Ben Katz / HKC_MiniCheetah

Mini Cheetah Actuator Branch Superseded by: https://github.com/bgkatz/motorcontrol

Dependencies:   mbed-dev-f303 FastPWM3

Superseded by: https://github.com/bgkatz/motorcontrol

FOC/foc.cpp@53:e85efce8c1eb, 2019-08-08 (annotated)

Committer:
benkatz
Date:
Thu Aug 08 17:19:39 2019 +0000
Revision:
53:e85efce8c1eb
Parent:
51:6cd89bd6fcaa
Child:
55:c4c9fec8539c
fixed CAN ID filtering bug

Who changed what in which revision?

UserRevisionLine numberNew contents of line
benkatz 37:c0f352d6e8e3 1
benkatz 22:60276ba87ac6 2 #include "foc.h"
benkatz 26:2b865c00d7e9 3 using namespace FastMath;
benkatz 22:60276ba87ac6 4
benkatz 22:60276ba87ac6 5
benkatz 22:60276ba87ac6 6 void abc( float theta, float d, float q, float *a, float *b, float *c){
benkatz 25:f5741040c4bb 7 /// Inverse DQ0 Transform ///
benkatz 22:60276ba87ac6 8 ///Phase current amplitude = lengh of dq vector///
benkatz 22:60276ba87ac6 9 ///i.e. iq = 1, id = 0, peak phase current of 1///
benkatz 37:c0f352d6e8e3 10 float cf = FastCos(theta);
benkatz 37:c0f352d6e8e3 11 float sf = FastSin(theta);
benkatz 37:c0f352d6e8e3 12
benkatz 37:c0f352d6e8e3 13 *a = cf*d - sf*q; // Faster Inverse DQ0 transform
benkatz 37:c0f352d6e8e3 14 *b = (0.86602540378f*sf-.5f*cf)*d - (-0.86602540378f*cf-.5f*sf)*q;
benkatz 37:c0f352d6e8e3 15 *c = (-0.86602540378f*sf-.5f*cf)*d - (0.86602540378f*cf-.5f*sf)*q;
benkatz 22:60276ba87ac6 16 }
benkatz 22:60276ba87ac6 17
benkatz 26:2b865c00d7e9 18
benkatz 22:60276ba87ac6 19 void dq0(float theta, float a, float b, float c, float *d, float *q){
benkatz 25:f5741040c4bb 20 /// DQ0 Transform ///
benkatz 22:60276ba87ac6 21 ///Phase current amplitude = lengh of dq vector///
benkatz 22:60276ba87ac6 22 ///i.e. iq = 1, id = 0, peak phase current of 1///
benkatz 22:60276ba87ac6 23
benkatz 37:c0f352d6e8e3 24 float cf = FastCos(theta);
benkatz 37:c0f352d6e8e3 25 float sf = FastSin(theta);
benkatz 26:2b865c00d7e9 26
benkatz 37:c0f352d6e8e3 27 *d = 0.6666667f*(cf*a + (0.86602540378f*sf-.5f*cf)*b + (-0.86602540378f*sf-.5f*cf)*c); ///Faster DQ0 Transform
benkatz 37:c0f352d6e8e3 28 *q = 0.6666667f*(-sf*a - (-0.86602540378f*cf-.5f*sf)*b - (0.86602540378f*cf-.5f*sf)*c);
benkatz 37:c0f352d6e8e3 29
benkatz 22:60276ba87ac6 30 }
benkatz 22:60276ba87ac6 31
benkatz 22:60276ba87ac6 32 void svm(float v_bus, float u, float v, float w, float *dtc_u, float *dtc_v, float *dtc_w){
benkatz 25:f5741040c4bb 33 /// Space Vector Modulation ///
benkatz 25:f5741040c4bb 34 /// u,v,w amplitude = v_bus for full modulation depth ///
benkatz 22:60276ba87ac6 35
benkatz 48:74a40481740c 36 float v_offset = (fminf3(u, v, w) + fmaxf3(u, v, w))*0.5f;
benkatz 47:e1196a851f76 37
benkatz 31:61eb6ae28215 38 *dtc_u = fminf(fmaxf(((u -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX);
benkatz 31:61eb6ae28215 39 *dtc_v = fminf(fmaxf(((v -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX);
benkatz 47:e1196a851f76 40 *dtc_w = fminf(fmaxf(((w -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX);
benkatz 47:e1196a851f76 41
benkatz 47:e1196a851f76 42 /*
benkatz 47:e1196a851f76 43 sinusoidal pwm
