File content as of revision 15:d88f10b3b5f8:

#include "Dynamics.h"
#include <math.h>
# define M_PI           3.14159265358979323846

float calcTau(volatile float z[4], float p[10], Gains *gains, Target *target, Serial *pc){
    
    float th1 = z[0];
    float th2 = z[1];
    float dth1 = z[2];
    float dth2 = z[3];
    
    float A[2][2];
    getMassMatrix(A, z, p);
    float AHat = A[1][1]-A[1][0]*A[0][1]/A[0][0];
    
    float corrCentripComp[2];
    getCoriolisCentrip(corrCentripComp, z, p);
    float corrCentripCompHat = corrCentripComp[1]-A[1][0]*corrCentripComp[0]/A[0][0];
    
    float gravityComp[2];
    getGravity(gravityComp, z, p);
    float gravityCompHat = gravityComp[1]-A[1][0]*gravityComp[0]/A[0][0];
    
    float K = gains->getSwingUpK();
    float D = gains->getSwingUpD();
    
    float force;
    if (getEnergy(z, p) > target->getTargetEnergy()) {
        float th2Des = target->getTheta2ForTarget(z);
        force = K*(th2Des - th2) - D*dth2;
    } else {
        float softLimit = 1.5;//2.5;//143 degrees
        float th2Des = thetaDesiredForSwingUp(-softLimit, softLimit, z);
        th2Des = obstacleAvoidance(z, p, th2Des);
        force = K*(th2Des - th2) - D*dth2;
    }

    return force;// + corrCentripCompHat + gravityCompHat;//gains->getDesiredThetaP()*AHat*
}

float obstacleAvoidance(volatile float z[4], float p[10], float theta){
    
    float armLength = p[0];
    float latticePitch = p[9];
    
    float safeRad = 0.07;
    float th2MinMin = M_PI-2.0*asin((latticePitch-safeRad)/(2.0*armLength));
    float th2MinMax = M_PI-2.0*asin((latticePitch*sqrt(2.0)-safeRad)/(2.0*armLength));
    
    float th2MinAvg = (th2MinMin+th2MinMax)/2.0;
    float th2MinAmp = (th2MinMin-th2MinAvg)/2.0;
    
    float th1 = z[0];
    float th2 = z[1];
    
    float direction = 1;
    if (th2<0) direction = -1;
    
    float th2MinPhase = direction*th2MinMin;
    float th2Min = th2MinMin+th2MinAmp*cos(4.0*(th1+th2MinPhase));
    
    if (direction*theta < th2Min) return direction*th2Min;
    return theta;
}

float thetaDesiredForSwingUp(float rangeMin, float rangeMax, volatile float z[4]){
    
    float th1 = z[0];
    float dth1 = z[2];
    
    int numTurns = fix(th1/(2*M_PI));
    float th1Rel = th1-numTurns*2*M_PI;
    
    if (dth1<0) return rangeMin*abs(cos(th1Rel/2.0));//-abs(th1Rel));//*cos(th1)
    return rangeMax*abs(cos(th1Rel/2.0));
}

int fix(float val){//round toward zero
    return val > 0 ? floor(val) : ceil(val);
}