kinoko john
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foc.cpp
00001 00002 #include "foc.h" 00003 using namespace FastMath; 00004 00005 00006 void abc( float theta, float d, float q, float *a, float *b, float *c){ 00007 /// Inverse DQ0 Transform /// 00008 ///Phase current amplitude = lengh of dq vector/// 00009 ///i.e. iq = 1, id = 0, peak phase current of 1/// 00010 float cf = FastCos(theta); 00011 float sf = FastSin(theta); 00012 00013 *a = cf*d - sf*q; // Faster Inverse DQ0 transform 00014 *b = (0.86602540378f*sf-.5f*cf)*d - (-0.86602540378f*cf-.5f*sf)*q; 00015 *c = (-0.86602540378f*sf-.5f*cf)*d - (0.86602540378f*cf-.5f*sf)*q; 00016 } 00017 00018 00019 void dq0(float theta, float a, float b, float c, float *d, float *q){ 00020 /// DQ0 Transform /// 00021 ///Phase current amplitude = lengh of dq vector/// 00022 ///i.e. iq = 1, id = 0, peak phase current of 1/// 00023 00024 float cf = FastCos(theta); 00025 float sf = FastSin(theta); 00026 00027 *d = 0.6666667f*(cf*a + (0.86602540378f*sf-.5f*cf)*b + (-0.86602540378f*sf-.5f*cf)*c); ///Faster DQ0 Transform 00028 *q = 0.6666667f*(-sf*a - (-0.86602540378f*cf-.5f*sf)*b - (0.86602540378f*cf-.5f*sf)*c); 00029 00030 } 00031 00032 void svm(float v_bus, float u, float v, float w, float *dtc_u, float *dtc_v, float *dtc_w){ 00033 /// Space Vector Modulation /// 00034 /// u,v,w amplitude = v_bus for full modulation depth /// 00035 00036 float v_offset = (fminf3(u, v, w) + fmaxf3(u, v, w))*0.5f; 00037 00038 *dtc_u = fminf(fmaxf(((u -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX); 00039 *dtc_v = fminf(fmaxf(((v -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX); 00040 *dtc_w = fminf(fmaxf(((w -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX); 00041 00042 /* 00043 sinusoidal pwm 00044 *dtc_u = fminf(fmaxf((u/v_bus + .5f), DTC_MIN), DTC_MAX); 00045 *dtc_v = fminf(fmaxf((v/v_bus + .5f), DTC_MIN), DTC_MAX); 00046 *dtc_w = fminf(fmaxf((w/v_bus + .5f), DTC_MIN), DTC_MAX); 00047 */ 00048 00049 00050 } 00051 00052 void linearize_dtc(float *dtc){ 00053 /// linearizes the output of the inverter, which is not linear for small duty cycles /// 00054 float sgn = 1.0f-(2.0f*(dtc<0)); 00055 if(abs(*dtc) >= .01f){ 00056 *dtc = *dtc*.986f+.014f*sgn; 00057 } 00058 else{ 00059 *dtc = 2.5f*(*dtc); 00060 } 00061 00062 } 00063 00064 00065 void zero_current(int *offset_1, int *offset_2){ // Measure zero-offset of the current sensors 00066 int adc1_offset = 0; 00067 int adc2_offset = 0; 00068 int n = 1024; 00069 for (int i = 0; i<n; i++){ // Average n samples of the ADC 00070 TIM1->CCR3 = (PWM_ARR>>1)*(1.0f); // Write duty cycles 00071 TIM1->CCR2 = (PWM_ARR>>1)*(1.0f); 00072 TIM1->CCR1 = (PWM_ARR>>1)*(1.0f); 00073 ADC1->CR2 |= 0x40000000; // Begin sample and conversion 00074 wait(.001); 00075 adc2_offset += ADC2->DR; 00076 adc1_offset += ADC1->DR; 00077 } 00078 *offset_1 = adc1_offset/n; 00079 *offset_2 = adc2_offset/n; 00080 } 00081 00082 void init_controller_params(ControllerStruct *controller){ 00083 controller->ki_d = KI_D; 00084 controller->ki_q = KI_Q; 00085 controller->k_d = K_SCALE*I_BW; 00086 controller->k_q = K_SCALE*I_BW; 00087 controller->alpha = 1.0f - 1.0f/(1.0f - DT*I_BW*2.0f*PI); 00088 00089 } 00090 00091 void reset_foc(ControllerStruct *controller){ 