benkatz 47:e1196a851f76 44 *dtc_u = fminf(fmaxf((u/v_bus + .5f), DTC_MIN), DTC_MAX);
benkatz 47:e1196a851f76 45 *dtc_v = fminf(fmaxf((v/v_bus + .5f), DTC_MIN), DTC_MAX);
benkatz 47:e1196a851f76 46 *dtc_w = fminf(fmaxf((w/v_bus + .5f), DTC_MIN), DTC_MAX);
benkatz 47:e1196a851f76 47 */
benkatz 47:e1196a851f76 48
benkatz 22:60276ba87ac6 49
benkatz 22:60276ba87ac6 50 }
benkatz 22:60276ba87ac6 51
benkatz 48:74a40481740c 52 void linearize_dtc(float *dtc){
benkatz 48:74a40481740c 53 /// linearizes the output of the inverter, which is not linear for small duty cycles ///
benkatz 48:74a40481740c 54 float sgn = 1.0f-(2.0f*(dtc<0));
benkatz 48:74a40481740c 55 if(abs(*dtc) >= .01f){
benkatz 48:74a40481740c 56 *dtc = *dtc*.986f+.014f*sgn;
benkatz 48:74a40481740c 57 }
benkatz 48:74a40481740c 58 else{
benkatz 48:74a40481740c 59 *dtc = 2.5f*(*dtc);
benkatz 48:74a40481740c 60 }
benkatz 48:74a40481740c 61
benkatz 48:74a40481740c 62 }
benkatz 48:74a40481740c 63
benkatz 48:74a40481740c 64
benkatz 25:f5741040c4bb 65 void zero_current(int *offset_1, int *offset_2){ // Measure zero-offset of the current sensors
benkatz 22:60276ba87ac6 66 int adc1_offset = 0;
benkatz 22:60276ba87ac6 67 int adc2_offset = 0;
benkatz 22:60276ba87ac6 68 int n = 1024;
benkatz 25:f5741040c4bb 69 for (int i = 0; i<n; i++){ // Average n samples of the ADC
benkatz 27:501fee691e0e 70 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f); // Write duty cycles
benkatz 27:501fee691e0e 71 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f);
benkatz 27:501fee691e0e 72 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f);
benkatz 26:2b865c00d7e9 73 ADC1->CR2 |= 0x40000000; // Begin sample and conversion
benkatz 22:60276ba87ac6 74 wait(.001);
benkatz 22:60276ba87ac6 75 adc2_offset += ADC2->DR;
benkatz 22:60276ba87ac6 76 adc1_offset += ADC1->DR;
benkatz 22:60276ba87ac6 77 }
benkatz 22:60276ba87ac6 78 *offset_1 = adc1_offset/n;
benkatz 22:60276ba87ac6 79 *offset_2 = adc2_offset/n;
benkatz 22:60276ba87ac6 80 }
benkatz 45:26801179208e 81
benkatz 45:26801179208e 82 void init_controller_params(ControllerStruct *controller){
benkatz 45:26801179208e 83 controller->ki_d = KI_D;
benkatz 45:26801179208e 84 controller->ki_q = KI_Q;
benkatz 45:26801179208e 85 controller->k_d = K_SCALE*I_BW;
benkatz 45:26801179208e 86 controller->k_q = K_SCALE*I_BW;
benkatz 45:26801179208e 87 controller->alpha = 1.0f - 1.0f/(1.0f - DT*I_BW*2.0f*PI);
benkatz 45:26801179208e 88
benkatz 45:26801179208e 89 }
benkatz 22:60276ba87ac6 90
benkatz 22:60276ba87ac6 91 void reset_foc(ControllerStruct *controller){
benkatz 28:8c7e29f719c5 92 TIM1->CCR3 = (PWM_ARR>>1)*(0.5f);
benkatz 28:8c7e29f719c5 93 TIM1->CCR1 = (PWM_ARR>>1)*(0.5f);
benkatz 28:8c7e29f719c5 94 TIM1->CCR2 = (PWM_ARR>>1)*(0.5f);
benkatz 28:8c7e29f719c5 95 controller->i_d_ref = 0;
benkatz 28:8c7e29f719c5 96 controller->i_q_ref = 0;
benkatz 28:8c7e29f719c5 97 controller->i_d = 0;
benkatz 28:8c7e29f719c5 98 controller->i_q = 0;
benkatz 37:c0f352d6e8e3 99 controller->i_q_filt = 0;
benkatz 22:60276ba87ac6 100 controller->q_int = 0;
benkatz 22:60276ba87ac6 101 controller->d_int = 0;
benkatz 28:8c7e29f719c5 102 controller->v_q = 0;
