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Mini Cheetah Actuator Branch Superseded by: https://github.com/bgkatz/motorcontrol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Superseded by: https://github.com/bgkatz/motorcontrol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@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 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 22:60276ba87ac6 36 float v_offset = (fminf3(u, v, w) + fmaxf3(u, v, w))/2.0f;
benkatz 31:61eb6ae28215 37 *dtc_u = fminf(fmaxf(((u -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX);
benkatz 31:61eb6ae28215 38 *dtc_v = fminf(fmaxf(((v -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX);
benkatz 31:61eb6ae28215 39 *dtc_w = fminf(fmaxf(((w -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX);
benkatz 22:60276ba87ac6 40
benkatz 22:60276ba87ac6 41 }
benkatz 22:60276ba87ac6 42
benkatz 25:f5741040c4bb 43 void zero_current(int *offset_1, int *offset_2){ // Measure zero-offset of the current sensors
benkatz 22:60276ba87ac6 44 int adc1_offset = 0;
benkatz 22:60276ba87ac6 45 int adc2_offset = 0;
benkatz 22:60276ba87ac6 46 int n = 1024;
benkatz 25:f5741040c4bb 47 for (int i = 0; i<n; i++){ // Average n samples of the ADC
benkatz 27:501fee691e0e 48 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f); // Write duty cycles
benkatz 27:501fee691e0e 49 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f);
benkatz 27:501fee691e0e 50 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f);
benkatz 26:2b865c00d7e9 51 ADC1->CR2 |= 0x40000000; // Begin sample and conversion
benkatz 22:60276ba87ac6 52 wait(.001);
benkatz 22:60276ba87ac6 53 adc2_offset += ADC2->DR;
benkatz 22:60276ba87ac6 54 adc1_offset += ADC1->DR;
benkatz 22:60276ba87ac6 55 }
benkatz 22:60276ba87ac6 56 *offset_1 = adc1_offset/n;
benkatz 22:60276ba87ac6 57 *offset_2 = adc2_offset/n;
benkatz 22:60276ba87ac6 58 }
benkatz 45:26801179208e 59
benkatz 45:26801179208e 60 void init_controller_params(ControllerStruct *controller){
benkatz 45:26801179208e 61 controller->ki_d = KI_D;
benkatz 45:26801179208e 62 controller->ki_q = KI_Q;
benkatz 45:26801179208e 63 controller->k_d = K_SCALE*I_BW;
benkatz 45:26801179208e 64 controller->k_q = K_SCALE*I_BW;
benkatz 45:26801179208e 65 controller->alpha = 1.0f - 1.0f/(1.0f - DT*I_BW*2.0f*PI);
benkatz 45:26801179208e 66
benkatz 45:26801179208e 67 }
benkatz 22:60276ba87ac6 68
benkatz 22:60276ba87ac6 69 void reset_foc(ControllerStruct *controller){
benkatz 28:8c7e29f719c5 70 TIM1->CCR3 = (PWM_ARR>>1)*(0.5f);
benkatz 28:8c7e29f719c5 71 TIM1->CCR1 = (PWM_ARR>>1)*(0.5f);
benkatz 28:8c7e29f719c5 72 TIM1->CCR2 = (PWM_ARR>>1)*(0.5f);
benkatz 28:8c7e29f719c5 73 controller->i_d_ref = 0;
benkatz 28:8c7e29f719c5 74 controller->i_q_ref = 0;
benkatz 28:8c7e29f719c5 75 controller->i_d = 0;
benkatz 28:8c7e29f719c5 76 controller->i_q = 0;
benkatz 37:c0f352d6e8e3 77 controller->i_q_filt = 0;
benkatz 22:60276ba87ac6 78 controller->q_int = 0;
benkatz 22:60276ba87ac6 79 controller->d_int = 0;
benkatz 28:8c7e29f719c5 80 controller->v_q = 0;
benkatz 28:8c7e29f719c5 81 controller->v_d = 0;
benkatz 22:60276ba87ac6 82 }
benkatz 45:26801179208e 83
benkatz 45:26801179208e 84 void limit_current_ref (ControllerStruct *controller){
benkatz 45:26801179208e 85 float i_q_max_limit = (0.5774f*controller->v_bus - controller->dtheta_elec*WB)/R_PHASE;
benkatz 45:26801179208e 86 float i_q_min_limit = (-0.5774f*controller->v_bus - controller->dtheta_elec*WB)/R_PHASE;
benkatz 45:26801179208e 87 controller->i_q_ref = fmaxf(fminf(i_q_max_limit, controller->i_q_ref), i_q_min_limit);
benkatz 45:26801179208e 88 }
benkatz 22:60276ba87ac6 89
benkatz 22:60276ba87ac6 90
benkatz 37:c0f352d6e8e3 91 void commutate(ControllerStruct *controller, ObserverStruct *observer, GPIOStruct *gpio, float theta){
benkatz 37:c0f352d6e8e3 92 /// Observer Prediction ///
benkatz 37:c0f352d6e8e3 93 observer->i_d_est += DT*(observer->i_d_dot);
