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Mini Cheetah Actuator Branch Superseded by: https://github.com/bgkatz/motorcontrol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Superseded by: https://github.com/bgkatz/motorcontrol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@47:e1196a851f76, 2018-12-05 (annotated)

Committer:
benkatz
Date:
Wed Dec 05 04:07:46 2018 +0000
Revision:
47:e1196a851f76
Parent:
46:2d4b1dafcfe3
Child:
48:74a40481740c
albert revision;

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 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 47:e1196a851f76 52
benkatz 25:f5741040c4bb 53 void zero_current(int *offset_1, int *offset_2){ // Measure zero-offset of the current sensors
benkatz 22:60276ba87ac6 54 int adc1_offset = 0;
benkatz 22:60276ba87ac6 55 int adc2_offset = 0;
benkatz 22:60276ba87ac6 56 int n = 1024;
benkatz 25:f5741040c4bb 57 for (int i = 0; i<n; i++){ // Average n samples of the ADC
benkatz 27:501fee691e0e 58 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f); // Write duty cycles
benkatz 27:501fee691e0e 59 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f);
benkatz 27:501fee691e0e 60 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f);
benkatz 26:2b865c00d7e9 61 ADC1->CR2 |= 0x40000000; // Begin sample and conversion
benkatz 22:60276ba87ac6 62 wait(.001);
benkatz 22:60276ba87ac6 63 adc2_offset += ADC2->DR;
benkatz 22:60276ba87ac6 64 adc1_offset += ADC1->DR;
benkatz 22:60276ba87ac6 65 }
benkatz 22:60276ba87ac6 66 *offset_1 = adc1_offset/n;
benkatz 22:60276ba87ac6 67 *offset_2 = adc2_offset/n;
benkatz 22:60276ba87ac6 68 }
benkatz 45:26801179208e 69
benkatz 45:26801179208e 70 void init_controller_params(ControllerStruct *controller){
benkatz 45:26801179208e 71 controller->ki_d = KI_D;
benkatz 45:26801179208e 72 controller->ki_q = KI_Q;
benkatz 45:26801179208e 73 controller->k_d = K_SCALE*I_BW;
benkatz 45:26801179208e 74 controller->k_q = K_SCALE*I_BW;
benkatz 45:26801179208e 75 controller->alpha = 1.0f - 1.0f/(1.0f - DT*I_BW*2.0f*PI);
benkatz 45:26801179208e 76
benkatz 45:26801179208e 77 }
benkatz 22:60276ba87ac6 78
benkatz 22:60276ba87ac6 79 void reset_foc(ControllerStruct *controller){
benkatz 28:8c7e29f719c5 80 TIM1->CCR3 = (PWM_ARR>>1)*(0.5f);
benkatz 28:8c7e29f719c5 81 TIM1->CCR1 = (PWM_ARR>>1)*(0.5f);
benkatz 28:8c7e29f719c5 82 TIM1->CCR2 = (PWM_ARR>>1)*(0.5f);
benkatz 28:8c7e29f719c5 83 controller->i_d_ref = 0;
benkatz 28:8c7e29f719c5 84 controller->i_q_ref = 0;
benkatz 28:8c7e29f719c5 85 controller->i_d = 0;
benkatz 28:8c7e29f719c5 86 controller->i_q = 0;
benkatz 37:c0f352d6e8e3 87 controller->i_q_filt = 0;
benkatz 22:60276ba87ac6 88 controller->q_int = 0;
benkatz 22:60276ba87ac6 89 controller->d_int = 0;
benkatz 28:8c7e29f719c5 90 controller->v_q = 0;
benkatz 28:8c7e29f719c5 91 controller->v_d = 0;
benkatz 47:e1196a851f76 92
benkatz 22:60276ba87ac6 93 }
benkatz 45:26801179208e 94
benkatz 45:26801179208e 95 void limit_current_ref (ControllerStruct *controller){
benkatz 45:26801179208e 96 float i_q_max_limit = (0.5774f*controller->v_bus - controller->dtheta_elec*WB)/R_PHASE;
benkatz 45:26801179208e 97 float i_q_min_limit = (-0.5774f*controller->v_bus - controller->dtheta_elec*WB)/R_PHASE;
benkatz 45:26801179208e 98 controller->i_q_ref = fmaxf(fminf(i_q_max_limit, controller->i_q_ref), i_q_min_limit);