benkatz 28:8c7e29f719c5 103 controller->v_d = 0;
benkatz 47:e1196a851f76 104
benkatz 22:60276ba87ac6 105 }
benkatz 45:26801179208e 106
benkatz 48:74a40481740c 107 void reset_observer(ObserverStruct *observer){
benkatz 48:74a40481740c 108 observer->temperature = 25.0f;
benkatz 48:74a40481740c 109 observer->resistance = .1f;
benkatz 48:74a40481740c 110 }
benkatz 48:74a40481740c 111
benkatz 45:26801179208e 112 void limit_current_ref (ControllerStruct *controller){
benkatz 45:26801179208e 113 float i_q_max_limit = (0.5774f*controller->v_bus - controller->dtheta_elec*WB)/R_PHASE;
benkatz 45:26801179208e 114 float i_q_min_limit = (-0.5774f*controller->v_bus - controller->dtheta_elec*WB)/R_PHASE;
benkatz 45:26801179208e 115 controller->i_q_ref = fmaxf(fminf(i_q_max_limit, controller->i_q_ref), i_q_min_limit);
benkatz 45:26801179208e 116 }
benkatz 22:60276ba87ac6 117
benkatz 22:60276ba87ac6 118
benkatz 48:74a40481740c 119 void commutate(ControllerStruct *controller, ObserverStruct *observer, GPIOStruct *gpio, float theta){
benkatz 48:74a40481740c 120
benkatz 48:74a40481740c 121 /// Update observer estimates ///
benkatz 48:74a40481740c 122 // Resistance observer //
benkatz 48:74a40481740c 123 // Temperature Observer //
benkatz 48:74a40481740c 124 float t_rise = (float)observer->temperature - 25.0f;
benkatz 49:83d83040ea51 125 float q_th_in = (1.0f + .00393f*t_rise)*(controller->i_d*controller->i_d*R_PHASE*SQRT3 + controller->i_q*controller->i_q*R_PHASE*SQRT3);
benkatz 48:74a40481740c 126 float q_th_out = t_rise*R_TH;
benkatz 48:74a40481740c 127 observer->temperature += INV_M_TH*DT*(q_th_in-q_th_out);
benkatz 48:74a40481740c 128
benkatz 49:83d83040ea51 129 observer->resistance = (controller->v_q - SQRT3*controller->dtheta_elec*(WB))/controller->i_q;
benkatz 49:83d83040ea51 130 //observer->resistance = controller->v_q/controller->i_q;
benkatz 48:74a40481740c 131 if(isnan(observer->resistance)){observer->resistance = R_PHASE;}
benkatz 48:74a40481740c 132 observer->temperature2 = (double)(25.0f + ((observer->resistance*6.0606f)-1.0f)*275.5f);
benkatz 48:74a40481740c 133 double e = observer->temperature - observer->temperature2;
benkatz 48:74a40481740c 134 observer->temperature -= .001*e;
benkatz 48:74a40481740c 135 //printf("%.3f\n\r", e);
benkatz 48:74a40481740c 136
benkatz 47:e1196a851f76 137
benkatz 25:f5741040c4bb 138 /// Commutation Loop ///
benkatz 25:f5741040c4bb 139 controller->loop_count ++;
benkatz 25:f5741040c4bb 140 if(PHASE_ORDER){ // Check current sensor ordering
benkatz 25:f5741040c4bb 141 controller->i_b = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset); // Calculate phase currents from ADC readings
benkatz 22:60276ba87ac6 142 controller->i_c = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset);
benkatz 22:60276ba87ac6 143 }
benkatz 22:60276ba87ac6 144 else{
benkatz 25:f5741040c4bb 145 controller->i_b = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset);
benkatz 22:60276ba87ac6 146 controller->i_c = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset);
benkatz 22:60276ba87ac6 147 }
benkatz 26:2b865c00d7e9 148 controller->i_a = -controller->i_b - controller->i_c;
