File content as of revision 2:dc684c402296:

#include "mbed.h"
#include "iC_MU.h"
#include "rtos.h"
#include "Classic_PID.h"

// Define limits for zero crossing
// These values should allow operation upto 3750 RPM
#define bits 18                 // The number of bits we want to use
#define OneTurn (1<<bits)       // 262144 counts per rev
#define Lower (1<<(bits-5))     // 8192 counts = 11.25 degrees
#define Upper OneTurn - Lower   // 262144 - 8192 = 253952

extern Serial pc;
extern iC_MU tilt_ic_mu;
extern iC_MU TiltPos;
extern PwmOut Tilt_Motor_PWM;
extern DigitalOut Tilt_Motor_Direction;
extern Classic_PID TiltVelocityPID;
extern float Demand_Count_Rate;
extern float Tilt_motor_max_count_rate;
extern float Actual_Motor_Speed;

extern float T_Position; // True Tilt Position (Degrees)
extern float T_sf;


int LastTiltPosition = 0;
int Position = 0;
int Velocity = 0;
float Duty_Cycle = 0.0;


// S_Ramp Fade values
float MaxSpeed = 60.00; // 5 Deg/s, 1250 RPM
float Tilt_motor_max_count_rate = 5461; //encoder counts / ms

float T_Position = 0; // True Tilt Position (Degrees)
float T_sf = 1456.355;  // counts per degree

// Main servo loop
int DoMove = 0;
const float LOOPs = 0.001;
float D = 10; // Fade distance
float T = 15; // Fade time
float dir = 1; //direction flag
float ta; // The actual value used after sanity checks
float ts; // The actual value used after sanity checks(S ramping)
float tsfade = 0.5; // segment time for S ramped fade
float tscut = 0.2; // segment time for S ramped cut
float j; // jerk value for fade
float aj; // accel value when S ramping
float Vp;  // Top speed for the move Deg/s @ load (125:1 Ratio to motor)
float Vs;  // Speed step increment
float Da;  // Accel distance
float Ds; // Distance convered at steady speed
float s;  // Profiler internal demand speed (always positive)
float sout;  // Demand as applied by the Vff term
float s_profile; // output demand speed to postion loop + or -)
float P;  // Profiler Demand postion
float fadetime; // this will retain the current fade time
float Error;    // Current position vs the profiler position
float Vff = 1;  // Velocity feedforward term - a value of 1 sends 100% profiler speed demand to motor
float T_Kp = 8;  //  This is is multiplied by the position error and added to the motor demand
float Prop;   // The demand created by the Kp and error calculation
float demand = 0;  // The value sento to the motor to make it move
float P_vel;
float Va; // mid speed point
float as; // acceleration value during linear accel stage
float Vj; // Speed at bottom intersection
float Vjp; // Speed at top intersection
float c; // constant for up ramp y=mx+c
float b; // constant for down ramp y = mx+b
float real_time;
float fade_tilt;
float joy_tilt;
float fade_time=10;
extern bool joystick;
extern float Time;

float T_Joy = 0.0;


void TiltVelocityLoop(void const *args)
{
    T_Position = 360 - (TiltPos.ReadPOSITION()/T_sf); // the 3D printed unit counts the opposite way to the aluminium unit.
    
    if (joystick){
        P = T_Position;
        }
    
    Position = tilt_ic_mu.ReadPOSITION() >> (19 - bits);// Read the current position from the iC-MU and bitshift to reduce noise
    Velocity = Position - LastTiltPosition;             // Calculate change in position (i.e. Velocity)
    Actual_Motor_Speed = Velocity;


    // Check to see if we have gone past the index point
    if(Position < Lower & LastTiltPosition > Upper) {       // We have gone over the index point in 1 direction
        Velocity += OneTurn;
    } else if(Position > Upper & LastTiltPosition < Lower) {// We have gone over the index point in the other direction
        Velocity -= OneTurn;
    }
    LastTiltPosition = Position;                            // Update new position from next time

