Carbon Fibre / Mbed 2 deprecated Motor_test_harness

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Dependencies:   Classic_PID iC_MU mbed-rtos mbed

TiltVelocityLoop.cpp@2:dc684c402296, 2015-05-27 (annotated)

Committer:
acodd
Date:
Wed May 27 07:13:54 2015 +0000
Revision:
2:dc684c402296
Parent:
0:7ce0bc67f60f
Child:
3:f8a5c1cee1fa
First version of a full control loop for the T3 head

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Who changed what in which revision?

UserRevisionLine numberNew contents of line
ms523 0:7ce0bc67f60f 1 #include "mbed.h"
ms523 0:7ce0bc67f60f 2 #include "iC_MU.h"
ms523 0:7ce0bc67f60f 3 #include "rtos.h"
ms523 0:7ce0bc67f60f 4 #include "Classic_PID.h"
ms523 0:7ce0bc67f60f 5
ms523 0:7ce0bc67f60f 6 // Define limits for zero crossing
ms523 0:7ce0bc67f60f 7 // These values should allow operation upto 3750 RPM
ms523 0:7ce0bc67f60f 8 #define bits 18 // The number of bits we want to use
ms523 0:7ce0bc67f60f 9 #define OneTurn (1<<bits) // 262144 counts per rev
ms523 0:7ce0bc67f60f 10 #define Lower (1<<(bits-5)) // 8192 counts = 11.25 degrees
ms523 0:7ce0bc67f60f 11 #define Upper OneTurn - Lower // 262144 - 8192 = 253952
ms523 0:7ce0bc67f60f 12
acodd 2:dc684c402296 13 extern Serial pc;
ms523 0:7ce0bc67f60f 14 extern iC_MU tilt_ic_mu;
acodd 2:dc684c402296 15 extern iC_MU TiltPos;
ms523 0:7ce0bc67f60f 16 extern PwmOut Tilt_Motor_PWM;
ms523 0:7ce0bc67f60f 17 extern DigitalOut Tilt_Motor_Direction;
ms523 0:7ce0bc67f60f 18 extern Classic_PID TiltVelocityPID;
acodd 2:dc684c402296 19 extern float Demand_Count_Rate;
acodd 2:dc684c402296 20 extern float Tilt_motor_max_count_rate;
acodd 2:dc684c402296 21 extern float Actual_Motor_Speed;
acodd 2:dc684c402296 22
acodd 2:dc684c402296 23 extern float T_Position; // True Tilt Position (Degrees)
acodd 2:dc684c402296 24 extern float T_sf;
acodd 2:dc684c402296 25
ms523 0:7ce0bc67f60f 26
ms523 0:7ce0bc67f60f 27 int LastTiltPosition = 0;
acodd 2:dc684c402296 28 int Position = 0;
acodd 2:dc684c402296 29 int Velocity = 0;
acodd 2:dc684c402296 30 float Duty_Cycle = 0.0;
acodd 2:dc684c402296 31
acodd 2:dc684c402296 32
acodd 2:dc684c402296 33 // S_Ramp Fade values
acodd 2:dc684c402296 34 float MaxSpeed = 60.00; // 5 Deg/s, 1250 RPM
acodd 2:dc684c402296 35 float Tilt_motor_max_count_rate = 5461; //encoder counts / ms
acodd 2:dc684c402296 36
acodd 2:dc684c402296 37 float T_Position = 0; // True Tilt Position (Degrees)
acodd 2:dc684c402296 38 float T_sf = 1456.355; // counts per degree
acodd 2:dc684c402296 39
acodd 2:dc684c402296 40 // Main servo loop
acodd 2:dc684c402296 41 int DoMove = 0;
acodd 2:dc684c402296 42 const float LOOPs = 0.001;
acodd 2:dc684c402296 43 float D = 10; // Fade distance
acodd 2:dc684c402296 44 float T = 15; // Fade time
acodd 2:dc684c402296 45 float dir = 1; //direction flag
acodd 2:dc684c402296 46 float ta; // The actual value used after sanity checks
acodd 2:dc684c402296 47 float ts; // The actual value used after sanity checks(S ramping)
acodd 2:dc684c402296 48 float tsfade = 0.5; // segment time for S ramped fade
acodd 2:dc684c402296 49 float tscut = 0.2; // segment time for S ramped cut
acodd 2:dc684c402296 50 float j; // jerk value for fade
acodd 2:dc684c402296 51 float aj; // accel value when S ramping
acodd 2:dc684c402296 52 float Vp; // Top speed for the move Deg/s @ load (125:1 Ratio to motor)
acodd 2:dc684c402296 53 float Vs; // Speed step increment
acodd 2:dc684c402296 54 float Da; // Accel distance
