hardware is with the understanding that any outcome whatsoever is at the users own risk Robot Solutions LLC sole guarantee is that the software and hardware performs to the best of our knowledge in compliance with this document at the time it was shipped Support For additional information and or support send an e mail to mailto Support 2 Robot Solutions com General Guidelines and safety precautions e This controller should not be used in life critical applications Caution does need to be taken with the use of the MC160 as with
26. equipment as the MC160 does not have limit or zero switch inputs Refer to Appendix C for a wiring diagram for manual move inputs Manual move only works in mode 0 safety reasons When a manual move switch is closed the MC160 temporarily switches to position mode and makes the move A short while after the move the MC160 returns to mode 0 off Closing the manual move switches in any other mode has no effect Velocity Limit V Range 1023 Default 0 The velocity limit controls how fast the MC160 moves the output to a new position set point Velocity is in terms of encoder counts per servo update period Velocity Set point v Range 1023 Default 0 Robot Solutions 2013 MC160 www robot solutions com Users Guide 20 This register sets the velocity set point when velocity servo mode When in position modes the position servo sets this value while moving to a new position Setting this value any mode other than position servo has no effect It can be read at any time Write User Memory w Range 0 3 Default 0 This command does not have a parameter The channel number 0 3 is used to select one of four memory slots to store custom parameters The last slot referenced either written or recalled will be used for initialization in future power cycles Channel Mixing x Values 0 No mixing 1 Mixing enabled Default 0 No mixing Channel mixing is typically used in R C control situation where a
27. f the power driver This value is volatile meaning it cannot be saved and will be reset to zero after each power cycle Integral Gain 1 Range 32 000 Default 0 Integral gain is used in the PID calculation for correcting velocity errors See Tuning Servos below for more information about this value R C Input Dead Band i Range 0 255us Default 10us R C input dead band is specified in microseconds us The specified value will be used around the middle or zero value which is 1500us The default value is 10us around 1500us Feedback Select J Range 0 Encoder 1 Analog Voltage 0 5v Default 0 Encoder The J registers selects the feedback method for the servo controller Analog feedback is typically a 10 100k ohm linear potentiometer connected between ground and 5v The encoder method uses standard inexpensive industrial quadrature encoders to determine direction and speed of rotation See Appendix B for more details on input and feedback methods Robot Solutions 2013 MC160 www robot solutions com Users Guide 15 Control Input Select Range 0 Serial command 1 R C input 2 Analog Voltage 0 5v 3 Step amp direction input Default 1 R C input See Appendix B for more details on input and feedback methods Local Echo Option 1 Range 0 No Echo 1 Echo typed characters 2 Special Machine interface mode Default 1 echo typed characters The serial interface
28. fined Limitations and 26 SUPPORT San Rd ne 26 General Guidelihi8s 5 ei ed ia SERRE FE DU MERE NE 26 Appendix A System Software Updates Error Bookmark not defined Appendix B Input methods uetus uoce ose tov iki an en see Gk o CE Ce DU nt cU D Go ca Dude QUAE REG 27 Control Methods iesu ied ae 27 DE D EDD D E 27 ttt 27 Signal suuin oL EE HELD HL WEE Ce Uo 27 Step amp Bis e 27 Feedback Input MethodS 28 591012 28 Analog Signal ai a eto 28 Appendix C Interface Wiring Information 29 PAULO Ra RE UT RETE TREE TM EE ncaa Meine ea ea 29 Slop amp en re ee 30 Iineremental Encode 21 Manual MOV Man Sie Error Bookmark not defined Appendix D Example applications ns 32 Robot Solutions 2013 RSMC160 www robot solutions com Users Guide Factory Detatf EE RE Giant CSN