benkatz 37:c0f352d6e8e3 94 observer->i_q_est += DT*(observer->i_q_dot);
benkatz 37:c0f352d6e8e3 95
benkatz 25:f5741040c4bb 96 /// Commutation Loop ///
benkatz 25:f5741040c4bb 97 controller->loop_count ++;
benkatz 25:f5741040c4bb 98 if(PHASE_ORDER){ // Check current sensor ordering
benkatz 25:f5741040c4bb 99 controller->i_b = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset); // Calculate phase currents from ADC readings
benkatz 22:60276ba87ac6 100 controller->i_c = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset);
benkatz 22:60276ba87ac6 101 }
benkatz 22:60276ba87ac6 102 else{
benkatz 25:f5741040c4bb 103 controller->i_b = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset);
benkatz 22:60276ba87ac6 104 controller->i_c = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset);
benkatz 22:60276ba87ac6 105 }
benkatz 26:2b865c00d7e9 106 controller->i_a = -controller->i_b - controller->i_c;
benkatz 22:60276ba87ac6 107
benkatz 26:2b865c00d7e9 108 float s = FastSin(theta);
benkatz 26:2b865c00d7e9 109 float c = FastCos(theta);
benkatz 44:8040fa2fcb0d 110 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 111 //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 112 //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 113
benkatz 37:c0f352d6e8e3 114 controller->i_q_filt = 0.95f*controller->i_q_filt + 0.05f*controller->i_q;
benkatz 37:c0f352d6e8e3 115 observer->i_d_m = controller->i_d;
benkatz 37:c0f352d6e8e3 116 observer->i_q_m = controller->i_q;
benkatz 37:c0f352d6e8e3 117
benkatz 37:c0f352d6e8e3 118 observer->e_d = observer->i_d_m - observer->i_d_est;
benkatz 37:c0f352d6e8e3 119 observer->e_q = observer->i_q_m - observer->i_q_est;
benkatz 37:c0f352d6e8e3 120 observer->e_d_int += observer->e_d;
benkatz 37:c0f352d6e8e3 121 observer->e_q_int += observer->e_q;
benkatz 37:c0f352d6e8e3 122
benkatz 37:c0f352d6e8e3 123 observer->i_d_est += K_O*observer->e_d + .001f*observer->e_d_int;
benkatz 37:c0f352d6e8e3 124 observer->i_q_est += K_O*observer->e_q + .001f*observer->e_q_int;
benkatz 37:c0f352d6e8e3 125
benkatz 37:c0f352d6e8e3 126
benkatz 45:26801179208e 127 //float scog12 = FastSin(12.0f*theta);
benkatz 45:26801179208e 128 //float scog1 = s;
benkatz 45:26801179208e 129 //float cogging_current = 0.25f*scog1 - 0.3f*scog12;
benkatz 45:26801179208e 130
benkatz 45:26801179208e 131 // Filter the current references to the desired closed-loopbandwidth
benkatz 45:26801179208e 132 // Allows calculation of desired di/dt for inductance, etc
benkatz 45:26801179208e 133 controller->did_dt = controller->i_d_ref_filt;
benkatz 45:26801179208e 134 controller->diq_dt = controller->i_q_ref_filt;
benkatz 45:26801179208e 135 controller->i_d_ref_filt = (1.0f-controller->alpha)*controller->i_d_ref_filt + controller->alpha*controller->i_d_ref;
benkatz 45:26801179208e 136 controller->i_q_ref_filt = (1.0f-controller->alpha)*controller->i_q_ref_filt + controller->alpha*controller->i_q_ref;
benkatz 45:26801179208e 137 controller->did_dt = (controller->i_d_ref_filt - controller->did_dt)/DT;
benkatz 45:26801179208e 138 controller->diq_dt = (controller->i_q_ref_filt - controller->diq_dt)/DT;
benkatz 25:f5741040c4bb 139
benkatz 25:f5741040c4bb 140 /// PI Controller ///
benkatz 22:60276ba87ac6 141 float i_d_error = controller->i_d_ref - controller->i_d;
benkatz 45:26801179208e 142 float i_q_error = controller->i_q_ref - controller->i_q;// + cogging_current;
benkatz 37:c0f352d6e8e3 143
benkatz 45:26801179208e 144 // Calculate feed-forward voltages //
benkatz 45:26801179208e 145 float v_d_ff = 2.0f*(controller->i_d_ref*R_PHASE + L_D*controller->did_dt - controller->dtheta_elec*L_Q*controller->i_q_ref); //feed-forward voltages
benkatz 45:26801179208e 146 float v_q_ff = 2.0f*(controller->i_q_ref*R_PHASE + L_Q*controller->diq_dt + controller->dtheta_elec*(L_D*controller->i_d_ref + WB));
benkatz 37:c0f352d6e8e3 147