    TiltVelocityPID.setProcessValue(Velocity);

    if (DoMove == 1) {
        if ((fadetime < ts) & (s < Vp)) {
            //led2 = 0;
            s = (j/2)*fadetime*fadetime;  //bottom parabola
            fadetime = fadetime + LOOPs; // This provides the base time for the fade sequence
        } else if ((fadetime >= ts) & (fadetime <(2*ts))) {
            s = (as*fadetime)+c; //steady accel stage
            fadetime = fadetime + LOOPs;
        } else if ((fadetime >= (2*ts)) & (fadetime <(3*ts))) {
            s = (-(j/2)*(fadetime-(3*ts))*(fadetime-(3*ts))) + Vp; // Top parabola
            fadetime = fadetime + LOOPs;
        } else if ((fadetime >= (3*ts)) & (fadetime <(T-(3*ts)))) {
            s = Vp;  // Steady Speed Stage
            fadetime = fadetime + LOOPs;
        } else if ((fadetime >= (T-(3*ts))) & (fadetime <(T-(2*ts)))) {
            s = (-(j/2)*(fadetime-(T-(3*ts)))*(fadetime-(T-(3*ts)))) + Vp; // Top parabola down
            fadetime = fadetime + LOOPs;
        } else if ((fadetime >= (T-ts-ts)) & (fadetime < (T-ts))) {
            s = -as*(fadetime - T) + c; //steady decel stage
            fadetime = fadetime + LOOPs;
        } else if ((fadetime >= (T-ts)) & (s < Vp) & (fadetime <= T)) {
            //led2 = 1;
            s = (j/2)*(T-fadetime)*(T-fadetime);  //bottom parabola to end
            fadetime = fadetime + LOOPs;
        } else if (fadetime >= T) {
            s=0;
            //led2 = 0;
            DoMove = 0;
            TiltVelocityPID.setSetPoint(0);
        } else {
            fadetime = fadetime + LOOPs; // for TBC reason this is needed!
        }
        if (DoMove==1) {
            // compute the new position demand:
            s_profile = s * dir;
            P = P + (s_profile * LOOPs);
            real_time = ((T - fadetime) * 1000);

            sout = s_profile * Vff;  //Apply velocity feedforward term
            Error = (P - T_Position);    // Position Error
            Prop = T_Kp * Error;      // Calculate proportional gain element
            demand = sout + Prop;   // Sum the result of Vff and Kp to the demand
            //This demand represents degrees/s @ the output shaft.
            // Ratio is 125:1.  5461 couns/ms = 60 Deg/s @ output
            // scalefactor is approx 91
            P_vel = demand * 72.8;
            TiltVelocityPID.setSetPoint(P_vel);
            //.printf("\n\r %f,   %f,   %f,   %f, %f",Time, s_profile, P_vel, T_Position, Error);
            //me = Time + LOOPs;
        }
    } else {

        if(!joystick) {

            P = P + (T_Joy * LOOPs);
            sout = T_Joy * Vff;  //Apply velocity feedforward term
            Error = (P - T_Position);    // Position Error
            Prop = T_Kp * Error;      // Calculate proportional gain element
            demand = sout + Prop;   // Sum the result of Vff and Kp to the demand
            //This demand represents degrees/s @ the output shaft.
            // Ratio is 125:1.  5461 couns/ms = 60 Deg/s @ output
            // scalefactor is approx 91
            P_vel = demand * 72.8;
            TiltVelocityPID.setSetPoint(P_vel);
        }

    }

    Duty_Cycle = TiltVelocityPID.compute_ff()/Tilt_motor_max_count_rate;

    if(Duty_Cycle < 0) {
        Tilt_Motor_Direction = 1;
        Tilt_Motor_PWM = 1 - (Duty_Cycle * -1.0);
    } else {
        Tilt_Motor_Direction = 0;
        Tilt_Motor_PWM = 1 - Duty_Cycle;
    }
}

void Profile() // For S ramped movement using Servo for S ramping
{
    if ((fade_tilt >=0) & (fade_tilt <= 359)) {
        D = fade_tilt - T_Position; // Calculate distance to move
    } else {
        D = 0;
        abort();  // leave this function
        // add an error event handler here
    }

    if (D <= 0) {
        dir = -1;
        D = abs(D);
    } else {
        dir = 1;
    }

    if (fade_time <= (6*tsfade + 0.2)) {
        ts = tscut;
        T = fade_time;
    } else {
        ts = tsfade;
        T = fade_time;
    }
    if (fade_time <= (6*tscut+0.2)) {
        T = 6*tscut + 0.2;  //min fade fime
    }

    Vp = D / (T-(3*ts));  // Equation 1
    if (Vp > MaxSpeed) {         //Check for maximum speed condition
        Vp = MaxSpeed;           //Do the fade as fast as possible
        T = (D + (Vp * (3*ts)))/Vp;
    }

    // New version based on S-Ramping Doc - V2

    j = Vp / (2*ts*ts);
    as = j * ts;
    c = -(Vp / 4);
    s = 0;
    fadetime = 0;
   // Time = 0;
    P = T_Position;

}