00092 TIM1->CCR3 = (PWM_ARR>>1)*(0.5f); 00093 TIM1->CCR1 = (PWM_ARR>>1)*(0.5f); 00094 TIM1->CCR2 = (PWM_ARR>>1)*(0.5f); 00095 controller->i_d_ref = 0; 00096 controller->i_q_ref = 0; 00097 controller->i_d = 0; 00098 controller->i_q = 0; 00099 controller->i_q_filt = 0; 00100 controller->q_int = 0; 00101 controller->d_int = 0; 00102 controller->v_q = 0; 00103 controller->v_d = 0; 00104 00105 } 00106 00107 void reset_observer(ObserverStruct *observer){ 00108 observer->temperature = 25.0f; 00109 observer->resistance = .1f; 00110 } 00111 00112 void limit_current_ref (ControllerStruct *controller){ 00113 float i_q_max_limit = (0.5774f*controller->v_bus - controller->dtheta_elec*WB)/R_PHASE; 00114 float i_q_min_limit = (-0.5774f*controller->v_bus - controller->dtheta_elec*WB)/R_PHASE; 00115 controller->i_q_ref = fmaxf(fminf(i_q_max_limit, controller->i_q_ref), i_q_min_limit); 00116 } 00117 00118 00119 void commutate(ControllerStruct *controller, ObserverStruct *observer, GPIOStruct *gpio, float theta){ 00120 00121 /// Update observer estimates /// 00122 // Resistance observer // 00123 // Temperature Observer // 00124 float t_rise = (float)observer->temperature - 25.0f; 00125 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); 00126 float q_th_out = t_rise*R_TH; 00127 observer->temperature += INV_M_TH*DT*(q_th_in-q_th_out); 00128 00129 observer->resistance = (controller->v_q - SQRT3*controller->dtheta_elec*(WB))/controller->i_q; 00130 //observer->resistance = controller->v_q/controller->i_q; 00131 if(isnan(observer->resistance)){observer->resistance = R_PHASE;} 00132 observer->temperature2 = (double)(25.0f + ((observer->resistance*6.0606f)-1.0f)*275.5f); 00133 double e = observer->temperature - observer->temperature2; 00134 observer->temperature -= .001*e; 00135 //printf("%.3f\n\r", e); 00136 00137 00138 /// Commutation Loop /// 00139 controller->loop_count ++; 00140 if(PHASE_ORDER){ // Check current sensor ordering 00141 controller->i_b = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset); // Calculate phase currents from ADC readings 00142 controller->i_c = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset); 00143 } 00144 else{ 00145 controller->i_b = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset); 00146 controller->i_c = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset); 00147 } 00148 controller->i_a = -controller->i_b - controller->i_c; 00149 00150 float s = FastSin(theta); 00151 float c = FastCos(theta); 00152 dq0(controller->theta_elec, controller->i_a, controller->i_b, controller->i_c, &controller->i_d, &controller->i_q); //dq0 transform on currents 00153 //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 00154 //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); 00155 00156 controller->i_q_filt = 0.95f*controller->i_q_filt + 0.05f*controller->i_q; 00157 controller->i_d_filt = 0.95f*controller->i_d_filt + 0.05f*controller->i_d; 00158 00159 00160 // Filter the current references to the desired closed-loop bandwidth 00161 controller->i_d_ref_filt = (1.0f-controller->alpha)*controller->i_d_ref_filt + controller->alpha*controller->i_d_ref; 00162 controller->i_q_ref_filt = (1.0f-controller->alpha)*controller->i_q_ref_filt + controller->alpha*controller->i_q_ref; 00163 00164 