acodd 2:dc684c402296 55 float Ds; // Distance convered at steady speed
acodd 2:dc684c402296 56 float s; // Profiler internal demand speed (always positive)
acodd 2:dc684c402296 57 float sout; // Demand as applied by the Vff term
acodd 2:dc684c402296 58 float s_profile; // output demand speed to postion loop + or -)
acodd 2:dc684c402296 59 float P; // Profiler Demand postion
acodd 2:dc684c402296 60 float fadetime; // this will retain the current fade time
acodd 2:dc684c402296 61 float Error; // Current position vs the profiler position
acodd 2:dc684c402296 62 float Vff = 1; // Velocity feedforward term - a value of 1 sends 100% profiler speed demand to motor
acodd 2:dc684c402296 63 float T_Kp = 8; // This is is multiplied by the position error and added to the motor demand
acodd 2:dc684c402296 64 float Prop; // The demand created by the Kp and error calculation
acodd 2:dc684c402296 65 float demand = 0; // The value sento to the motor to make it move
acodd 2:dc684c402296 66 float P_vel;
acodd 2:dc684c402296 67 float Va; // mid speed point
acodd 2:dc684c402296 68 float as; // acceleration value during linear accel stage
acodd 2:dc684c402296 69 float Vj; // Speed at bottom intersection
acodd 2:dc684c402296 70 float Vjp; // Speed at top intersection
acodd 2:dc684c402296 71 float c; // constant for up ramp y=mx+c
acodd 2:dc684c402296 72 float b; // constant for down ramp y = mx+b
acodd 2:dc684c402296 73 float real_time;
acodd 2:dc684c402296 74 float fade_tilt;
acodd 2:dc684c402296 75 float joy_tilt;
acodd 2:dc684c402296 76 float fade_time=10;
acodd 2:dc684c402296 77 extern bool joystick;
acodd 2:dc684c402296 78 extern float Time;
acodd 2:dc684c402296 79
acodd 2:dc684c402296 80 float T_Joy = 0.0;
acodd 2:dc684c402296 81
ms523 0:7ce0bc67f60f 82
ms523 0:7ce0bc67f60f 83 void TiltVelocityLoop(void const *args)
ms523 0:7ce0bc67f60f 84 {
acodd 2:dc684c402296 85 T_Position = 360 - (TiltPos.ReadPOSITION()/T_sf); // the 3D printed unit counts the opposite way to the aluminium unit.
acodd 2:dc684c402296 86
acodd 2:dc684c402296 87 if (joystick){
acodd 2:dc684c402296 88 P = T_Position;
acodd 2:dc684c402296 89 }
acodd 2:dc684c402296 90
acodd 2:dc684c402296 91 Position = tilt_ic_mu.ReadPOSITION() >> (19 - bits);// Read the current position from the iC-MU and bitshift to reduce noise
acodd 2:dc684c402296 92 Velocity = Position - LastTiltPosition; // Calculate change in position (i.e. Velocity)
acodd 2:dc684c402296 93 Actual_Motor_Speed = Velocity;
acodd 2:dc684c402296 94
ms523 0:7ce0bc67f60f 95
ms523 0:7ce0bc67f60f 96 // Check to see if we have gone past the index point
ms523 0:7ce0bc67f60f 97 if(Position < Lower & LastTiltPosition > Upper) { // We have gone over the index point in 1 direction
ms523 0:7ce0bc67f60f 98 Velocity += OneTurn;
ms523 0:7ce0bc67f60f 99 } else if(Position > Upper & LastTiltPosition < Lower) {// We have gone over the index point in the other direction
ms523 0:7ce0bc67f60f 100 Velocity -= OneTurn;
acodd 2:dc684c402296 101 }
ms523 0:7ce0bc67f60f 102 LastTiltPosition = Position; // Update new position from next time
ms523 0:7ce0bc67f60f 103
acodd 2:dc684c402296 104 TiltVelocityPID.setProcessValue(Velocity);
acodd 2:dc684c402296 105
acodd 2:dc684c402296 106 if (DoMove == 1) {
acodd 2:dc684c402296 107 if ((fadetime < ts) & (s < Vp)) {
acodd 2:dc684c402296 108 //led2 = 0;
acodd 2:dc684c402296 109 s = (j/2)*fadetime*fadetime; //bottom parabola
acodd 2:dc684c402296 110 fadetime = fadetime + LOOPs; // This provides the base time for the fade sequence