benkatz 45:26801179208e 99 }
benkatz 22:60276ba87ac6 100
benkatz 22:60276ba87ac6 101
benkatz 47:e1196a851f76 102 void commutate(ControllerStruct *controller, GPIOStruct *gpio, float theta){
benkatz 47:e1196a851f76 103
benkatz 25:f5741040c4bb 104 /// Commutation Loop ///
benkatz 25:f5741040c4bb 105 controller->loop_count ++;
benkatz 25:f5741040c4bb 106 if(PHASE_ORDER){ // Check current sensor ordering
benkatz 25:f5741040c4bb 107 controller->i_b = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset); // Calculate phase currents from ADC readings
benkatz 22:60276ba87ac6 108 controller->i_c = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset);
benkatz 22:60276ba87ac6 109 }
benkatz 22:60276ba87ac6 110 else{
benkatz 25:f5741040c4bb 111 controller->i_b = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset);
benkatz 22:60276ba87ac6 112 controller->i_c = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset);
benkatz 22:60276ba87ac6 113 }
benkatz 26:2b865c00d7e9 114 controller->i_a = -controller->i_b - controller->i_c;
benkatz 22:60276ba87ac6 115
benkatz 26:2b865c00d7e9 116 float s = FastSin(theta);
benkatz 26:2b865c00d7e9 117 float c = FastCos(theta);
benkatz 44:8040fa2fcb0d 118 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 119 //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 120 //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 121
benkatz 37:c0f352d6e8e3 122 controller->i_q_filt = 0.95f*controller->i_q_filt + 0.05f*controller->i_q;
benkatz 47:e1196a851f76 123 controller->i_d_filt = 0.95f*controller->i_d_filt + 0.05f*controller->i_d;
benkatz 37:c0f352d6e8e3 124
benkatz 45:26801179208e 125
benkatz 45:26801179208e 126 // Filter the current references to the desired closed-loopbandwidth
benkatz 45:26801179208e 127 // Allows calculation of desired di/dt for inductance, etc
benkatz 45:26801179208e 128 controller->did_dt = controller->i_d_ref_filt;
benkatz 45:26801179208e 129 controller->diq_dt = controller->i_q_ref_filt;
benkatz 45:26801179208e 130 controller->i_d_ref_filt = (1.0f-controller->alpha)*controller->i_d_ref_filt + controller->alpha*controller->i_d_ref;
benkatz 45:26801179208e 131 controller->i_q_ref_filt = (1.0f-controller->alpha)*controller->i_q_ref_filt + controller->alpha*controller->i_q_ref;
benkatz 45:26801179208e 132 controller->did_dt = (controller->i_d_ref_filt - controller->did_dt)/DT;
benkatz 45:26801179208e 133 controller->diq_dt = (controller->i_q_ref_filt - controller->diq_dt)/DT;
benkatz 25:f5741040c4bb 134
benkatz 47:e1196a851f76 135
benkatz 47:e1196a851f76 136 /// Field Weakening ///
benkatz 47:e1196a851f76 137 /*
benkatz 47:e1196a851f76 138 controller->fw_int += .001*(0.5f*OVERMODULATION*controller->v_bus - controller->v_ref);
benkatz 47:e1196a851f76 139 controller->fw_int = fmaxf(fminf(controller->fw_int, 0.0f), -I_MAX_FW);
benkatz 47:e1196a851f76 140 controller->i_d_ref = controller->fw_int;
benkatz 47:e1196a851f76 141 float i_cmd_mag_sq = controller->i_d_ref*controller->i_d_ref + controller->i_q_ref*controller->i_q_ref;
benkatz 47:e1196a851f76 142 limit_norm(&controller->i_d_ref, &controller->i_q_ref, I_MAX);
benkatz 47:e1196a851f76 143
benkatz 47:e1196a851f76 144 */
benkatz 47:e1196a851f76 145
benkatz 25:f5741040c4bb 146 /// PI Controller ///
