zebra / Mbed 2 deprecated ZebraJointController

zebra joint controller firmware (originally from MIT HKC motor controller by benkatz)

Dependencies:   mbed FastPWM3

Calibration/calibration.cpp@45:26801179208e, 2018-06-27 (annotated)

Committer:
benkatz
Date:
Wed Jun 27 03:44:44 2018 +0000
Revision:
45:26801179208e
Parent:
44:8040fa2fcb0d
Child:
46:2d4b1dafcfe3
Lots of changes, seems to have broken calibration

Who changed what in which revision?

UserRevisionLine numberNew contents of line
benkatz 22:60276ba87ac6 1 /// Calibration procedures for determining position sensor offset,
benkatz 22:60276ba87ac6 2 /// phase ordering, and position sensor linearization
benkatz 22:60276ba87ac6 3 ///
benkatz 22:60276ba87ac6 4
benkatz 22:60276ba87ac6 5 #include "calibration.h"
benkatz 23:2adf23ee0305 6 #include "foc.h"
benkatz 23:2adf23ee0305 7 #include "PreferenceWriter.h"
benkatz 23:2adf23ee0305 8 #include "user_config.h"
benkatz 44:8040fa2fcb0d 9 #include "motor_config.h"
benkatz 44:8040fa2fcb0d 10 #include "current_controller_config.h"
benkatz 22:60276ba87ac6 11
benkatz 23:2adf23ee0305 12 void order_phases(PositionSensor *ps, GPIOStruct *gpio, ControllerStruct *controller, PreferenceWriter *prefs){
benkatz 28:8c7e29f719c5 13
benkatz 22:60276ba87ac6 14 ///Checks phase order, to ensure that positive Q current produces
benkatz 22:60276ba87ac6 15 ///torque in the positive direction wrt the position sensor.
benkatz 22:60276ba87ac6 16 printf("\n\r Checking phase ordering\n\r");
benkatz 22:60276ba87ac6 17 float theta_ref = 0;
benkatz 22:60276ba87ac6 18 float theta_actual = 0;
benkatz 45:26801179208e 19 float v_d = .05f; //Put all volts on the D-Axis
benkatz 44:8040fa2fcb0d 20 float v_q = 0.0f;
benkatz 22:60276ba87ac6 21 float v_u, v_v, v_w = 0;
benkatz 44:8040fa2fcb0d 22 float dtc_u, dtc_v, dtc_w = .5f;
benkatz 22:60276ba87ac6 23 int sample_counter = 0;
benkatz 22:60276ba87ac6 24
benkatz 22:60276ba87ac6 25 ///Set voltage angle to zero, wait for rotor position to settle
benkatz 25:f5741040c4bb 26 abc(theta_ref, v_d, v_q, &v_u, &v_v, &v_w); //inverse dq0 transform on voltages
benkatz 25:f5741040c4bb 27 svm(1.0, v_u, v_v, v_w, &dtc_u, &dtc_v, &dtc_w); //space vector modulation
benkatz 22:60276ba87ac6 28 for(int i = 0; i<20000; i++){
benkatz 27:501fee691e0e 29 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f-dtc_u); // Set duty cycles
benkatz 27:501fee691e0e 30 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_v);
benkatz 27:501fee691e0e 31 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_w);
benkatz 22:60276ba87ac6 32 wait_us(100);
benkatz 22:60276ba87ac6 33 }
benkatz 22:60276ba87ac6 34 //ps->ZeroPosition();
benkatz 22:60276ba87ac6 35 ps->Sample();
benkatz 23:2adf23ee0305 36 wait_us(1000);
benkatz 38:67e4e1453a4b 37 //float theta_start = ps->GetMechPositionFixed(); //get initial rotor position
benkatz 26:2b865c00d7e9 38 float theta_start;
benkatz 23:2adf23ee0305 39 controller->i_b = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset); //Calculate phase currents from ADC readings
benkatz 23:2adf23ee0305 40 controller->i_c = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset);
benkatz 23:2adf23ee0305 41 controller->i_a = -controller->i_b - controller->i_c;
benkatz 23:2adf23ee0305 42 dq0(controller->theta_elec, controller->i_a, controller->i_b, controller->i_c, &controller->i_d, &controller->i_q); //dq0 transform on currents
benkatz 23:2adf23ee0305 43 float current = sqrt(pow(controller->i_d, 2) + pow(controller->i_q, 2));
benkatz 23:2adf23ee0305 44 printf("\n\rCurrent\n\r");
benkatz 23:2adf23ee0305 45 printf("%f %f %f\n\r\n\r", controller->i_d, controller->i_q, current);
benkatz 22:60276ba87ac6 46 /// Rotate voltage angle
benkatz 25:f5741040c4bb 47 while(theta_ref < 4*PI){ //rotate for 2 electrical cycles
benkatz 25:f5741040c4bb 48 abc(theta_ref, v_d, v_q, &v_u, &v_v, &v_w); //inverse dq0 transform on voltages
benkatz 25:f5741040c4bb 49 svm(1.0, v_u, v_v, v_w, &dtc_u, &dtc_v, &dtc_w); //space vector modulation
benkatz 22:60276ba87ac6 50 wait_us(100);
benkatz 27:501fee691e0e 51 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f-dtc_u); //Set duty cycles
benkatz 27:501fee691e0e 52 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_v);
benkatz 27:501fee691e0e 53 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_w);
benkatz 25:f5741040c4bb 54 ps->Sample(); //sample position sensor
benkatz 38:67e4e1453a4b 55 theta_actual = ps->GetMechPositionFixed();
benkatz 26:2b865c00d7e9 56 if(theta_ref==0){theta_start = theta_actual;}
benkatz 22:60276ba87ac6 57 if(sample_counter > 200){
benkatz 22:60276ba87ac6 58 sample_counter = 0 ;
benkatz 22:60276ba87ac6 59 printf("%.4f %.4f\n\r", theta_ref/(NPP), theta_actual);
benkatz 22:60276ba87ac6 60 }
benkatz 22:60276ba87ac6 61 sample_counter++;
benkatz 22:60276ba87ac6 62 theta_ref += 0.001f;
benkatz 22:60276ba87ac6 63 }
benkatz 38:67e4e1453a4b 64 float theta_end = ps->GetMechPositionFixed();
benkatz 22:60276ba87ac6 65 int direction = (theta_end - theta_start)>0;
benkatz 22:60276ba87ac6 66 printf("Theta Start: %f Theta End: %f\n\r", theta_start, theta_end);
benkatz 22:60276ba87ac6 67 printf("Direction: %d\n\r", direction);
benkatz 23:2adf23ee0305 68 if(direction){printf("Phasing correct\n\r");}
benkatz 22:60276ba87ac6 69 else if(!direction){printf("Phasing incorrect. Swapping phases V and W\n\r");}
benkatz 23:2adf23ee0305 70 PHASE_ORDER = direction;
benkatz 22:60276ba87ac6 71 }
benkatz 22:60276ba87ac6 72
benkatz 22:60276ba87ac6 73
benkatz 23:2adf23ee0305 74 void calibrate(PositionSensor *ps, GPIOStruct *gpio, ControllerStruct *controller, PreferenceWriter *prefs){
benkatz 22:60276ba87ac6 75 /// Measures the electrical angle offset of the position sensor
benkatz 22:60276ba87ac6 76 /// and (in the future) corrects nonlinearity due to position sensor eccentricity
benkatz 22:60276ba87ac6 77 printf("Starting calibration procedure\n\r");
benkatz 22:60276ba87ac6 78
benkatz 25:f5741040c4bb 79 const int n = 128*NPP; // number of positions to be sampled per mechanical rotation. Multiple of NPP for filtering reasons (see later)
benkatz 25:f5741040c4bb 80 const int n2 = 50; // increments between saved samples (for smoothing motion)
benkatz 25:f5741040c4bb 81 float delta = 2*PI*NPP/(n*n2); // change in angle between samples
benkatz 25:f5741040c4bb 82 float error_f[n] = {0}; // error vector rotating forwards
benkatz 25:f5741040c4bb 83 float error_b[n] = {0}; // error vector rotating backwards
benkatz 28:8c7e29f719c5 84 const int n_lut = 128;
benkatz 28:8c7e29f719c5 85 int lut[n_lut]= {0}; // clear any old lookup table before starting.