benkatz 22:60276ba87ac6 149
benkatz 26:2b865c00d7e9 150 float s = FastSin(theta);
benkatz 26:2b865c00d7e9 151 float c = FastCos(theta);
benkatz 44:8040fa2fcb0d 152 dq0(controller->theta_elec, controller->i_a, controller->i_b, controller->i_c, &controller->i_d, &controller->i_q); //dq0 transform on currents
benkatz 44:8040fa2fcb0d 153 //controller->i_d = 0.6666667f*(c*controller->i_a + (0.86602540378f*s-.5f*c)*controller->i_b + (-0.86602540378f*s-.5f*c)*controller->i_c); ///Faster DQ0 Transform
benkatz 44:8040fa2fcb0d 154 //controller->i_q = 0.6666667f*(-s*controller->i_a - (-0.86602540378f*c-.5f*s)*controller->i_b - (0.86602540378f*c-.5f*s)*controller->i_c);
benkatz 37:c0f352d6e8e3 155
benkatz 37:c0f352d6e8e3 156 controller->i_q_filt = 0.95f*controller->i_q_filt + 0.05f*controller->i_q;
benkatz 47:e1196a851f76 157 controller->i_d_filt = 0.95f*controller->i_d_filt + 0.05f*controller->i_d;
benkatz 37:c0f352d6e8e3 158
benkatz 45:26801179208e 159
benkatz 49:83d83040ea51 160 // Filter the current references to the desired closed-loop bandwidth
benkatz 45:26801179208e 161 controller->i_d_ref_filt = (1.0f-controller->alpha)*controller->i_d_ref_filt + controller->alpha*controller->i_d_ref;
benkatz 45:26801179208e 162 controller->i_q_ref_filt = (1.0f-controller->alpha)*controller->i_q_ref_filt + controller->alpha*controller->i_q_ref;
benkatz 48:74a40481740c 163
benkatz 48:74a40481740c 164
benkatz 48:74a40481740c 165 /// Field Weakening ///
benkatz 48:74a40481740c 166
benkatz 48:74a40481740c 167 controller->fw_int += .001f*(0.5f*OVERMODULATION*controller->v_bus - controller->v_ref);
benkatz 51:6cd89bd6fcaa 168 controller->fw_int = fmaxf(fminf(controller->fw_int, 0.0f), -I_FW_MAX);
benkatz 48:74a40481740c 169 controller->i_d_ref = controller->fw_int;
benkatz 48:74a40481740c 170 //float i_cmd_mag_sq = controller->i_d_ref*controller->i_d_ref + controller->i_q_ref*controller->i_q_ref;
benkatz 48:74a40481740c 171 limit_norm(&controller->i_d_ref, &controller->i_q_ref, I_MAX);
benkatz 25:f5741040c4bb 172
benkatz 47:e1196a851f76 173
benkatz 47:e1196a851f76 174
benkatz 25:f5741040c4bb 175 /// PI Controller ///
benkatz 22:60276ba87ac6 176 float i_d_error = controller->i_d_ref - controller->i_d;
benkatz 45:26801179208e 177 float i_q_error = controller->i_q_ref - controller->i_q;// + cogging_current;
benkatz 37:c0f352d6e8e3 178
benkatz 45:26801179208e 179 // Calculate feed-forward voltages //
benkatz 48:74a40481740c 180 float v_d_ff = SQRT3*(1.0f*controller->i_d_ref*R_PHASE - controller->dtheta_elec*L_Q*controller->i_q); //feed-forward voltages
benkatz 48:74a40481740c 181 float v_q_ff = SQRT3*(1.0f*controller->i_q_ref*R_PHASE + controller->dtheta_elec*(L_D*controller->i_d + 1.0f*WB));
benkatz 37:c0f352d6e8e3 182
benkatz 45:26801179208e 183 // Integrate Error //
benkatz 47:e1196a851f76 184 controller->d_int += controller->k_d*controller->ki_d*i_d_error;
benkatz 47:e1196a851f76 185 controller->q_int += controller->k_q*controller->ki_q*i_q_error;
benkatz 47:e1196a851f76 186
benkatz 47:e1196a851f76 187 controller->d_int = fmaxf(fminf(controller->d_int, OVERMODULATION*controller->v_bus), - OVERMODULATION*controller->v_bus);
