foc.cpp

00001 /* -----
00002 移除速度控制，把位置控制改成PID
00003 
00004 log file:
00005 11/05: 把現在的控制架構改成PID(torque_control)
00006 ----- */
00007 
00008 
00009 #include "foc.h"
00010 
00011 //#define POS_MAX 6.283185f //359.9999 deg
00012 using namespace FastMath;
00013 
00014 
00015 void abc( float theta, float d, float q, float *a, float *b, float *c){
00016     /// Inverse DQ0 Transform ///
00017     ///Phase current amplitude = lengh of dq vector///
00018     ///i.e. iq = 1, id = 0, peak phase current of 1///
00019     float cf = FastCos(theta);
00020     float sf = FastSin(theta);
00021     
00022     *a = cf*d - sf*q;                // Faster Inverse DQ0 transform
00023     *b = (0.86602540378f*sf-.5f*cf)*d - (-0.86602540378f*cf-.5f*sf)*q;
00024     *c = (-0.86602540378f*sf-.5f*cf)*d - (0.86602540378f*cf-.5f*sf)*q;
00025     }
00026     
00027     
00028 void dq0(float theta, float a, float b, float c, float *d, float *q){
00029     /// DQ0 Transform ///
00030     ///Phase current amplitude = lengh of dq vector///
00031     ///i.e. iq = 1, id = 0, peak phase current of 1///
00032     
00033     float cf = FastCos(theta);
00034     float sf = FastSin(theta);
00035     
00036     *d = 0.6666667f*(cf*a + (0.86602540378f*sf-.5f*cf)*b + (-0.86602540378f*sf-.5f*cf)*c);   ///Faster DQ0 Transform
00037     *q = 0.6666667f*(-sf*a - (-0.86602540378f*cf-.5f*sf)*b - (0.86602540378f*cf-.5f*sf)*c);
00038        
00039     }
00040     
00041 void svm(float v_bus, float u, float v, float w, float *dtc_u, float *dtc_v, float *dtc_w){
00042     /// Space Vector Modulation ///
00043     /// u,v,w amplitude = v_bus for full modulation depth ///
00044     
00045     float v_offset = (fminf3(u, v, w) + fmaxf3(u, v, w))*0.5f;
00046     
00047     *dtc_u = fminf(fmaxf(((u -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX);
00048     *dtc_v = fminf(fmaxf(((v -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX);
00049     *dtc_w = fminf(fmaxf(((w -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX); 
00050     
00051     /*
00052     sinusoidal pwm
00053     *dtc_u = fminf(fmaxf((u/v_bus + .5f), DTC_MIN), DTC_MAX);
00054     *dtc_v = fminf(fmaxf((v/v_bus + .5f), DTC_MIN), DTC_MAX);
00055     *dtc_w = fminf(fmaxf((w/v_bus + .5f), DTC_MIN), DTC_MAX);
00056     */
00057      
00058     
00059     }
00060 
00061 void linearize_dtc(float *dtc){
00062     /// linearizes the output of the inverter, which is not linear for small duty cycles ///
00063     float sgn = 1.0f-(2.0f*(dtc<0));
00064     if(abs(*dtc) >= .01f){
00065         *dtc = *dtc*.986f+.014f*sgn;
00066         }
00067     else{
00068         *dtc = 2.5f*(*dtc);
00069         }
00070     
00071     }
00072     
00073     
00074 void zero_current(int *offset_1, int *offset_2){                                // Measure zero-offset of the current sensors
00075     int adc1_offset = 0;
00076     int adc2_offset = 0;
00077     int n = 1024;
00078     for (int i = 0; i<n; i++){                                                  // Average n samples of the ADC
00079         TIM1->CCR3 = (PWM_ARR>>1)*(1.0f);                                               // Write duty cycles
00080         TIM1->CCR2 = (PWM_ARR>>1)*(1.0f);
00081         TIM1->CCR1 = (PWM_ARR>>1)*(1.0f);
00082         ADC1->CR2  |= 0x40000000;                                               // Begin sample and conversion
00083         wait(.001);
00084         adc2_offset += ADC2->DR;
00085         adc1_offset += ADC1->DR;
00086         }
00087     *offset_1 = adc1_offset/n;
00088     *offset_2 = adc2_offset/n;
00089     }
00090     
00091 void init_controller_params(ControllerStruct *controller){
00092     controller->ki_d = KI_D;
00093     controller->ki_q = KI_Q;
00094     controller->k_d = K_SCALE*I_BW;
00095     controller->k_q = K_SCALE*I_BW;
00096     controller->alpha = 1.0f - 1.0f/(1.0f - DT*I_BW*2.0f*PI);
00097     
00098     }
00099 
00100 void reset_foc(ControllerStruct *controller){
00101     TIM1->CCR3 = (PWM_ARR>>1)*(0.5f);
00102     TIM1->CCR1 = (PWM_ARR>>1)*(0.5f);
00103     TIM1->CCR2 = (PWM_ARR>>1)*(0.5f);
00104     controller->i_d_ref = 0;
00105     controller->i_q_ref = 0;
00106     controller->i_d = 0;
00107     controller->i_q = 0;
00108     controller->i_q_filt = 0;
00109     controller->q_int = 0;
00110     controller->d_int = 0;