benkatz 45:26801179208e 148 // Integrate Error //
benkatz 22:60276ba87ac6 149 controller->d_int += i_d_error;
benkatz 22:60276ba87ac6 150 controller->q_int += i_q_error;
benkatz 45:26801179208e 151
benkatz 45:26801179208e 152 limit_norm(&controller->d_int, &controller->q_int, V_BUS/(controller->k_q*controller->ki_q));
benkatz 45:26801179208e 153 controller->v_d = controller->k_d*(i_d_error + controller->ki_d*controller->d_int);// + v_d_ff;
benkatz 45:26801179208e 154 controller->v_q = controller->k_q*(i_q_error + controller->ki_q*controller->q_int);// + v_q_ff;
benkatz 22:60276ba87ac6 155
benkatz 44:8040fa2fcb0d 156 limit_norm(&controller->v_d, &controller->v_q, OVERMODULATION*controller->v_bus); // Normalize voltage vector to lie within curcle of radius v_bus
benkatz 45:26801179208e 157 abc(controller->theta_elec, controller->v_d, controller->v_q, &controller->v_u, &controller->v_v, &controller->v_w); //inverse dq0 transform on voltages
benkatz 22:60276ba87ac6 158 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 159
benkatz 37:c0f352d6e8e3 160 observer->i_d_dot = 0.5f*(controller->v_d - 2.0f*(observer->i_d_est*R_PHASE - controller->dtheta_elec*L_Q*observer->i_q_est))/L_D; //feed-forward voltage
benkatz 37:c0f352d6e8e3 161 observer->i_q_dot = 0.5f*(controller->v_q - 2.0f*(observer->i_q_est*R_PHASE + controller->dtheta_elec*(L_D*observer->i_d_est + WB)))/L_Q;
benkatz 22:60276ba87ac6 162
benkatz 45:26801179208e 163 //controller->dtc_u = 0.5f;
benkatz 45:26801179208e 164 //controller->dtc_v = 0.6f;
benkatz 45:26801179208e 165 //controller->dtc_w = 0.5f;
benkatz 25:f5741040c4bb 166 if(PHASE_ORDER){ // Check which phase order to use,
benkatz 31:61eb6ae28215 167 TIM1->CCR3 = (PWM_ARR)*(1.0f-controller->dtc_u); // Write duty cycles
benkatz 31:61eb6ae28215 168 TIM1->CCR2 = (PWM_ARR)*(1.0f-controller->dtc_v);
benkatz 31:61eb6ae28215 169 TIM1->CCR1 = (PWM_ARR)*(1.0f-controller->dtc_w);
benkatz 22:60276ba87ac6 170 }
benkatz 22:60276ba87ac6 171 else{
benkatz 32:ccac5da77844 172 TIM1->CCR3 = (PWM_ARR)*(1.0f-controller->dtc_u);
benkatz 32:ccac5da77844 173 TIM1->CCR1 = (PWM_ARR)*(1.0f-controller->dtc_v);
benkatz 32:ccac5da77844 174 TIM1->CCR2 = (PWM_ARR)*(1.0f-controller->dtc_w);
benkatz 22:60276ba87ac6 175 }
benkatz 25:f5741040c4bb 176
benkatz 25:f5741040c4bb 177 controller->theta_elec = theta; //For some reason putting this at the front breaks thins
benkatz 22:60276ba87ac6 178
benkatz 22:60276ba87ac6 179
benkatz 31:61eb6ae28215 180 if(controller->loop_count >400){
benkatz 22:60276ba87ac6 181 //controller->i_q_ref = -controller->i_q_ref;
benkatz 26:2b865c00d7e9 182 controller->loop_count = 0;
benkatz 22:60276ba87ac6 183
benkatz 28:8c7e29f719c5 184 //printf("%.2f %.2f %.2f\n\r", controller->i_a, controller->i_b, controller->i_c);
benkatz 31:61eb6ae28215 185 //printf("%f\n\r", controller->dtheta_mech*GR);
benkatz 22:60276ba87ac6 186 //pc.printf("%f %f %f\n\r", controller->i_a, controller->i_b, controller->i_c);
benkatz 45:26801179208e 187 //printf("%f %f\n\r", controller->k_d, controller->k_q);
benkatz 22:60276ba87ac6 188 //pc.printf("%d %d\n\r", controller->adc1_raw, controller->adc2_raw);
benkatz 26:2b865c00d7e9 189 }
benkatz 22:60276ba87ac6 190 }
benkatz 26:2b865c00d7e9 191
benkatz 26:2b865c00d7e9 192
benkatz 26:2b865c00d7e9 193 void torque_control(ControllerStruct *controller){
benkatz 28:8c7e29f719c5 194 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 195 //float torque_ref = -.1*(controller->p_des - controller->theta_mech);
benkatz 26:2b865c00d7e9 196 controller->i_q_ref = torque_ref/KT_OUT;
benkatz 37:c0f352d6e8e3 197 controller->i_d_ref = 0.0f;
benkatz 26:2b865c00d7e9 198 }
benkatz 26:2b865c00d7e9 199
benkatz 26:2b865c00d7e9 200
benkatz 22:60276ba87ac6 201 /*
benkatz 22:60276ba87ac6 202 void zero_encoder(ControllerStruct *controller, GPIOStruct *gpio, ){
benkatz 22:60276ba87ac6 203
benkatz 22:60276ba87ac6 204 }
benkatz 22:60276ba87ac6 205 */