29. g varies from 0 coasting to 31 10096 Braking is regenerative and will generate current to re charge the supply battery The string to set the brake amount 210 1 or 2 sB 0 31 Braking is specified independently for the Left Right or Aux channels hence the 0 1 or 2 in the first field The Factory default is 10096 brake R C input dead band i Specifying the R C input dead band can help prevent jitter when control sticks are in neutral position The dead band is specified in microseconds 1 2 or 3 si 0 63 Robot Solutions 2013 MC160 www robot solutions com Users Guide 5 Factory default value is 10 microseconds Minimum Drive M Often robotic drive systems have significant friction to overcome before the robot moves Minimum drive helps compensate for that by boosting the PWM values 210 1 2 sM 0 255 Note 10 25 are normal values The best way to set this parameter is to use the serial interface to display drive values and move the trim stick until the drive train just starts to move then record the values and use that as a starting point Factory default is 0 Power Slew Rate 5 For high power systems suddenly changing power levels can introduce shock and or large current draws The former is hard on the mechanical system and the latter can cause trouble with batteries The MC160 has a variable power slew function that is only active in PWM mode The slew function specifies the time in 1
30. ions com Users Guide 35 7 17 js 5 675 3 450 0 14 THRU 4 pls UNLESS OTHERWISE SPECIFIED NAME DATE DIMENSIONS ARE IN INCHES DRAWN TOLERANCES FRACTIONAL TITLE ANGULAR MACH BEND TWO PLACE DECIMAL PLACE DECIMAL APPR INTERPRET GEOMETRIC PROPRIETARY AND CONFIDENTIAL 2 TOLERANCING PER COMMENTS THE INFORMATION CONTAINED IN THIS MATERIAL SIZE DWG NO REV DRAWING IS THE SOLE PROPERTY OF lt INSERT COMPANY NAME HERE REPRODUCTION IN PART OR AS A WHOLE FINISH A M 1 60 WITHOUT THE WRITTEN PERMISSION OF NEXT ASSY USED ON lt INSERT COMPANY HERE IS APPLICATION DO NOT SCALE DRAWING SCALE 1 1 WEIGHT SHEET 1 OF 1 PROHIBITED 5 4 3 2 1
31. is difficult to turn but does not oscillate Usually 1 2 of the value that causes oscillations is pretty good 3 Adjust Velocity Integral gain 1 until shaft becomes very stiff but again without any oscillations It should return to the zero position after any displacement 4 the velocity SP v to some small value and verify that the motor turns slowly and smoothly Some playing around with the D and terms may be needed If the system does not seem tight enough experiment with faster loop rates Adjust the previously discovered values by the change in loop rate i e if 1 2 the period then double the gains etc Robot Solutions 2013 MC160 www robot solutions com Users Guide 24 Position Mode 4 1 Set velocity set point v to the maximum recorded in PWM mode 2 Adjust position gain so is very stiff but does not oscillate Usually very small position gains are needed i e 1 16 3 Reduce velocity set point to whatever maximum is required 4 Experiment with driving the system to various positions using both low and high velocity limits Verify smooth oscillation free operation for each condition Whenever modes are changed various parameters may be reset In particular the Integral error term is reset and the encoder position is forced to the current position set point if the new mode is position servo Upon boot configuration parameters are read out and set assuming no checksum error and the
32. iting logic 100 power is not allowed Robot Solutions 2013 MC160 www robot solutions com Users Guide T Customization There are variety of customizations that can be applied to the MC160 Channel Mixing for single or dual stick operation Calibration of R C inputs Adjustable control curves Control Dead band Minimum Drive values for output Variable braking when neutral Variable power slew rate Up to four different sets of customizations may be stored and recalled Pk aret What follows are customizations that apply to the default factory configuration These registers are described in detail in this section and primarily apply to simple R C control of power a typical remote control robot configuration There is a complete description of all customization registers further on in this document under nternal Register Description In general configuration parameters are entered in the following form channel s g a register value Each command starts with the character The second character is a number indicating which channel The channels are numbered as follows 0 Left R C input or Power output 1 Right R C input or Power output 2 Aux R C input flip or relay control The third character indicates the operation 5 Set the value into the register g Get the value stored in non volatile memory a Get the actual current operating value Note for some commands the programmed value is not acted upo