00111     controller->v_q = 0;
00112     controller->v_d = 0;
00113 
00114     }
00115     
00116 void reset_observer(ObserverStruct *observer){
00117     observer->temperature = 25.0f;
00118     observer->resistance = .1f;
00119     }
00120     
00121 void limit_current_ref (ControllerStruct *controller){
00122     float i_q_max_limit = (0.5774f*controller->v_bus - controller->dtheta_elec*WB)/R_PHASE;
00123     float i_q_min_limit = (-0.5774f*controller->v_bus - controller->dtheta_elec*WB)/R_PHASE;
00124     controller->i_q_ref = fmaxf(fminf(i_q_max_limit, controller->i_q_ref), i_q_min_limit);
00125     }
00126 
00127 
00128 void commutate(ControllerStruct *controller, ObserverStruct *observer, GPIOStruct *gpio, float theta){
00129         
00130         /// Update observer estimates ///
00131         // Resistance observer //
00132         // Temperature Observer //
00133         float t_rise = (float)observer->temperature - 25.0f;
00134         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);
00135         float q_th_out = t_rise*R_TH;
00136         observer->temperature += INV_M_TH*DT*(q_th_in-q_th_out);
00137         
00138         observer->resistance = (controller->v_q - SQRT3*controller->dtheta_elec*(WB))/controller->i_q;
00139         //observer->resistance = controller->v_q/controller->i_q;
00140         if(isnan(observer->resistance)){observer->resistance = R_PHASE;}
00141         observer->temperature2 = (double)(25.0f + ((observer->resistance*6.0606f)-1.0f)*275.5f);
00142         double e = observer->temperature - observer->temperature2;
00143         observer->temperature -= .001*e;
00144         //printf("%.3f\n\r", e);
00145         
00146 
00147        /// Commutation Loop ///
00148        controller->loop_count ++;   
00149        if(PHASE_ORDER){                                                                          // Check current sensor ordering
00150            controller->i_b = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset);    // Calculate phase currents from ADC readings
00151            controller->i_c = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset);
00152            }
00153         else{
00154             controller->i_b = I_SCALE*(float)(controller->adc1_raw - controller->adc1_offset);    
00155            controller->i_c = I_SCALE*(float)(controller->adc2_raw - controller->adc2_offset);
00156            }
00157        controller->i_a = -controller->i_b - controller->i_c;       
00158        
00159        float s = FastSin(theta); 
00160        float c = FastCos(theta);                            
00161        dq0(controller->theta_elec, controller->i_a, controller->i_b, controller->i_c, &controller->i_d, &controller->i_q);    //dq0 transform on currents
00162        //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
00163        //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);
00164         
00165         controller->i_q_filt = 0.95f*controller->i_q_filt + 0.05f*controller->i_q;
00166         controller->i_d_filt = 0.95f*controller->i_d_filt + 0.05f*controller->i_d;
00167         
00168         
00169         // Filter the current references to the desired closed-loop bandwidth
00170         controller->i_d_ref_filt = (1.0f-controller->alpha)*controller->i_d_ref_filt + controller->alpha*controller->i_d_ref;
00171         controller->i_q_ref_filt = (1.0f-controller->alpha)*controller->i_q_ref_filt + controller->alpha*controller->i_q_ref;
00172 
00173        
00174        /// Field Weakening ///
00175        
00176        controller->fw_int += .001f*(0.5f*OVERMODULATION*controller->v_bus - controller->v_ref);
00177        controller->fw_int = fmaxf(fminf(controller->fw_int, 0.0f), -I_FW_MAX);
00178        controller->i_d_ref = controller->fw_int;
00179        //float i_cmd_mag_sq = controller->i_d_ref*controller->i_d_ref + controller->i_q_ref*controller->i_q_ref;
00180        limit_norm(&controller->i_d_ref, &controller->i_q_ref, I_MAX);
00181        
00182        
00183        
00184        /// PI Controller ///
00185        float i_d_error = controller->i_d_ref - controller->i_d;
00186        float i_q_error = controller->i_q_ref - controller->i_q;//  + cogging_current;
00187        
00188        // Calculate feed-forward voltages //