00165 /// Field Weakening /// 00166 00167 controller->fw_int += .001f*(0.5f*OVERMODULATION*controller->v_bus - controller->v_ref); 00168 controller->fw_int = fmaxf(fminf(controller->fw_int, 0.0f), -I_FW_MAX); 00169 controller->i_d_ref = controller->fw_int; 00170 //float i_cmd_mag_sq = controller->i_d_ref*controller->i_d_ref + controller->i_q_ref*controller->i_q_ref; 00171 limit_norm(&controller->i_d_ref, &controller->i_q_ref, I_MAX); 00172 00173 00174 00175 /// PI Controller /// 00176 float i_d_error = controller->i_d_ref - controller->i_d; 00177 float i_q_error = controller->i_q_ref - controller->i_q;// + cogging_current; 00178 00179 // Calculate feed-forward voltages // 00180 float v_d_ff = SQRT3*(1.0f*controller->i_d_ref*R_PHASE - controller->dtheta_elec*L_Q*controller->i_q); //feed-forward voltages 00181 float v_q_ff = SQRT3*(1.0f*controller->i_q_ref*R_PHASE + controller->dtheta_elec*(L_D*controller->i_d + 1.0f*WB)); 00182 00183 // Integrate Error // 00184 controller->d_int += controller->k_d*controller->ki_d*i_d_error; 00185 controller->q_int += controller->k_q*controller->ki_q*i_q_error; 00186 00187 controller->d_int = fmaxf(fminf(controller->d_int, OVERMODULATION*controller->v_bus), - OVERMODULATION*controller->v_bus); 00188 controller->q_int = fmaxf(fminf(controller->q_int, OVERMODULATION*controller->v_bus), - OVERMODULATION*controller->v_bus); 00189 00190 //limit_norm(&controller->d_int, &controller->q_int, OVERMODULATION*controller->v_bus); 00191 controller->v_d = controller->k_d*i_d_error + controller->d_int ;//+ v_d_ff; 00192 controller->v_q = controller->k_q*i_q_error + controller->q_int ;//+ v_q_ff; 00193 00194 controller->v_ref = sqrt(controller->v_d*controller->v_d + controller->v_q*controller->v_q); 00195 00196 limit_norm(&controller->v_d, &controller->v_q, OVERMODULATION*controller->v_bus); // Normalize voltage vector to lie within curcle of radius v_bus 00197 //float dtc_d = controller->v_d/controller->v_bus; 00198 //float dtc_q = controller->v_q/controller->v_bus; 00199 //linearize_dtc(&dtc_d); 00200 //linearize_dtc(&dtc_q); 00201 //controller->v_d = dtc_d*controller->v_bus; 00202 //controller->v_q = dtc_q*controller->v_bus; 00203 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 00204 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 00205 00206 if(PHASE_ORDER){ // Check which phase order to use, 00207 TIM1->CCR3 = (PWM_ARR)*(1.0f-controller->dtc_u); // Write duty cycles 00208 TIM1->CCR2 = (PWM_ARR)*(1.0f-controller->dtc_v); 00209 TIM1->CCR1 = (PWM_ARR)*(1.0f-controller->dtc_w); 00210 } 00211 else{ 00212 TIM1->CCR3 = (PWM_ARR)*(1.0f-controller->dtc_u); 00213 TIM1->CCR1 = (PWM_ARR)*(1.0f-controller->dtc_v); 00214 TIM1->CCR2 = (PWM_ARR)*(1.0f-controller->dtc_w); 00215 } 00216 00217 controller->theta_elec = theta; 00218 00219 } 00220 00221 00222 void torque_control(ControllerStruct *controller){ 00223 float torque_ref = controller->kp*(controller->p_des - controller->theta_mech) + controller->t_ff + controller->kd*(controller->v_des - controller->dtheta_mech); 00224 //float torque_ref = -.1*(controller->p_des - controller->theta_mech); 00225 controller->i_q_ref = torque_ref/KT_OUT; 00226 controller->i_d_ref = 0.0f; 00227 } 00228
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