What is the Encoder Istance of the AMT103?

#1

I have this problem, i have a gimbal motor and AMT103 Encoder. I used the code of the site but when I start program the motor go crazy, I can’t controll it and controll the right angle that I want.

This is the code:

#include <SimpleFOC.h>
// software interrupt library
#include <PciManager.h>
#include <PciListenerImp.h>

// BLDC motor & driver instance
BLDCMotor motor = BLDCMotor(14);
BLDCDriver3PWM driver = BLDCDriver3PWM(9, 10, 11, 8);
// Stepper motor & driver instance
//StepperMotor motor = StepperMotor(50);
//StepperDriver4PWM driver = StepperDriver4PWM(9, 5, 10, 6,  8);

// encoder instance
Encoder encoder = Encoder(2, 3, 8192, A0);

// Interrupt routine intialisation
// channel A and B callbacks
void doA(){encoder.handleA();}
void doB(){encoder.handleB();}
void doIndex(){encoder.handleIndex();}
// If no available hadware interrupt pins use the software interrupt
PciListenerImp listenerIndex(encoder.index_pin, doIndex);

// angle set point variable
float target_angle = 0;
// instantiate the commander
Commander command = Commander(Serial);
void doTarget(char* cmd) { command.scalar(&target_angle, cmd); }

void setup() {
  
  // initialize encoder sensor hardware
  encoder.init();
  encoder.enableInterrupts(doA, doB); 
  // software interrupts
  PciManager.registerListener(&listenerIndex);
  // link the motor to the sensor
  motor.linkSensor(&encoder);

  // driver config
  // power supply voltage [V]
  driver.voltage_power_supply = 12;
  driver.init();
  // link the motor and the driver
  motor.linkDriver(&driver);
  
  // aligning voltage [V]
  motor.voltage_sensor_align = 3;
  // index search velocity [rad/s]
  motor.velocity_index_search = 3;

  // set motion control loop to be used
  motor.controller = MotionControlType::angle;

  // contoller configuration 
  // default parameters in defaults.h

  // velocity PI controller parameters
  motor.PID_velocity.P = 0.2;
  motor.PID_velocity.I = 20;
  motor.PID_velocity.D = 0;
  // default voltage_power_supply
  motor.voltage_limit = 6;
  // jerk control using voltage voltage ramp
  // default value is 300 volts per sec  ~ 0.3V per millisecond
  motor.PID_velocity.output_ramp = 1000;
 
  // velocity low pass filtering time constant
  motor.LPF_velocity.Tf = 0.01;

  // angle P controller
  motor.P_angle.P = 20;
  //  maximal velocity of the position control
  motor.velocity_limit = 4;


  // use monitoring with serial 
  Serial.begin(115200);
  // comment out if not needed
  motor.useMonitoring(Serial);
  
  // initialize motor
  motor.init();
  // align encoder and start FOC
  motor.initFOC();

  // add target command T
  command.add('T', doTarget, "target angle");

  Serial.println(F("Motor ready."));
  Serial.println(F("Set the target angle using serial terminal:"));
  _delay(1000);
}

void loop() {
  // main FOC algorithm function
  // the faster you run this function the better
  // Arduino UNO loop  ~1kHz
  // Bluepill loop ~10kHz 
  motor.loopFOC();

  // Motion control function
  // velocity, position or voltage (defined in motor.controller)
  // this function can be run at much lower frequency than loopFOC() function
  // You can also use motor.move() and set the motor.target in the code
  motor.move(target_angle);

  // function intended to be used with serial plotter to monitor motor variables
  // significantly slowing the execution down!!!!
  // motor.monitor();
  
  // user communication
  command.run();
}

This is the Serial Comunication:

MOT: Monitor enabled!
MOT: Init
MOT: Monitor enabled!
MOT: Init
MOT: Enable driver.
MOT: Align sensor.
MOT: sensor_direction==CCW
MOT: PP check: fail - estimated pp:141.8528
MOT: Zero elec. angle: 0.88
MOT: No current sense.
MOT: Ready.
Motor ready.

Set the target angle using serial terminal:

#2

Hey @Patrizio_Zaccagnini,

I would highly suggest you to read a bit of the docs before going to the hardware. I know there is a lot ofit, but it will help you to advance faster.

I have a couple of questions:

  • did you do the sensor stand alone test, does it show exactly 6.28 for one full rotation?
  • did you do the open loop test, does the motor turn exactly one rotation when you send it the target 6.28 command?

Finally the amt103 by default have PPR of 2048 and even though they are configurable they can not go any higher, so 8192 is not possible for ant103.

So a quick fix for your problem might be to use 2048 instead of 8192. :slight_smile: