WANG YUCHAO
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Motor_DRV8323RH_for_20190
mit
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calibration.cpp
00001 /// Calibration procedures for determining position sensor offset, 00002 /// phase ordering, and position sensor linearization 00003 /// 00004 00005 #include "calibration.h" 00006 #include "foc.h" 00007 #include "PreferenceWriter.h" 00008 #include "user_config.h" 00009 #include "motor_config.h" 00010 #include "current_controller_config.h" 00011 00012 void order_phases(PositionSensor *ps, GPIOStruct *gpio, ControllerStruct *controller, PreferenceWriter *prefs){ 00013 00014 ///Checks phase order, to ensure that positive Q current produces 00015 ///torque in the positive direction wrt the position sensor. 00016 printf("\n\r Checking phase ordering\n\r"); 00017 float theta_ref = 0; 00018 float theta_actual = 0; 00019 float v_d = .3f; //Put all volts on the D-Axis 00020 float v_q = 0.0f; 00021 float v_u, v_v, v_w = 0; 00022 float dtc_u, dtc_v, dtc_w = .5f; 00023 int sample_counter = 0; 00024 00025 ///Set voltage angle to zero, wait for rotor position to settle 00026 abc(theta_ref, v_d, v_q, &v_u, &v_v, &v_w); //inverse dq0 transform on voltages 00027 svm(1.0, v_u, v_v, v_w, &dtc_u, &dtc_v, &dtc_w); //space vector modulation 00028 for(int i = 0; i<20000; i++){ 00029 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f-dtc_u); // Set duty cycles 00030 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_v); 00031 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_w); 00032 wait_us(100); 00033 } 00034 //ps->ZeroPosition(); 00035 ps->Sample(DT); 00036 wait_us(1000); 00037 //float theta_start = ps->GetMechPositionFixed(); //get initial rotor position 00038 float theta_start; 00039 controller->i_b = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset); //Calculate phase currents from ADC readings 00040 controller->i_c = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset); 00041 controller->i_a = -controller->i_b - controller->i_c; 00042 dq0(controller->theta_elec, controller->i_a, controller->i_b, controller->i_c, &controller->i_d, &controller->i_q); //dq0 transform on currents 00043 float current = sqrt(pow(controller->i_d, 2) + pow(controller->i_q, 2)); 00044 printf("\n\rCurrent\n\r"); 00045 printf("%f %f %f\n\r\n\r", controller->i_d, controller->i_q, current); 00046 /// Rotate voltage angle 00047 while(theta_ref < 4*PI){ //rotate for 2 electrical cycles 00048 abc(theta_ref, v_d, v_q, &v_u, &v_v, &v_w); //inverse dq0 transform on voltages 00049 svm(1.0, v_u, v_v, v_w, &dtc_u, &dtc_v, &dtc_w); //space vector modulation 00050 wait_us(100); 00051 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f-dtc_u); //Set duty cycles 00052 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_v); 00053 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_w); 00054 ps->Sample(DT); //sample position sensor 00055 theta_actual = ps->GetMechPositionFixed(); 00056 if(theta_ref==0){theta_start = theta_actual;} 00057 if(sample_counter > 200){ 00058 sample_counter = 0 ; 00059 printf("%.4f %.4f\n\r", theta_ref/(NPP), theta_actual); 00060 } 00061 sample_counter++; 00062 theta_ref += 0.001f; 00063 } 00064 float theta_end = ps->GetMechPositionFixed(); 00065 int direction = (theta_end - theta_start)>0; 00066 printf("Theta Start: %f Theta End: %f\n\r", theta_start, theta_end); 00067 printf("Direction: %d\n\r", direction); 00068 if(direction){printf("Phasing correct\n\r");} 00069 else if(!direction){printf("Phasing incorrect. Swapping phases V and W\n\r");} 00070 PHASE_ORDER = direction; 00071 } 00072 00073 00074 void calibrate(PositionSensor *ps, GPIOStruct *gpio, ControllerStruct *controller, PreferenceWriter *prefs){ 00075 /// Measures the electrical angle offset of the position sensor 00076 /// and (in the future) corrects nonlinearity due to position sensor eccentricity 00077 printf("Starting calibration procedure\n\r"); 00078 00079 const int n = 128*NPP; // number of positions to be sampled per mechanical rotation. Multiple of NPP for filtering reasons (see later) 00080 const int n2 = 50; // increments between saved samples (for smoothing motion) 00081 float delta = 2*PI*NPP/(n*n2); // change in angle between samples 00082 float error_f[n] = {0}; // error vector rotating forwards 00083 float error_b[n] = {0}; // error vector rotating backwards 00084 const int n_lut = 128; 00085 int lut[n_lut]= {0}; // clear any old lookup table before starting. 00086 ps->WriteLUT(lut); 00087 int raw_f[n] = {0}; 00088 int raw_b[n] = {0}; 00089 float theta_ref = 0; 00090 float theta_actual = 0; 00091 float v_d = .3f; // Put volts on the D-Axis 00092 float v_q = 0.0f; 00093 float v_u, v_v, v_w = 0; 00094 float dtc_u, dtc_v, dtc_w = .5f; 00095 00096 00097 ///Set voltage angle to zero, wait for rotor position to settle 00098 abc(theta_ref, v_d, v_q, &v_u, &v_v, &v_w); // inverse dq0 transform on voltages 00099 svm(1.0, v_u, v_v, v_w, &dtc_u, &dtc_v, &dtc_w); // space vector modulation 00100 for(int i = 0; i<40000; i++){ 00101 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f-dtc_u); // Set duty cycles 00102 if(PHASE_ORDER){ 00103 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_v); 00104 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_w); 00105 } 00106 else{ 00107 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_v); 00108 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_w); 00109 } 00110 wait_us(100); 00111 } 00112 ps->Sample(DT); 00113 controller->i_b = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset); //Calculate phase currents from ADC readings 00114 controller->i_c = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset); 00115 controller->i_a = -controller->i_b - controller->i_c; 00116 dq0(controller->theta_elec, controller->i_a, controller->i_b, controller->i_c, &controller->i_d, &controller->i_q); //dq0 transform on currents 00117 float current = sqrt(pow(controller->i_d, 2) + pow(controller->i_q, 2)); 00118 printf(" Current Angle : Rotor Angle : Raw Encoder \n\r\n\r"); 00119 for(int i = 0; i<n; i++){ // rotate forwards 00120 for(int j = 0; j<n2; j++){ 00121 theta_ref += delta; 00122 abc(theta_ref, v_d, v_q, &v_u, &v_v, &v_w); // inverse dq0 transform on voltages 00123 svm(1.0, v_u, v_v, v_w, &dtc_u, &dtc_v, &dtc_w); // space vector modulation 00124 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f-dtc_u); 00125 if(PHASE_ORDER){ // Check phase ordering 00126 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_v); // Set duty cycles 00127 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_w); 00128 } 00129 else{ 00130 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_v); 00131 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_w); 00132 } 00133 wait_us(100); 00134 ps->Sample(DT); 00135 } 00136 ps->Sample(DT); 00137 theta_actual = ps->GetMechPositionFixed(); 00138 error_f[i] = theta_ref/NPP - theta_actual; 00139 raw_f[i] = ps->GetRawPosition(); 00140 printf("%.4f %.4f %d\n\r", theta_ref/(NPP), theta_actual, raw_f[i]); 00141 //theta_ref += delta; 00142 } 00143 00144 for(int i = 0; i<n; i++){ // rotate backwards 00145 for(int j = 0; j<n2; j++){ 00146 theta_ref -= delta; 00147 abc(theta_ref, v_d, v_q, &v_u, &v_v, &v_w); // inverse dq0 transform on voltages 00148 svm(1.0, v_u, v_v, v_w, &dtc_u, &dtc_v, &dtc_w); // space vector modulation 00149 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f-dtc_u); 00150 if(PHASE_ORDER){ 00151 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_v); 00152 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_w); 00153 } 00154 else{ 00155 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f-dtc_v); 00156 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f-dtc_w); 00157 } 00158 wait_us(100); 00159 ps->Sample(DT); 00160 } 00161 ps->Sample(DT); // sample position sensor 00162 theta_actual = ps->GetMechPositionFixed(); // get mechanical position 00163 error_b[i] = theta_ref/NPP - theta_actual; 00164 raw_b[i] = ps->GetRawPosition(); 00165 printf("%.4f %.4f %d\n\r", theta_ref/(NPP), theta_actual, raw_b[i]); 00166 //theta_ref -= delta; 00167 } 00168 00169 float offset = 0; 00170 for(int i = 0; i<n; i++){ 00171 offset += (error_f[i] + error_b[n-1-i])/(2.0f*n); // calclate average position sensor offset 00172 } 00173 offset = fmod(offset*NPP, 2*PI); // convert mechanical angle to electrical angle 00174 00175 00176 ps->SetElecOffset(offset); // Set position sensor offset 00177 __float_reg[0] = offset; 00178 E_OFFSET = offset; 00179 00180 /// Perform filtering to linearize position sensor eccentricity 00181 /// FIR n-sample average, where n = number of samples in one electrical cycle 00182 /// This filter has zero gain at electrical frequency and all integer multiples 00183 /// So cogging effects should be completely filtered out. 00184 00185 float error[n] = {0}; 00186 const int window = 128; 00187 float error_filt[n] = {0}; 00188 float cogging_current[window] = {0}; 00189 float mean = 0; 00190 for (int i = 0; i<n; i++){ //Average the forward and back directions 00191 error[i] = 0.5f*(error_f[i] + error_b[n-i-1]); 00192 } 00193 for (int i = 0; i<n; i++){ 00194 for(int j = 0; j<window; j++){ 00195 int ind = -window/2 + j + i; // Indexes from -window/2 to + window/2 00196 if(ind<0){ 00197 ind += n;} // Moving average wraps around 00198 else if(ind > n-1) { 00199 ind -= n;} 00200 error_filt[i] += error[ind]/(float)window; 00201 } 00202 if(i<window){ 00203 cogging_current[i] = current*sinf((error[i] - error_filt[i])*NPP); 00204 } 00205 //printf("%.4f %4f %.4f %.4f\n\r", error[i], error_filt[i], error_f[i], error_b[i]); 00206 mean += error_filt[i]/n; 00207 } 00208 int raw_offset = (raw_f[0] + raw_b[n-1])/2; //Insensitive to errors in this direction, so 2 points is plenty 00209 00210 00211 printf("\n\r Encoder non-linearity compensation table\n\r"); 00212 printf(" Sample Number : Lookup Index : Lookup Value : Cogging Current Lookup\n\r\n\r"); 00213 for (int i = 0; i<n_lut; i++){ // build lookup table 00214 int ind = (raw_offset>>7) + i; 00215 if(ind > (n_lut-1)){ 00216 ind -= n_lut; 00217 } 00218 lut[ind] = (int) ((error_filt[i*NPP] - mean)*(float)(ps->GetCPR())/(2.0f*PI)); 00219 printf("%d %d %d %f\n\r", i, ind, lut[ind], cogging_current[i]); 00220 wait(.001); 00221 } 00222 00223 ps->WriteLUT(lut); // write lookup table to position sensor object 00224 //memcpy(controller->cogging, cogging_current, sizeof(controller->cogging)); //compensation doesn't actually work yet.... 00225 memcpy(&ENCODER_LUT, lut, sizeof(lut)); // copy the lookup table to the flash array 00226 printf("\n\rEncoder Electrical Offset (rad) %f\n\r", offset); 00227 00228 if (!prefs->ready()) prefs->open(); 00229 prefs->flush(); // write offset and lookup table to flash 00230 prefs->close(); 00231 00232 00233 }
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