benkatz 28:8c7e29f719c5 86 ps->WriteLUT(lut);
benkatz 22:60276ba87ac6 87 int raw_f[n] = {0};
benkatz 22:60276ba87ac6 88 int raw_b[n] = {0};
benkatz 22:60276ba87ac6 89 float theta_ref = 0;
benkatz 22:60276ba87ac6 90 float theta_actual = 0;
benkatz 45:26801179208e 91 float v_d = .05f; // Put volts on the D-Axis
benkatz 44:8040fa2fcb0d 92 float v_q = 0.0f;
benkatz 22:60276ba87ac6 93 float v_u, v_v, v_w = 0;
benkatz 44:8040fa2fcb0d 94 float dtc_u, dtc_v, dtc_w = .5f;
benkatz 22:60276ba87ac6 95
benkatz 22:60276ba87ac6 96
benkatz 22:60276ba87ac6 97 ///Set voltage angle to zero, wait for rotor position to settle
benkatz 25:f5741040c4bb 98 abc(theta_ref, v_d, v_q, &v_u, &v_v, &v_w); // inverse dq0 transform on voltages
benkatz 25:f5741040c4bb 99 svm(1.0, v_u, v_v, v_w, &dtc_u, &dtc_v, &dtc_w); // space vector modulation
benkatz 22:60276ba87ac6 100 for(int i = 0; i<40000; i++){
benkatz 27:501fee691e0e 101 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f-dtc_u); // Set duty cycles
benkatz 24:58c2d7571207 102 if(PHASE_ORDER){
benkatz 27:501fee691e0e 103 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_v);
benkatz 27:501fee691e0e 104 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_w);
benkatz 22:60276ba87ac6 105 }
benkatz 22:60276ba87ac6 106 else{
benkatz 27:501fee691e0e 107 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_v);
benkatz 27:501fee691e0e 108 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_w);
benkatz 22:60276ba87ac6 109 }
benkatz 22:60276ba87ac6 110 wait_us(100);
benkatz 22:60276ba87ac6 111 }
benkatz 22:60276ba87ac6 112 ps->Sample();
benkatz 23:2adf23ee0305 113 controller->i_b = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset); //Calculate phase currents from ADC readings
benkatz 23:2adf23ee0305 114 controller->i_c = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset);
benkatz 23:2adf23ee0305 115 controller->i_a = -controller->i_b - controller->i_c;
benkatz 23:2adf23ee0305 116 dq0(controller->theta_elec, controller->i_a, controller->i_b, controller->i_c, &controller->i_d, &controller->i_q); //dq0 transform on currents
benkatz 23:2adf23ee0305 117 float current = sqrt(pow(controller->i_d, 2) + pow(controller->i_q, 2));
benkatz 26:2b865c00d7e9 118 printf(" Current Angle : Rotor Angle : Raw Encoder \n\r\n\r");
benkatz 25:f5741040c4bb 119 for(int i = 0; i<n; i++){ // rotate forwards
benkatz 22:60276ba87ac6 120 for(int j = 0; j<n2; j++){
benkatz 22:60276ba87ac6 121 theta_ref += delta;
benkatz 25:f5741040c4bb 122 abc(theta_ref, v_d, v_q, &v_u, &v_v, &v_w); // inverse dq0 transform on voltages
benkatz 25:f5741040c4bb 123 svm(1.0, v_u, v_v, v_w, &dtc_u, &dtc_v, &dtc_w); // space vector modulation
benkatz 27:501fee691e0e 124 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f-dtc_u);
benkatz 25:f5741040c4bb 125 if(PHASE_ORDER){ // Check phase ordering
benkatz 27:501fee691e0e 126 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_v); // Set duty cycles
benkatz 27:501fee691e0e 127 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_w);
benkatz 22:60276ba87ac6 128 }
benkatz 22:60276ba87ac6 129 else{
benkatz 27:501fee691e0e 130 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_v);
benkatz 27:501fee691e0e 131 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_w);