33. l stick position e Mild 3 curve Robot Solutions 2013 MC160 www robot solutions com Users Guide 18 e other registers to default values Note The default setting for corrupt or brand new user storage is QO Servo Update Hate r Range 0 255 ms Default 0 ms This value sets the basic loop rate for the servo calculations Most all other parameters and values depend upon this value Values can range from 0 off to 1 1 KHz to 255 about 4 Hz A value of 20 must be set to achieve 50 Hz Power Slew Hate s Range 0 100 Default 1 Power slew affects how fast the drive value can change Each increment represents one tenth of a second or 100ms The default value takes 100ms to slew the power from full forward 100 to full reverse 100 Power slew rate only affect servo mode 1 PWM and requires an update rate of 50 Hz to work properly Torque Limit T Range 0 255 Default 0 Torque Limit used in conjunction with Back EMF factor E can fairly accurately limit the maximum current draw and thus torque of the drive motor At stall zero velocity zero back EMF 100 drive 255 will produce maximum torque and current draw Fractional drives will produce fractional torque and current draw When the motor is rotating the back EMF counters the drive reducing torque and current In order to maintain constant torque and current draw over a wide range of velocities it is necessary to add the drive value to the
34. low down and stop When just right it will continue in the same direction and speed indefinitely e g frictionless Make sure you test at fairly high velocities as the back EMF values are inaccurate at low velocities Typical back EMF factors are in the 8 30 range Encoder value e Range 2 billion Default 0 This register contains the current encoder value often thought of as position By writing this register the position can be set to any value The value in this register will be restored when loading user parameters So if you want the default boot value to be zero then zero this register before saving user parameters The MC160 encoder input implements a 2X quadrature decoder One multiplies the encoder slot count e g 64 by 2 to determine the total number of counts per revolution Robot Solutions 2013 MC160 www robot solutions com Users Guide 14 Input Factor Range Default O The number multiplied by the selected input method R C or Analog input to generate the appropriate control value This number is divided by 32 after the multiplication so fractional values may be specified See Appendix B for more information on input methods Temperature Protection Override f Range 0 amp 1 Default 0 This register allows temporary override of temperature fold back function within the MC160 When set to 1 fold back is disabled and full power be delivered regardless of the heat sink temperature o
35. lutions com Users Guide 2 Factory Default As shipped from the factory the MC160 firmware will boot into a default minimal function mode The feature set is as follows Basic PWM control 9596 reverse to 95 forward power R C input control 10us dead band Single stick channel mixing Normal R C calibration Mild input curve 100 brake with neutral command 1 second power slew rate Serial communications set at 115200 baud QU ED ED pe S TOES At any time the user can reset the unit to the factory values with a simple command via the terminal interface The MC160 uses a standard DB9 RS232 cable and should connect to any PC or laptop computer Newer computers may only have USB connectors and an inexpensive USB to Serial adapter would be required Connect a terminal emulator e g Hyperterm with the following settings 115200 baud 8 bit no parity One stop bit At the prompt type in the following characters 90500 lt gt lt gt represents the ENTER key If you desire single stick control type in the following string instead 20501 lt gt NOTE Values not stored non volatile memory by default You can test these modes out before you save them but you need to write the values out before they stick The command to do this is 0sw0 lt cr gt The non volatile store and how to use it is described in a later section 2 For reasons related to the hardware current lim
