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Question SMC using encoder creeps

Discussion in 'Miscellaneous' started by Eli Wizard, Jun 19, 2024.

  1. Eli Wizard

    Eli Wizard New Member

    Joined:
    Jan 22, 2017
    Messages:
    9
    Location:
    Ottawa
    Balance:
    14Coins
    Ratings:
    +1 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    My rig uses encoders on the motors and I'm trying to use SMC.
    I've got an UNO, IBT-2 and a small 12v motor with reduction gearbox and an osepp encoder fitted to motor shaft set up for testing.
    I've got the encoder into the SMC code and:
    -the SMC monitor displays a near perfect overlay of target and feedback
    - the motor appears to be in sync but is advancing (or regressing).
    It did not behave like this using a pot for feedback so I don't think the gears are at fault.
    Instead of keeping a constant sweep of 2 > 5, 5 > 2, 2 > 5,,, it goes something like 2 > 5, 5 > 2, 2 > 6, 6 > 3, 3 > 7,,,
    the encoder is mapped:
    SWmulti = map(SMPulseCount, -512, 512, 0, 1023);

    How may I stop creeping?

    thanks
  2. Eli Wizard

    Eli Wizard New Member

    Joined:
    Jan 22, 2017
    Messages:
    9
    Location:
    Ottawa
    Balance:
    14Coins
    Ratings:
    +1 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    and here's the sketch I'm inserting, I can't post the SMC sketch with it in it (too many characters)

    Code:
    
    
    int SMsensor01;
    int SMsensor02;
    int SWmulti;
    int SMstepOld;
    int SMstep;
    long SMPulseCount;
    #define SMSENSOR_A 2
    #define SMSENSOR_B 3
    
    void checkState(){
      SMsensor01 = digitalRead(SMSENSOR_A);
      SMsensor02 = digitalRead(SMSENSOR_B);
    
      if(SMsensor01 == 1 && SMsensor02 == 1){
        SMstep = 0;
        if(SMstepOld == 1){
          SMPulseCount--;
        }
        if(SMstepOld == 3){
          SMPulseCount++;
        }
        SMstepOld = 0;
      }
    
      if(SMsensor01 == 0 && SMsensor02 == 1){
        SMstep = 1;
        if(SMstepOld == 2){
          SMPulseCount--;
        }
        if(SMstepOld == 0){
          SMPulseCount++;
        }
        SMstepOld = 1;
      }
    
      if(SMsensor01 == 0 && SMsensor02 == 0){
        SMstep = 2;
        if(SMstepOld == 3){
          SMPulseCount--;
        }
        if(SMstepOld == 1){
          SMPulseCount++;
        }
        SMstepOld = 2;
      }
    
      if(SMsensor01 == 1 && SMsensor02 == 0){
        SMstep = 3;
        if(SMstepOld == 0){
          SMPulseCount--;
        }
        if(SMstepOld == 2){
          SMPulseCount++;
        }
        SMstepOld = 3;
      }
    
    }
    
    void setup() {
    
     
    
    
      attachInterrupt(0, checkState, CHANGE);
      attachInterrupt(1, checkState, CHANGE);
      //Serial.begin(9600);
      SMPulseCount = 0;
    }
    
    void loop() {
    
     
     
      if(SMPulseCount > -1){
       
      }
    
      if(SMPulseCount < 10 && SMPulseCount > -10){
    
      }
    
      if(SMPulseCount < 100 && SMPulseCount > -100){
    
      }
    
    
      if(SMsensor01 == 1){
    
      }
      else{
    
      }
    
    
    
      if(SMsensor02 == 1){
    
      }
      else{
    
      }
    
      SWmulti = (SMPulseCount - 850);
      SWmulti = constrain(SWmulti, 0, 45);
     
        Serial.print("SMPulseCount: ");
        Serial.print(SMPulseCount);
        Serial.print("\t");
        Serial.print("SWmulti: ");
        Serial.println(SWmulti);
        //Serial.print("SMPulseCount: ");
        //Serial.println(SMPulseCount);
    }