benkatz 22:60276ba87ac6 132 }
benkatz 22:60276ba87ac6 133 wait_us(100);
benkatz 22:60276ba87ac6 134 ps->Sample();
benkatz 22:60276ba87ac6 135 }
benkatz 22:60276ba87ac6 136 ps->Sample();
benkatz 38:67e4e1453a4b 137 theta_actual = ps->GetMechPositionFixed();
benkatz 22:60276ba87ac6 138 error_f[i] = theta_ref/NPP - theta_actual;
benkatz 22:60276ba87ac6 139 raw_f[i] = ps->GetRawPosition();
benkatz 22:60276ba87ac6 140 printf("%.4f %.4f %d\n\r", theta_ref/(NPP), theta_actual, raw_f[i]);
benkatz 22:60276ba87ac6 141 //theta_ref += delta;
benkatz 22:60276ba87ac6 142 }
benkatz 26:2b865c00d7e9 143
benkatz 25:f5741040c4bb 144 for(int i = 0; i<n; i++){ // rotate backwards
benkatz 22:60276ba87ac6 145 for(int j = 0; j<n2; j++){
benkatz 22:60276ba87ac6 146 theta_ref -= delta;
benkatz 25:f5741040c4bb 147 abc(theta_ref, v_d, v_q, &v_u, &v_v, &v_w); // inverse dq0 transform on voltages
benkatz 25:f5741040c4bb 148 svm(1.0, v_u, v_v, v_w, &dtc_u, &dtc_v, &dtc_w); // space vector modulation
benkatz 27:501fee691e0e 149 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f-dtc_u);
benkatz 24:58c2d7571207 150 if(PHASE_ORDER){
benkatz 27:501fee691e0e 151 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_v);
benkatz 27:501fee691e0e 152 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_w);
benkatz 22:60276ba87ac6 153 }
benkatz 22:60276ba87ac6 154 else{
benkatz 27:501fee691e0e 155 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_v);
benkatz 27:501fee691e0e 156 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_w);
benkatz 22:60276ba87ac6 157 }
benkatz 22:60276ba87ac6 158 wait_us(100);
benkatz 22:60276ba87ac6 159 ps->Sample();
benkatz 22:60276ba87ac6 160 }
benkatz 25:f5741040c4bb 161 ps->Sample(); // sample position sensor
benkatz 38:67e4e1453a4b 162 theta_actual = ps->GetMechPositionFixed(); // get mechanical position
benkatz 22:60276ba87ac6 163 error_b[i] = theta_ref/NPP - theta_actual;
benkatz 22:60276ba87ac6 164 raw_b[i] = ps->GetRawPosition();
benkatz 22:60276ba87ac6 165 printf("%.4f %.4f %d\n\r", theta_ref/(NPP), theta_actual, raw_b[i]);
benkatz 22:60276ba87ac6 166 //theta_ref -= delta;
benkatz 22:60276ba87ac6 167 }
benkatz 22:60276ba87ac6 168
benkatz 22:60276ba87ac6 169 float offset = 0;
benkatz 22:60276ba87ac6 170 for(int i = 0; i<n; i++){
benkatz 25:f5741040c4bb 171 offset += (error_f[i] + error_b[n-1-i])/(2.0f*n); // calclate average position sensor offset
benkatz 22:60276ba87ac6 172 }
benkatz 25:f5741040c4bb 173 offset = fmod(offset*NPP, 2*PI); // convert mechanical angle to electrical angle
benkatz 23:2adf23ee0305 174
benkatz 22:60276ba87ac6 175
benkatz 25:f5741040c4bb 176 ps->SetElecOffset(offset); // Set position sensor offset
benkatz 23:2adf23ee0305 177 __float_reg[0] = offset;
benkatz 23:2adf23ee0305 178 E_OFFSET = offset;
benkatz 22:60276ba87ac6 179
benkatz 22:60276ba87ac6 180 /// Perform filtering to linearize position sensor eccentricity
benkatz 22:60276ba87ac6 181 /// FIR n-sample average, where n = number of samples in one electrical cycle
benkatz 22:60276ba87ac6 182 /// This filter has zero gain at electrical frequency and all integer multiples
benkatz 25:f5741040c4bb 183 /// So cogging effects should be completely filtered out.