36. n until the system is reset hence the a modifier The fourth character is the register that contains the value being adjusted The final field is a signed decimal number i e it can be negative If this number is left out a 0 will be used instead All commands are terminated with a Carriage return enter cr Robot Solutions 2013 MC160 www robot solutions com Users Guide m typical command might be Set Left Channel Drive 250 would look like this 0sd250 The command to read the drive for the Left Channel and print it out would look like this 0 Channel Mixing x Channel mixing is a global value not associated with R C input channels or PWM output channels The channel value is ignored The value can be either 0 Tank 1 Mixed Mixing uses the Left channel as throttle and mixes in the Right channel as steering This is commonly used to implement single stick control for steering amp throttle in remote control robots 205 0 Disable Mixing 0sx1 Enable Mixing Input Control Curve C A variable exponential control curve can be applied to the R C input The curve value applies to all channels The amount ranges from 0 which is flat to 7 which represents a fairly aggressive curve 0sC 0 7 The factory default is a mild curve of 3 Variable Brake B When control sticks are in neutral position the MC160 can apply a variable amount of braking effort Brakin
37. ncoder resolution For example with 120 rpm no load maximum shaft speed and an encoder resolution of 100ppr quadrature decoding a 10 ms loop rate gives the maximum of 120rpm 60 100cpr 2 10ms 4 This is not useful so the loop rate needs to be stretched out to 100ms for a maximum velocity of 40 It is an engineering decision whether to increase the encoder resolution or increase the loop period in order to get reasonable range of velocity In this example whether to increase the period or increase the Pulses per Revolution ppr of the encoder would be determined by the rotational mass of the system light systems that react fast need fast loop rates thus higher ppr Large slow to accelerate systems might get away with a longer loop rate Robot Solutions 2013 MC160 www robot solutions com Users Guide 22 Torque Set point is dimensionless number from 0 255 with 0 no torque and 255 being 100 at stall It is determined by the internal 8 bit PWM hardware Robot Solutions 2013 MC160 www robot solutions com Users Guide 23 Tuning discovering servo PID Gain values Start with zero for all parameters before enabling the servo Then precede through the various servo modes to adjust each gain value In the instructions that follow the commands are referenced by their register name A full command must be used to set the value of the register Off Mode 0 Zero all gain parameters P D and E
38. point u Unit amount for manual move U Unit amount filter r Loop Rate 0 255 t Torque Setpoint 255 T Torque Limit 0 255 v Velocity Set point V Velocity Limit w Write values to EEPROM l 0 no echo 1 echo 2 Machine I O copy from adx to val help gt On a unit with corrupt or blank configuration the default operating mode is 115 200 baud with local echo enabled The local echo option repeats every character received so that the user can see what they are typing Robot Solutions 2013 MC160 www robot solutions com Users Guide 8 The status of the non volatile storage be determined by the status LED on the MC160 It has two states 1 Blinking approximately once a second Normal operation non volatile storage valid 2 Blinking rapidly approximately four times a second Non volatile storage corrupt or never programmed after erase Examples of commands When fresh programmed the non volatile store will be corrupt and light flash rapidly and the default baud rate is set to 115200 Change it to 19200 gt 90502 Set baud rate 2 19200 gt 0sw Write configuration to user slot 0 gt 1gb Reports stored baud rate 2 gt 1ab Reports operating baud rate 5 The actual baud rate is the old value 115200 until the unit has been power cycled The current baud rate is the programmed value Reset the unit to load the new baud rate Normally the MC160 interface
39. prints information in response to user input However for most menu items not registers an optional repeat modifier may be specified which causes the MC160 to periodically print out information The repeat modifier is just a number after the single character command The number is the repetitions per second Robot Solutions 2013 MC160 www robot solutions com Users Guide 9 Internal Register Summary Robot Solutions 2013 MC160 www robot solutions com Users Guide 10 Applies Function Lower Upper Default to Notes Servo 0 31 31 0 2 100 braking at zero drive only values Global Funky just copy servos d Position Error Dead band 255 255 0 0 2 D Velocity Error Gain 32768 32768 0 CHO 2 11 5binary fraction e Position encoder 2 00E 09 2 00E 09 0 2 32 bit number Back EMF factor 32768 32768 0 CHO 2 Used to estimate torque 12 4 Number Multiplier for Normalized R C value used as set points for various servo F Input Factor 32 000 32 000 8 2 modes Integral Error Gain 32768 32768 0 2 11 5 binary fraction Input Select 0 3 0 2 Serial Radio Analog or Step Dir J Feedback Select 0 1 0 CHO 2 Encoder Analog Position Limit 2 00 09 2 00 09 CH 0 2 Implemented yet M Minimum Drive 255 255 0 CHO 2 Minimum PWM drive to move output De dead band m Mode 0 6 1 CHO0 2 0 Off PWM Torque Velocity Winch Position AltWinch SpinMod
