File content as of revision 8:935abf8ecc27:

#include "mbed.h"
#include <math.h>
#include "MODSERIAL.h"
#include "QEI.h"
#include "HIDScope.h"
#include "BiQuad.h"

//set pins
DigitalIn encoder1A (D13); //Channel A van Encoder 1
DigitalIn encoder1B (D12); //Channel B van Encoder 1
DigitalOut led1 (D11); 
DigitalOut led2 (D10);
AnalogIn potMeter1(A2);
AnalogIn potMeter2(A1);
DigitalOut motor1DirectionPin(D7);
PwmOut motor1MagnitudePin(D6);
DigitalOut motor2DirectionPin(D4);
PwmOut motor2MagnitudePin(D5);
DigitalIn button1(D8);
DigitalIn button2(D9);

//library settings
Serial pc(USBTX,USBRX);
Ticker MeasureTicker, BiQuadTicker; //, TimeTracker; // sampleT;
HIDScope    scope(3);

//set initial conditions
float error1_prev = 0;
float error2_prev = 0;
float IntError1 = 0;
float IntError2 = 0;
float q1 = 0;
float q2 = 0;
float q1_dot;
float q2_dot;

//set constant or variable values
int counts1 = 0;
int counts2 = 0;
int counts1Prev = 0;
int counts2Prev = 0;
double DerivativeCounts;
float x0 = 1.0;
float L0 = 1.0;
float L1 = 1.0;
float dx;
float dy;
float dy_stampdown = 0.05; //5 cm movement downward to stamp

float t_sample = 0.01; //seconds
float referenceVelocity = 0;
float bqcDerivativeCounts = 0;
const float PI = 3.141592653589793;
const int cw = 0;       //values for cw and ccw are inverted!! cw=0 and ccw=1
const int ccw = 1;

//set BiQuad
BiQuadChain bqc;
BiQuad bq1(0.0186,    0.0743,    0.1114,    0.0743,    0.0186); //get numbers from butter filter MATLAB
BiQuad bq2(1.0000,   -1.5704,    1.2756,   -0.4844,    0.0762);

//set go-Ticker settings
volatile bool MeasureTicker_go=false, BiQuadTicker_go=false, FeedbackTicker_go=false, TimeTracker_go=false; // sampleT_go=false;
void MeasureTicker_act(){MeasureTicker_go=true;}; // Activates go-flags
void BiQuadTicker_act(){BiQuadTicker_go=true;};
void FeedbackTicker_act(){FeedbackTicker_go=true;};
void TimeTracker_act(){TimeTracker_go=true;};
//void sampleT_act(){sampleT_go=true;};

//define encoder counts and degrees
QEI Encoder1(D12, D13, NC, 32); // turns on encoder
QEI Encoder2(D14, D15, NC, 32); // turns on encoder
const int counts_per_revolution = 4200; //counts per motor axis revolution
const int inverse_gear_ratio = 131;
//const float motor_axial_resolution = counts_per_revolution/(2*PI);
const float resolution = counts_per_revolution/(2*PI/inverse_gear_ratio);  //87567.0496892 counts per radian, encoder axis

float GetReferenceKinematics1(){
    
    //get joint positions q from encoder
    float Encoder1Position = counts1/resolution;         //position in radians, encoder axis
    float q1 = Encoder1Position*inverse_gear_ratio;        //position in radians, motor axis
    
    //float Encoder2Position = counts2/resolution;         //position in radians, encoder axis
    //float q2 = Encoder2Position*inverse_gear_ratio;        //position in radians, motor axis
    
    //NOTNECESSARY calculate end effector position with Brockett
    
    //NOTNECESSARY get desired position Pe* from EMG(?) 
    