00189        float v_d_ff = SQRT3*(1.0f*controller->i_d_ref*R_PHASE  - controller->dtheta_elec*L_Q*controller->i_q);   //feed-forward voltages
00190        float v_q_ff =  SQRT3*(1.0f*controller->i_q_ref*R_PHASE +  controller->dtheta_elec*(L_D*controller->i_d + 1.0f*WB));
00191        
00192        // Integrate Error //
00193        controller->d_int += controller->k_d*controller->ki_d*i_d_error;   
00194        controller->q_int += controller->k_q*controller->ki_q*i_q_error;
00195        
00196        controller->d_int = fmaxf(fminf(controller->d_int, OVERMODULATION*controller->v_bus), - OVERMODULATION*controller->v_bus);
00197        controller->q_int = fmaxf(fminf(controller->q_int, OVERMODULATION*controller->v_bus), - OVERMODULATION*controller->v_bus); 
00198        
00199        //limit_norm(&controller->d_int, &controller->q_int, OVERMODULATION*controller->v_bus);     
00200        controller->v_d = controller->k_d*i_d_error + controller->d_int ;//+ v_d_ff;  
00201        controller->v_q = controller->k_q*i_q_error + controller->q_int ;//+ v_q_ff; 
00202        
00203        controller->v_ref = sqrt(controller->v_d*controller->v_d + controller->v_q*controller->v_q);
00204        
00205        limit_norm(&controller->v_d, &controller->v_q, OVERMODULATION*controller->v_bus);       // Normalize voltage vector to lie within curcle of radius v_bus
00206        //float dtc_d = controller->v_d/controller->v_bus;
00207        //float dtc_q = controller->v_q/controller->v_bus;
00208        //linearize_dtc(&dtc_d);
00209        //linearize_dtc(&dtc_q);
00210        //controller->v_d = dtc_d*controller->v_bus;
00211        //controller->v_q = dtc_q*controller->v_bus;
00212        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
00213        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
00214 
00215        if(PHASE_ORDER){                                                         // Check which phase order to use, 
00216             TIM1->CCR3 = (PWM_ARR)*(1.0f-controller->dtc_u);                        // Write duty cycles
00217             TIM1->CCR2 = (PWM_ARR)*(1.0f-controller->dtc_v);
00218             TIM1->CCR1 = (PWM_ARR)*(1.0f-controller->dtc_w);
00219         }
00220         else{
00221             TIM1->CCR3 = (PWM_ARR)*(1.0f-controller->dtc_u);
00222             TIM1->CCR1 = (PWM_ARR)*(1.0f-controller->dtc_v);
00223             TIM1->CCR2 =  (PWM_ARR)*(1.0f-controller->dtc_w);
00224         }
00225 
00226        controller->theta_elec = theta;                                          
00227        
00228     }
00229     
00230     
00231 void torque_control(ControllerStruct *controller){
00232     /*----- convert theta_mech to 0~359.9999deg -----*/
00233     static float pos, round;
00234     pos = controller->theta_mech;
00235     modf(pos/(2*PI),&round);
00236     pos = pos - round*2*PI;
00237     if(abs(pos) <= 0.001)
00238         pos = abs(pos);
00239     else if(pos < 0)
00240         pos = pos + 2*PI;
00241     /*-----------------------------------------------*/
00242     
00243     /*----- position PID control -----*/
00244     static float in_err = 0, err = 0; //integral of position error
00245     if(controller->p_des < pos)
00246         if((controller->p_des + 2*PI - pos) < (pos - controller->p_des))
00247             err = 2*PI - pos + controller->p_des;
00248         else
00249             err = controller->p_des - pos;
00250     else
00251         if((pos + 2*PI - controller->p_des) < (controller->p_des - pos))
00252             err = controller->p_des - 2*PI - pos;
00253         else
00254             err = controller->p_des - pos;
00255     
00256     in_err = in_err + err;
00257     /*
00258     err = controller->p_des - pos;
00259     in_err = in_err + err;
00260     */
00261     float torque_ref = controller->kp*(err) + controller->t_ff + controller->ki*(in_err) + controller->kd*(-controller->dtheta_mech);
00262     /*--------------------------------*/        
00263     
00264     //float torque_ref = controller->kp*(controller->p_des - controller->theta_mech) + controller->t_ff + controller->kd*(controller->v_des - controller->dtheta_mech);
00265     //float torque_ref = -.1*(controller->p_des - controller->theta_mech);
00266     controller->i_q_ref = torque_ref/KT_OUT;    
00267     controller->i_d_ref = 0.0f;
00268     }
00269