40. single stick is used for throttle and steering When enabled mixing uses the LEFT channel for throttle and the RIGHT channel for steering Menu Items lt gt Displays analog channel inputs 0 7 This command is not too useful since only channels 6 amp 7 are used and are displayed better with the t command c is a modifier If you enter 5 lt gt the analog values will be continuously displayed five times per second d c lt cr gt Displays output drive value The uses eight bit PWM hardware for 255 levels of output So 0 to 255 represents 0 100 Negative numbers are reverse power Again the modifies the command for continuous output E c lt cr gt Displays encoder values Useful for checking operation of the encoder and verifying that the wiring is correct Positive PWM shaft rotation needs to produce positive encoder changes lt gt Print out a short summary of all servo parameters and current operating conditions See section on tuning for more details lt gt Print out a summary of the R C parameters current operating conditions S c lt cr gt Displays streamlined parameters The parameters include the following in the order shown Robot Solutions 2013 MC160 www robot solutions com Users Guide 21 Left Mode Right Mode Left Encoder Right Encoder Left Velocity Right Velocity Left Torque Right
41. the possible travel 4 Back EMF is roughly 8192 max velocity of the feedback signal The velocity is the number of encoder ticks servo loop at maximum RPM Knowing that the feedback signal has a range of 4096 and the default loop rate is 20ms use the gear ratio to calculate the maximum velocity at maximum motor RPM and the back EMF factor 5 Depending upon power of the motor inertia of the control system a 50 Hz loop rate may be too slow If the loop rate changes then various parameters will change proportionally Robot Solutions 2013 MC160 www robot solutions com Users Guide 34 Stepper motor Direction Controller JU Left Motor Encoder Follow Error RS160D CNC Direction Right Motor Controller Encoder 4800 38 4k baud Configuration and Control CNC Step control advances the position set point one count for each 0 to 5v step input Ov direction reverse 5v direction forward Three channels of CNC control are available on the MC160 with the addition of a third OSMC motor driver board Following error is a normally open CMOS output that is shorted to ground when the difference between the feedback position and the position set point exceed a fixed amount specified in the U register unit amount manual move The following error output is only enabled when CNC is selected as the input mode Robot Solutions 2013 MC160 www robot solut
42. ty of input and feedback methods The MC160 accepts the following control input signals serial commands Analog voltage 0 5v Radio Control signaling or Step amp direction For servo feedback the 160 accepts either analog voltages 0 5v potentiometer or quadrature encoders Inexpensive industrial encoders can be obtained from www usdigital com The relationship between the various control inputs output are set by serial configuration commands and the serial interface is always available for adjusting parameters regardless of the operating mode Some examples of systems possible with the MC160 1 A simple radio controlled motor controller Radio receiver power is supplied by the MC160 BEC You do not need an external radio battery 2 Alarge R C style servo can be created by combining the R C control input with the analog voltage feedback 3 Using R C input and encoders enables velocity control which is superior for the handling of remote control robots 4 Serial input with encoder feedback enables machine controllable subsystems such as steering or brake controllers in large vehicles 5 Step amp Direction input with encoder feedback simulates large high powered step motors with inexpensive PMDC motors The step amp direction feedback interfaces directly with CNC software The Controller automatically loads the last saved or recalled set upon power up supporting unattended operation Robot Solutions 2013 MC160 www robot so
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