    //get velocity vector v = (Pe*- Pe) = [0; dx; dy] from EMG  
    float biceps1 = button1.read();
    float biceps2 = button2.read();
    if (biceps1 > 0 && biceps2 > 0){
        //both arms activated: stamp moves down
        dx = 0;
        dy = dy_stampdown; //into stamping vertical position?? ~the stamp down action
         wait(1);
        dy = -(dy_stampdown);  //reset vertical position
        }
    else if (biceps1 > 0 && biceps2 <= 0){
        //arm 1 activated, move left
        dx = -biceps1;
        dy = 0;
        }
    else if (biceps1 <= 0 && biceps2 > 0){
        //arm 1 activated, move left
        dx = biceps2;
        dy = 0;
        }
    else{
        dx=0;
        dy=0;
        }
            
    //get joint angles change q_dot = Jpseudo * TwistEndEff  (Matlab)
    float q1_dot = dy*(((x0 + L1*cos(q1))*(L0*L0 + L1*sin(q1)*L0 + x0*x0 + L1*cos(q1)*x0 + 1))/(pow(L1*cos(q1),2) + pow(L1*sin(q1),2) + pow(L1*x0*sin(q1),2) + pow(L0*L1*cos(q1),2) - 2*L0*L1*L1*x0*cos(q1)*sin(q1)) - (x0*(pow(L1*cos(q1),2) + pow(L1*sin(q1),2) + L0*L0 + x0*x0 + 2*L0*L1*sin(q1) + 2*L1*x0*cos(q1) + 1))/(pow(L1*cos(q1),2) + pow(L1*sin(q1),2) + pow(L1*x0*sin(q1),2) + pow(L0*L1*cos(q1),2) - 2*L0*L1*L1*x0*cos(q1)*sin(q1))) - dx*(((L0 + L1*sin(q1))*(L0*L0 + L1*sin(q1)*L0 + x0*x0 + L1*cos(q1)*x0 + 1))/(pow(L1*cos(q1),2) + pow(L1*sin(q1),2) + pow(L1*x0*sin(q1),2) + pow(L0*L1*cos(q1),2) - 2*L0*L1*L1*x0*cos(q1)*sin(q1)) - (L0*(pow(L1*cos(q1),2) + pow(L1*sin(q1),2) + L0*L0 + x0*x0 + 2*L0*L1*sin(q1) + 2*L1*x0*cos(q1) + 1))/(pow(L1*cos(q1),2) + pow(L1*sin(q1),2) + pow(L1*x0*sin(q1),2) + pow(L0*L1*cos(q1),2) - 2*L0*L1*L1*x0*cos(q1)*sin(q1)));

    //update joint angles
    q1 = q1 + q1_dot;
    return q1_dot;
    }

float GetReferenceKinematics2(){
    
    //get joint positions q from encoder
    float Encoder1Position = counts1/resolution;         //position in radians, encoder axis
    float q1 = Encoder1Position*inverse_gear_ratio;        //position in radians, motor axis
    
    float Encoder2Position = counts2/resolution;         //position in radians, encoder axis
    float q2 = Encoder2Position*inverse_gear_ratio;        //position in radians, motor axis
    
    //NOTNECESSARY calculate end effector position with Brockett
    
    //NOTNECESSARY get desired position Pe* from EMG(?) 
    
    //get velocity vector v = (Pe*- Pe) = [0; dx; dy] from EMG  
    float biceps1 = button1.read();
    float biceps2 = button2.read();
    while (biceps1 > 0){
        if (biceps2 > 0){ //both arms activated: stamp moves down
            dx = 0;
            dy = dy_stampdown; //into stamping vertical position?? ~the stamp down action
            wait(1);
            dy = -(dy_stampdown);  //reset vertical position
            }
            else{           //left arm activated
            dx = biceps1;
            dy = 0;
            }
    while (biceps2 > 0){
        if (biceps1 <= 0){  //right arm activated
            dx = -biceps2;
            dy = 0;
            } 
            }
    