benkatz 22:60276ba87ac6 147 float i_d_error = controller->i_d_ref - controller->i_d;
benkatz 45:26801179208e 148 float i_q_error = controller->i_q_ref - controller->i_q;// + cogging_current;
benkatz 37:c0f352d6e8e3 149
benkatz 45:26801179208e 150 // Calculate feed-forward voltages //
benkatz 47:e1196a851f76 151 float v_d_ff = 2.0f*(1.0f*controller->i_d_ref*R_PHASE - controller->dtheta_elec*L_Q*controller->i_q); //feed-forward voltages
benkatz 47:e1196a851f76 152 float v_q_ff = 2.0f*(1.0f*controller->i_q_ref*R_PHASE + controller->dtheta_elec*(L_D*controller->i_d + 1.0f*WB));
benkatz 37:c0f352d6e8e3 153
benkatz 45:26801179208e 154 // Integrate Error //
benkatz 47:e1196a851f76 155 controller->d_int += controller->k_d*controller->ki_d*i_d_error;
benkatz 47:e1196a851f76 156 controller->q_int += controller->k_q*controller->ki_q*i_q_error;
benkatz 47:e1196a851f76 157
benkatz 47:e1196a851f76 158 controller->d_int = fmaxf(fminf(controller->d_int, OVERMODULATION*controller->v_bus), - OVERMODULATION*controller->v_bus);
benkatz 47:e1196a851f76 159 controller->q_int = fmaxf(fminf(controller->q_int, OVERMODULATION*controller->v_bus), - OVERMODULATION*controller->v_bus);
benkatz 47:e1196a851f76 160
benkatz 47:e1196a851f76 161 //limit_norm(&controller->d_int, &controller->q_int, OVERMODULATION*controller->v_bus);
benkatz 47:e1196a851f76 162 controller->v_d = controller->k_d*i_d_error + controller->d_int ;//+ v_d_ff;
benkatz 47:e1196a851f76 163 controller->v_q = controller->k_q*i_q_error + controller->q_int ;//+ v_q_ff;
benkatz 47:e1196a851f76 164
benkatz 47:e1196a851f76 165 controller->v_ref = sqrt(controller->v_d*controller->v_d + controller->v_q*controller->v_q);
benkatz 22:60276ba87ac6 166
benkatz 44:8040fa2fcb0d 167 limit_norm(&controller->v_d, &controller->v_q, OVERMODULATION*controller->v_bus); // Normalize voltage vector to lie within curcle of radius v_bus
benkatz 47:e1196a851f76 168 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 169 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 170
benkatz 25:f5741040c4bb 171 if(PHASE_ORDER){ // Check which phase order to use,
benkatz 31:61eb6ae28215 172 TIM1->CCR3 = (PWM_ARR)*(1.0f-controller->dtc_u); // Write duty cycles
benkatz 31:61eb6ae28215 173 TIM1->CCR2 = (PWM_ARR)*(1.0f-controller->dtc_v);
benkatz 31:61eb6ae28215 174 TIM1->CCR1 = (PWM_ARR)*(1.0f-controller->dtc_w);
benkatz 22:60276ba87ac6 175 }
benkatz 22:60276ba87ac6 176 else{
benkatz 32:ccac5da77844 177 TIM1->CCR3 = (PWM_ARR)*(1.0f-controller->dtc_u);
benkatz 32:ccac5da77844 178 TIM1->CCR1 = (PWM_ARR)*(1.0f-controller->dtc_v);
benkatz 32:ccac5da77844 179 TIM1->CCR2 = (PWM_ARR)*(1.0f-controller->dtc_w);
benkatz 22:60276ba87ac6 180 }
benkatz 25:f5741040c4bb 181
benkatz 25:f5741040c4bb 182 controller->theta_elec = theta; //For some reason putting this at the front breaks thins
benkatz 22:60276ba87ac6 183
benkatz 22:60276ba87ac6 184 }
benkatz 26:2b865c00d7e9 185
benkatz 26:2b865c00d7e9 186
benkatz 26:2b865c00d7e9 187 void torque_control(ControllerStruct *controller){
benkatz 28:8c7e29f719c5 188 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 189 //float torque_ref = -.1*(controller->p_des - controller->theta_mech);
benkatz 26:2b865c00d7e9 190 controller->i_q_ref = torque_ref/KT_OUT;
benkatz 37:c0f352d6e8e3 191 controller->i_d_ref = 0.0f;
benkatz 26:2b865c00d7e9 192 }
benkatz 47:e1196a851f76 193