benkatz 22:60276ba87ac6 184
benkatz 22:60276ba87ac6 185 float error[n] = {0};
benkatz 23:2adf23ee0305 186 const int window = 128;
benkatz 22:60276ba87ac6 187 float error_filt[n] = {0};
benkatz 23:2adf23ee0305 188 float cogging_current[window] = {0};
benkatz 22:60276ba87ac6 189 float mean = 0;
benkatz 25:f5741040c4bb 190 for (int i = 0; i<n; i++){ //Average the forward and back directions
benkatz 22:60276ba87ac6 191 error[i] = 0.5f*(error_f[i] + error_b[n-i-1]);
benkatz 22:60276ba87ac6 192 }
benkatz 22:60276ba87ac6 193 for (int i = 0; i<n; i++){
benkatz 22:60276ba87ac6 194 for(int j = 0; j<window; j++){
benkatz 25:f5741040c4bb 195 int ind = -window/2 + j + i; // Indexes from -window/2 to + window/2
benkatz 22:60276ba87ac6 196 if(ind<0){
benkatz 25:f5741040c4bb 197 ind += n;} // Moving average wraps around
benkatz 22:60276ba87ac6 198 else if(ind > n-1) {
benkatz 22:60276ba87ac6 199 ind -= n;}
benkatz 22:60276ba87ac6 200 error_filt[i] += error[ind]/(float)window;
benkatz 22:60276ba87ac6 201 }
benkatz 23:2adf23ee0305 202 if(i<window){
benkatz 23:2adf23ee0305 203 cogging_current[i] = current*sinf((error[i] - error_filt[i])*NPP);
benkatz 23:2adf23ee0305 204 }
benkatz 22:60276ba87ac6 205 //printf("%.4f %4f %.4f %.4f\n\r", error[i], error_filt[i], error_f[i], error_b[i]);
benkatz 22:60276ba87ac6 206 mean += error_filt[i]/n;
benkatz 22:60276ba87ac6 207 }
benkatz 25:f5741040c4bb 208 int raw_offset = (raw_f[0] + raw_b[n-1])/2; //Insensitive to errors in this direction, so 2 points is plenty
benkatz 28:8c7e29f719c5 209
benkatz 28:8c7e29f719c5 210
benkatz 23:2adf23ee0305 211 printf("\n\r Encoder non-linearity compensation table\n\r");
benkatz 23:2adf23ee0305 212 printf(" Sample Number : Lookup Index : Lookup Value : Cogging Current Lookup\n\r\n\r");
benkatz 25:f5741040c4bb 213 for (int i = 0; i<n_lut; i++){ // build lookup table
benkatz 22:60276ba87ac6 214 int ind = (raw_offset>>7) + i;
benkatz 22:60276ba87ac6 215 if(ind > (n_lut-1)){
benkatz 22:60276ba87ac6 216 ind -= n_lut;
benkatz 22:60276ba87ac6 217 }
benkatz 22:60276ba87ac6 218 lut[ind] = (int) ((error_filt[i*NPP] - mean)*(float)(ps->GetCPR())/(2.0f*PI));
benkatz 23:2adf23ee0305 219 printf("%d %d %d %f\n\r", i, ind, lut[ind], cogging_current[i]);
benkatz 26:2b865c00d7e9 220 wait(.001);
benkatz 22:60276ba87ac6 221 }
benkatz 23:2adf23ee0305 222
benkatz 25:f5741040c4bb 223 ps->WriteLUT(lut); // write lookup table to position sensor object
benkatz 23:2adf23ee0305 224 //memcpy(controller->cogging, cogging_current, sizeof(controller->cogging)); //compensation doesn't actually work yet....
benkatz 25:f5741040c4bb 225 memcpy(&ENCODER_LUT, lut, sizeof(lut)); // copy the lookup table to the flash array
benkatz 23:2adf23ee0305 226 printf("\n\rEncoder Electrical Offset (rad) %f\n\r", offset);
benkatz 22:60276ba87ac6 227
benkatz 23:2adf23ee0305 228 if (!prefs->ready()) prefs->open();
benkatz 25:f5741040c4bb 229 prefs->flush(); // write offset and lookup table to flash
benkatz 25:f5741040c4bb 230 prefs->close();
benkatz 23:2adf23ee0305 231
benkatz 23:2adf23ee0305 232
benkatz 22:60276ba87ac6 233 }