        //get joint angles change q_dot = Jpseudo * TwistEndEff;  (Matlab)
    float q2_dot = dy*((x0*(L0*L0 + L1*sin(q1)*L0 + x0*x0 + L1*cos(q1)*x0 + 1))/(L1*L1*pow(cos(q1),2) + pow(L1*sin(q1),2) + pow(L1*x0*sin(q1),2) + pow(L0*L1*cos(q1),2) - 2*L0*pow(L1,2)*x0*cos(q1)*sin(q1)) - ((x0 + L1*cos(q1))*(pow(L0,2) + pow(x0,2) + 1))/(pow(L1*cos(q1),2)) + pow(L1*sin(q1),2) + pow(L1*x0*sin(q1),2) + pow(L0*L1*cos(q1),2) - 2*L0*pow(L1,2)*x0*cos(q1)*sin(q1)) - dx*((L0*(L0*L0+L1*sin(q1)*L0+x0*x0+L1*cos(q1)*x0+1))/(pow(L1*cos(q1),2)+pow(L1*sin(q1),2)+pow(L1*x0*sin(q1),2)+pow(L0*L1*cos(q1),2)-2*L0*L1*L1*x0*cos(q1)*sin(q1))-((L0 + L1*sin(q1))*(L0*L0 + x0*x0 + 1))/(pow(L1*cos(q1),2)+pow(L1*sin(q1),2)+pow(L1*x0*sin(q1),2)+pow(L0*L1*cos(q1),2)-2*L0*L1*L1*x0*cos(q1)*sin(q1)));
    
    //update joint angles
    q2 = q2 + q2_dot;
    }
    return q2_dot;
    }

/*
float GetReferencePosition(){
    // Returns reference position in rad. 
    // Positive value means clockwise rotation.
    const float maxPosition = 2*PI; //6.283185307179586; // in radians
    float Potmeter1 = potMeter1.read();
    float referencePosition1 = Potmeter1 * maxPosition; //Potmeter1 * maxPosition; //refpos in radians 
    pc.printf("Max Position: %f rad \r\n", maxPosition);
    pc.printf("Potmeter1, refpos: %f \r\n", Potmeter1);
    pc.printf("Motor Axis Ref Position1: %f rad \r\n", referencePosition1);
    return referencePosition1;
}
*/

float FeedForwardControl1(float q1_dot){
    //float Encoder1Position = counts1/resolution;         //position in radians, encoder axis
    //float Position1 = Encoder1Position*inverse_gear_ratio;        //position in radians, motor axis
    
    // linear feedback control
    float error1 = q1_dot; //referencePosition1 - Position1;             // proportional error in radians
    float Kp = 1; //potMeter2.read();

    float IntError1 = IntError1 + error1*t_sample;             // integrated error in radians
    //float maxKi = 0.2;
    float Ki = 0.1; //potMeter2.read();
    
    float DerivativeError1 = (error1_prev + error1)/t_sample;  // derivative of error in radians
    //float maxKd = 0.2;
    float Kd = 0.0; //potMeter2.read();
    
    //scope.set(0,referencePosition1);
    //scope.set(1,Position1);
    //scope.set(2,Ki);
    //scope.send();
    
    float motorValue1 = error1 * Kp + IntError1 * Ki + DerivativeError1 * Kd;    //total controller output = motor input
    //pc.printf("Motor Axis Position: %f rad \r\n", Position1);
    //pc.printf("Counts encoder1: %i rad \r\n", counts1);
    //pc.printf("Kp: %f \r\n", Kp);
    //pc.printf("MotorValue: %f \r\n", motorValue1);
    
    error1_prev = error1;
    return motorValue1;
}

float FeedForwardControl2(float q2_dot){
    //float Encoder2Position = counts2/resolution;         //position in radians, encoder axis
    //float Position2 = Encoder2Position*inverse_gear_ratio;        //position in radians, motor axis
    
    // linear feedback control
    float error2 = q2_dot; //referencePosition2 - Position2;             // proportional error in radians
    float Kp = 1; //potMeter2.read();

    float IntError2 = IntError2 + error2*t_sample;             // integrated error in radians
    //float maxKi = 0.2;
    float Ki = 0.1; //potMeter2.read();
    
    float DerivativeError2 = (error2_prev + error2)/t_sample;  // derivative of error in radians
    //float maxKd = 0.2;
    float Kd = 0.0; //potMeter2.read()*maxKd;
    