acodd 2:dc684c402296 111 } else if ((fadetime >= ts) & (fadetime <(2*ts))) {
acodd 2:dc684c402296 112 s = (as*fadetime)+c; //steady accel stage
acodd 2:dc684c402296 113 fadetime = fadetime + LOOPs;
acodd 2:dc684c402296 114 } else if ((fadetime >= (2*ts)) & (fadetime <(3*ts))) {
acodd 2:dc684c402296 115 s = (-(j/2)*(fadetime-(3*ts))*(fadetime-(3*ts))) + Vp; // Top parabola
acodd 2:dc684c402296 116 fadetime = fadetime + LOOPs;
acodd 2:dc684c402296 117 } else if ((fadetime >= (3*ts)) & (fadetime <(T-(3*ts)))) {
acodd 2:dc684c402296 118 s = Vp; // Steady Speed Stage
acodd 2:dc684c402296 119 fadetime = fadetime + LOOPs;
acodd 2:dc684c402296 120 } else if ((fadetime >= (T-(3*ts))) & (fadetime <(T-(2*ts)))) {
acodd 2:dc684c402296 121 s = (-(j/2)*(fadetime-(T-(3*ts)))*(fadetime-(T-(3*ts)))) + Vp; // Top parabola down
acodd 2:dc684c402296 122 fadetime = fadetime + LOOPs;
acodd 2:dc684c402296 123 } else if ((fadetime >= (T-ts-ts)) & (fadetime < (T-ts))) {
acodd 2:dc684c402296 124 s = -as*(fadetime - T) + c; //steady decel stage
acodd 2:dc684c402296 125 fadetime = fadetime + LOOPs;
acodd 2:dc684c402296 126 } else if ((fadetime >= (T-ts)) & (s < Vp) & (fadetime <= T)) {
acodd 2:dc684c402296 127 //led2 = 1;
acodd 2:dc684c402296 128 s = (j/2)*(T-fadetime)*(T-fadetime); //bottom parabola to end
acodd 2:dc684c402296 129 fadetime = fadetime + LOOPs;
acodd 2:dc684c402296 130 } else if (fadetime >= T) {
acodd 2:dc684c402296 131 s=0;
acodd 2:dc684c402296 132 //led2 = 0;
acodd 2:dc684c402296 133 DoMove = 0;
acodd 2:dc684c402296 134 TiltVelocityPID.setSetPoint(0);
acodd 2:dc684c402296 135 } else {
acodd 2:dc684c402296 136 fadetime = fadetime + LOOPs; // for TBC reason this is needed!
acodd 2:dc684c402296 137 }
acodd 2:dc684c402296 138 if (DoMove==1) {
acodd 2:dc684c402296 139 // compute the new position demand:
acodd 2:dc684c402296 140 s_profile = s * dir;
acodd 2:dc684c402296 141 P = P + (s_profile * LOOPs);
acodd 2:dc684c402296 142 real_time = ((T - fadetime) * 1000);
acodd 2:dc684c402296 143
acodd 2:dc684c402296 144 sout = s_profile * Vff; //Apply velocity feedforward term
acodd 2:dc684c402296 145 Error = (P - T_Position); // Position Error
acodd 2:dc684c402296 146 Prop = T_Kp * Error; // Calculate proportional gain element
acodd 2:dc684c402296 147 demand = sout + Prop; // Sum the result of Vff and Kp to the demand
acodd 2:dc684c402296 148 //This demand represents degrees/s @ the output shaft.
acodd 2:dc684c402296 149 // Ratio is 125:1. 5461 couns/ms = 60 Deg/s @ output
acodd 2:dc684c402296 150 // scalefactor is approx 91
acodd 2:dc684c402296 151 P_vel = demand * 72.8;
acodd 2:dc684c402296 152 TiltVelocityPID.setSetPoint(P_vel);
acodd 2:dc684c402296 153 //.printf("\n\r %f, %f, %f, %f, %f",Time, s_profile, P_vel, T_Position, Error);
acodd 2:dc684c402296 154 //me = Time + LOOPs;
acodd 2:dc684c402296 155 }
acodd 2:dc684c402296 156 } else {
acodd 2:dc684c402296 157
acodd 2:dc684c402296 158 if(!joystick) {
acodd 2:dc684c402296 159
acodd 2:dc684c402296 160 P = P + (T_Joy * LOOPs);
acodd 2:dc684c402296 161 sout = T_Joy * Vff; //Apply velocity feedforward term
acodd 2:dc684c402296 162 Error = (P - T_Position); // Position Error
acodd 2:dc684c402296 163 Prop = T_Kp * Error; // Calculate proportional gain element
acodd 2:dc684c402296 164 demand = sout + Prop; // Sum the result of Vff and Kp to the demand
acodd 2:dc684c402296 165 //This demand represents degrees/s @ the output shaft.