benkatz 47:e1196a851f76 188 controller->q_int = fmaxf(fminf(controller->q_int, OVERMODULATION*controller->v_bus), - OVERMODULATION*controller->v_bus);
benkatz 47:e1196a851f76 189
benkatz 47:e1196a851f76 190 //limit_norm(&controller->d_int, &controller->q_int, OVERMODULATION*controller->v_bus);
benkatz 47:e1196a851f76 191 controller->v_d = controller->k_d*i_d_error + controller->d_int ;//+ v_d_ff;
benkatz 47:e1196a851f76 192 controller->v_q = controller->k_q*i_q_error + controller->q_int ;//+ v_q_ff;
benkatz 47:e1196a851f76 193
benkatz 47:e1196a851f76 194 controller->v_ref = sqrt(controller->v_d*controller->v_d + controller->v_q*controller->v_q);
benkatz 22:60276ba87ac6 195
benkatz 44:8040fa2fcb0d 196 limit_norm(&controller->v_d, &controller->v_q, OVERMODULATION*controller->v_bus); // Normalize voltage vector to lie within curcle of radius v_bus
benkatz 53:e85efce8c1eb 197 //float dtc_d = controller->v_d/controller->v_bus;
benkatz 53:e85efce8c1eb 198 //float dtc_q = controller->v_q/controller->v_bus;
benkatz 53:e85efce8c1eb 199 //linearize_dtc(&dtc_d);
benkatz 53:e85efce8c1eb 200 //linearize_dtc(&dtc_q);
benkatz 53:e85efce8c1eb 201 //controller->v_d = dtc_d*controller->v_bus;
benkatz 53:e85efce8c1eb 202 //controller->v_q = dtc_q*controller->v_bus;
benkatz 47:e1196a851f76 203 abc(controller->theta_elec + 0.0f*DT*controller->dtheta_elec, controller->v_d, controller->v_q, &controller->v_u, &controller->v_v, &controller->v_w); //inverse dq0 transform on voltages
benkatz 22:60276ba87ac6 204 svm(controller->v_bus, controller->v_u, controller->v_v, controller->v_w, &controller->dtc_u, &controller->dtc_v, &controller->dtc_w); //space vector modulation
benkatz 22:60276ba87ac6 205
benkatz 25:f5741040c4bb 206 if(PHASE_ORDER){ // Check which phase order to use,
benkatz 31:61eb6ae28215 207 TIM1->CCR3 = (PWM_ARR)*(1.0f-controller->dtc_u); // Write duty cycles
benkatz 31:61eb6ae28215 208 TIM1->CCR2 = (PWM_ARR)*(1.0f-controller->dtc_v);
benkatz 31:61eb6ae28215 209 TIM1->CCR1 = (PWM_ARR)*(1.0f-controller->dtc_w);
benkatz 22:60276ba87ac6 210 }
benkatz 22:60276ba87ac6 211 else{
benkatz 32:ccac5da77844 212 TIM1->CCR3 = (PWM_ARR)*(1.0f-controller->dtc_u);
benkatz 32:ccac5da77844 213 TIM1->CCR1 = (PWM_ARR)*(1.0f-controller->dtc_v);
benkatz 32:ccac5da77844 214 TIM1->CCR2 = (PWM_ARR)*(1.0f-controller->dtc_w);
benkatz 22:60276ba87ac6 215 }
benkatz 25:f5741040c4bb 216
benkatz 48:74a40481740c 217 controller->theta_elec = theta;
benkatz 22:60276ba87ac6 218
benkatz 22:60276ba87ac6 219 }
benkatz 26:2b865c00d7e9 220
benkatz 26:2b865c00d7e9 221
benkatz 26:2b865c00d7e9 222 void torque_control(ControllerStruct *controller){
benkatz 28:8c7e29f719c5 223 float torque_ref = controller->kp*(controller->p_des - controller->theta_mech) + controller->t_ff + controller->kd*(controller->v_des - controller->dtheta_mech);
benkatz 26:2b865c00d7e9 224 //float torque_ref = -.1*(controller->p_des - controller->theta_mech);
benkatz 26:2b865c00d7e9 225 controller->i_q_ref = torque_ref/KT_OUT;
benkatz 37:c0f352d6e8e3 226 controller->i_d_ref = 0.0f;
benkatz 26:2b865c00d7e9 227 }
benkatz 47:e1196a851f76 228