    //scope.set(0,referencePosition1);
    //scope.set(1,Position1);
    //scope.set(2,Ki);
    //scope.send();
    
    float motorValue2 = error2 * Kp + IntError2 * Ki + DerivativeError2 * Kd;    //total controller output = motor input
    //pc.printf("Motor Axis Position: %f rad \r\n", Position1);
    //pc.printf("Counts encoder1: %i rad \r\n", counts1);
    //pc.printf("Kp: %f \r\n", Kp);
    //pc.printf("MotorValue: %f \r\n", motorValue1);
    
    error2_prev = error2;
    return motorValue2;
}

void SetMotor1(float motorValue1)
{
    // Given -1<=motorValue<=1, this sets the PWM and direction
    // bits for motor 1. Positive value makes motor rotating
    // clockwise. motorValues outside range are truncated to
    // within range
    if (motorValue1 >=0) 
        {motor1DirectionPin=cw;
        led1=1;
        led2=0;
        }
    else {motor1DirectionPin=ccw;
        led1=0;
        led2=1;
        }
    if (fabs(motorValue1)>1) motor1MagnitudePin = 1;
        else motor1MagnitudePin = fabs(motorValue1);
}

void SetMotor2(float motorValue2)
{
    // Given -1<=motorValue<=1, this sets the PWM and direction
    // bits for motor 1. Positive value makes motor rotating
    // clockwise. motorValues outside range are truncated to
    // within range
    if (motorValue2 >=0) 
        {motor2DirectionPin=cw;
        led1=1;
        led2=0;
        }
    else {motor2DirectionPin=ccw;
        led1=0;
        led2=1;
        }
    if (fabs(motorValue2)>1) motor2MagnitudePin = 1;
        else motor2MagnitudePin = fabs(motorValue2);
}

void MeasureAndControl()
{
    // This function measures the potmeter position, extracts a
    // reference position from it, and controls the motor with 
    // a Feedback controller. Call this from a Ticker.
    float referencePosition1 = GetReferenceKinematics1();
    float referencePosition2 = GetReferenceKinematics2();
    //float referencePosition1 = GetReferencePosition1();
    //float referencePosition2 = GetReferencePosition2();
    float motorValue1 = FeedForwardControl1(referencePosition1);
    float motorValue2 = FeedForwardControl2(referencePosition2);
    SetMotor1(motorValue1);
    SetMotor2(motorValue2);
}

void TimeTrackerF(){
     //wait(1);   
     //float Potmeter1 = potMeter1.read();
     //float referencePosition1 = GetReferencePosition();
     //pc.printf("TTReference Position: %d rad \r\n", referencePosition1);
     //pc.printf("TTPotmeter1, for refpos: %f \r\n", Potmeter1);
     //pc.printf("TTPotmeter2, Kp: %f \r\n", Potmeter2);
     //pc.printf("TTCounts: %i \r\n", counts1);
}

/*
void BiQuadFilter(){            //this function creates a BiQuad filter for the DerivativeCounts
    //double in=DerivativeCounts();
    bqcDerivativeCounts=bqc.step(DerivativeCounts);
    //return(bqcDerivativeCounts);
    }
  */  

int main()
{
 //Initialize
 led1=1;
 led2=1;
 pc.baud(115200);
 pc.printf("Test putty");
 MeasureTicker.attach(&MeasureTicker_act, 0.01f); 
 bqc.add(&bq1).add(&bq2);
 QEI Encoder(D12, D13, NC, 32); // turns on encoder
 
 while(1)
    {
        if (MeasureTicker_go){
            MeasureTicker_go=false;
            MeasureAndControl();
            counts1 = Encoder1.getPulses();           // gives position of encoder 
            counts2 = Encoder2.getPulses();           // gives position of encoder 
            pc.printf("Resolution: %f pulses/rad \r\n",resolution);
            }
/*
        if (BiQuadTicker_go){
            BiQuadTicker_go=false;
            BiQuadFilter();
        }
*/    
    }
}