Diff: FOC/foc.cpp

Revision:

48:74a40481740c

Parent:

47:e1196a851f76

Child:

49:83d83040ea51

--- a/FOC/foc.cpp	Wed Dec 05 04:07:46 2018 +0000
+++ b/FOC/foc.cpp	Sun Mar 03 02:51:51 2019 +0000
@@ -33,7 +33,7 @@
     /// Space Vector Modulation ///
     /// u,v,w amplitude = v_bus for full modulation depth ///
     
-    float v_offset = (fminf3(u, v, w) + fmaxf3(u, v, w))/2.0f;
+    float v_offset = (fminf3(u, v, w) + fmaxf3(u, v, w))*0.5f;
     
     *dtc_u = fminf(fmaxf(((u -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX);
     *dtc_v = fminf(fmaxf(((v -v_offset)/v_bus + .5f), DTC_MIN), DTC_MAX);
@@ -49,7 +49,19 @@
     
     }
 
-
+void linearize_dtc(float *dtc){
+    /// linearizes the output of the inverter, which is not linear for small duty cycles ///
+    float sgn = 1.0f-(2.0f*(dtc<0));
+    if(abs(*dtc) >= .01f){
+        *dtc = *dtc*.986f+.014f*sgn;
+        }
+    else{
+        *dtc = 2.5f*(*dtc);
+        }
+    
+    }
+    
+    
 void zero_current(int *offset_1, int *offset_2){                                // Measure zero-offset of the current sensors
     int adc1_offset = 0;
     int adc2_offset = 0;
@@ -92,6 +104,11 @@
 
     }
     
+void reset_observer(ObserverStruct *observer){
+    observer->temperature = 25.0f;
+    observer->resistance = .1f;
+    }
+    
 void limit_current_ref (ControllerStruct *controller){
     float i_q_max_limit = (0.5774f*controller->v_bus - controller->dtheta_elec*WB)/R_PHASE;
     float i_q_min_limit = (-0.5774f*controller->v_bus - controller->dtheta_elec*WB)/R_PHASE;
@@ -99,7 +116,24 @@
     }
 
 
-void commutate(ControllerStruct *controller, GPIOStruct *gpio, float theta){
+void commutate(ControllerStruct *controller, ObserverStruct *observer, GPIOStruct *gpio, float theta){
+        
+        /// Update observer estimates ///
+        // Resistance observer //
+        // Temperature Observer //
+        float t_rise = (float)observer->temperature - 25.0f;
+        float q_th_in = (1.0f + .00393f*t_rise)*(controller->i_d*controller->i_d*R_PHASE*1.5f + controller->i_q*controller->i_q*R_PHASE*1.5f);
+        float q_th_out = t_rise*R_TH;
+        observer->temperature += INV_M_TH*DT*(q_th_in-q_th_out);
+        
+        //observer->resistance = (controller->v_q - 2.0f*controller->dtheta_elec*(WB + L_D*controller->i_d))/controller->i_q;
+        observer->resistance = controller->v_q/controller->i_q;
+        if(isnan(observer->resistance)){observer->resistance = R_PHASE;}
+        observer->temperature2 = (double)(25.0f + ((observer->resistance*6.0606f)-1.0f)*275.5f);
+        double e = observer->temperature - observer->temperature2;
+        observer->temperature -= .001*e;
+        //printf("%.3f\n\r", e);
+        
 
        /// Commutation Loop ///
        controller->loop_count ++;   
@@ -124,32 +158,27 @@
         
         
         // Filter the current references to the desired closed-loopbandwidth
-        // Allows calculation of desired di/dt for inductance, etc
-        controller->did_dt = controller->i_d_ref_filt;
-        controller->diq_dt = controller->i_q_ref_filt;
         controller->i_d_ref_filt = (1.0f-controller->alpha)*controller->i_d_ref_filt + controller->alpha*controller->i_d_ref;
         controller->i_q_ref_filt = (1.0f-controller->alpha)*controller->i_q_ref_filt + controller->alpha*controller->i_q_ref;
-        controller->did_dt = (controller->i_d_ref_filt - controller->did_dt)/DT;
-        controller->diq_dt = (controller->i_q_ref_filt - controller->diq_dt)/DT;
+
+       
+       /// Field Weakening ///
+       
+       controller->fw_int += .001f*(0.5f*OVERMODULATION*controller->v_bus - controller->v_ref);
+       controller->fw_int = fmaxf(fminf(controller->fw_int, 0.0f), -I_MAX_FW);
+       controller->i_d_ref = controller->fw_int;
+       //float i_cmd_mag_sq = controller->i_d_ref*controller->i_d_ref + controller->i_q_ref*controller->i_q_ref;
+       limit_norm(&controller->i_d_ref, &controller->i_q_ref, I_MAX);
        
        
-       /// Field Weakening ///
-       /*
-       controller->fw_int += .001*(0.5f*OVERMODULATION*controller->v_bus - controller->v_ref);
-       controller->fw_int = fmaxf(fminf(controller->fw_int, 0.0f), -I_MAX_FW);
-       controller->i_d_ref = controller->fw_int;
-       float i_cmd_mag_sq = controller->i_d_ref*controller->i_d_ref + controller->i_q_ref*controller->i_q_ref;
-       limit_norm(&controller->i_d_ref, &controller->i_q_ref, I_MAX);
-       
-       */
        
        /// PI Controller ///
        float i_d_error = controller->i_d_ref - controller->i_d;
        float i_q_error = controller->i_q_ref - controller->i_q;//  + cogging_current;
        
        // Calculate feed-forward voltages //
-       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
-       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));
+       float v_d_ff = SQRT3*(1.0f*controller->i_d_ref*R_PHASE  - controller->dtheta_elec*L_Q*controller->i_q);   //feed-forward voltages
+       float v_q_ff =  SQRT3*(1.0f*controller->i_q_ref*R_PHASE +  controller->dtheta_elec*(L_D*controller->i_d + 1.0f*WB));
        
        // Integrate Error //
        controller->d_int += controller->k_d*controller->ki_d*i_d_error;   
@@ -165,6 +194,12 @@
        controller->v_ref = sqrt(controller->v_d*controller->v_d + controller->v_q*controller->v_q);
        
        limit_norm(&controller->v_d, &controller->v_q, OVERMODULATION*controller->v_bus);       // Normalize voltage vector to lie within curcle of radius v_bus
+       float dtc_d = controller->v_d/controller->v_bus;
+       float dtc_q = controller->v_q/controller->v_bus;
+       linearize_dtc(&dtc_d);
+       linearize_dtc(&dtc_q);
+       controller->v_d = dtc_d*controller->v_bus;
+       controller->v_q = dtc_q*controller->v_bus;
        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
        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
 
@@ -179,7 +214,7 @@
             TIM1->CCR2 =  (PWM_ARR)*(1.0f-controller->dtc_w);
         }
 
-       controller->theta_elec = theta;                                          //For some reason putting this at the front breaks thins
+       controller->theta_elec = theta;                                          
        
     }