acodd 2:dc684c402296 166 // Ratio is 125:1. 5461 couns/ms = 60 Deg/s @ output
acodd 2:dc684c402296 167 // scalefactor is approx 91
acodd 2:dc684c402296 168 P_vel = demand * 72.8;
acodd 2:dc684c402296 169 TiltVelocityPID.setSetPoint(P_vel);
acodd 2:dc684c402296 170 }
acodd 2:dc684c402296 171
acodd 2:dc684c402296 172 }
acodd 2:dc684c402296 173
acodd 2:dc684c402296 174 Duty_Cycle = TiltVelocityPID.compute_ff()/Tilt_motor_max_count_rate;
ms523 0:7ce0bc67f60f 175
ms523 0:7ce0bc67f60f 176 if(Duty_Cycle < 0) {
acodd 2:dc684c402296 177 Tilt_Motor_Direction = 1;
ms523 0:7ce0bc67f60f 178 Tilt_Motor_PWM = 1 - (Duty_Cycle * -1.0);
ms523 0:7ce0bc67f60f 179 } else {
acodd 2:dc684c402296 180 Tilt_Motor_Direction = 0;
ms523 0:7ce0bc67f60f 181 Tilt_Motor_PWM = 1 - Duty_Cycle;
ms523 0:7ce0bc67f60f 182 }
acodd 2:dc684c402296 183 }
acodd 2:dc684c402296 184
acodd 2:dc684c402296 185 void Profile() // For S ramped movement using Servo for S ramping
acodd 2:dc684c402296 186 {
acodd 2:dc684c402296 187 if ((fade_tilt >=0) & (fade_tilt <= 359)) {
acodd 2:dc684c402296 188 D = fade_tilt - T_Position; // Calculate distance to move
acodd 2:dc684c402296 189 } else {
acodd 2:dc684c402296 190 D = 0;
acodd 2:dc684c402296 191 abort(); // leave this function
acodd 2:dc684c402296 192 // add an error event handler here
acodd 2:dc684c402296 193 }
acodd 2:dc684c402296 194
acodd 2:dc684c402296 195 if (D <= 0) {
acodd 2:dc684c402296 196 dir = -1;
acodd 2:dc684c402296 197 D = abs(D);
acodd 2:dc684c402296 198 } else {
acodd 2:dc684c402296 199 dir = 1;
acodd 2:dc684c402296 200 }
acodd 2:dc684c402296 201
acodd 2:dc684c402296 202 if (fade_time <= (6*tsfade + 0.2)) {
acodd 2:dc684c402296 203 ts = tscut;
acodd 2:dc684c402296 204 T = fade_time;
acodd 2:dc684c402296 205 } else {
acodd 2:dc684c402296 206 ts = tsfade;
acodd 2:dc684c402296 207 T = fade_time;
acodd 2:dc684c402296 208 }
acodd 2:dc684c402296 209 if (fade_time <= (6*tscut+0.2)) {
acodd 2:dc684c402296 210 T = 6*tscut + 0.2; //min fade fime
acodd 2:dc684c402296 211 }
acodd 2:dc684c402296 212
acodd 2:dc684c402296 213 Vp = D / (T-(3*ts)); // Equation 1
acodd 2:dc684c402296 214 if (Vp > MaxSpeed) { //Check for maximum speed condition
acodd 2:dc684c402296 215 Vp = MaxSpeed; //Do the fade as fast as possible
acodd 2:dc684c402296 216 T = (D + (Vp * (3*ts)))/Vp;
acodd 2:dc684c402296 217 }
acodd 2:dc684c402296 218
acodd 2:dc684c402296 219 // New version based on S-Ramping Doc - V2
acodd 2:dc684c402296 220
acodd 2:dc684c402296 221 j = Vp / (2*ts*ts);
acodd 2:dc684c402296 222 as = j * ts;
acodd 2:dc684c402296 223 c = -(Vp / 4);
acodd 2:dc684c402296 224 s = 0;
acodd 2:dc684c402296 225 fadetime = 0;
acodd 2:dc684c402296 226 // Time = 0;
acodd 2:dc684c402296 227 P = T_Position;
acodd 2:dc684c402296 228
acodd 2:dc684c402296 229 }
acodd 2:dc684c402296 230
acodd 2:dc684c402296 231