Addition of antiwindup and negative error

Addition of an anti-windup at the end of the pid calculation to
avoid PID divergence.
Correction of the negative error calculation

Tested in V1.1.2 board 2
Buck mode
Converged in 20ms
12V step response
24V Vhigh

src/data_conversion.c

@@ -42,18 +42,18 @@
 // ADC convertions variable
 
 // ADC1
-static float32_t raw_values_adc1[4];
-static float32_t raw_values_offset_removed_adc1[4];
-static float32_t converted_values_adc1[4];
+static float32_t raw_values_adc1[4]={0};
+static float32_t raw_values_offset_removed_adc1[4]={0};
+static float32_t converted_values_adc1[4]={0};
 static float32_t gain_adc1[4] = {0.0125, 0.0107, 0.0125, 0};
 static float32_t offset_adc1[4] = {2030.88, 2029.065, 2017.68, 0};
 
 // ADC2
-static float32_t raw_values_adc2[3];
-static float32_t raw_values_offset_removed_adc2[3];
-static float32_t converted_values_adc2[3];
-static float32_t gain_adc2[3] = {0.0355, 0.0355, 0.0672};
-static float32_t offset_adc2[3] = {2012.11, 2011.74, 3.022};
+static float32_t raw_values_adc2[3]={0};
+static float32_t raw_values_offset_removed_adc2[3]={0};
+static float32_t converted_values_adc2[3]={0};
+static float32_t gain_adc2[3] = {0.0462, 0.0355, 0.0668};
+static float32_t offset_adc2[3] = {94.04, 2011.74, -4.1708};
 static float32_t gain_adc1_triple_linearization[3] = {0.0439, 0.0261, 0.0453};
 static float32_t offset_adc2_triple_linearization[3] = {2036.583, 1834.98, 2160.97};
 
@@ -61,6 +61,54 @@ static float32_t offset_adc2_triple_linearization[3] = {2036.583, 1834.98, 2160.
 /////
 // Private Functions
 
+
+/**
+ * These functions update the paramters of the variables
+ */
+void v1_low_parameters_set(float32_t gain, float32_t offset)
+{
+	gain_adc2[0] = gain;
+	offset_adc2[0] = offset;
+}
+
+void v2_low_parameters_set(float32_t gain, float32_t offset)
+{
+	gain_adc2[1] = gain;
+	offset_adc2[1] = offset;
+}
+
+void v_high_parameters_set(float32_t gain, float32_t offset)
+{
+	gain_adc2[2] = gain;
+	offset_adc2[2] = offset;
+}
+
+void i1_low_parameters_set(float32_t gain, float32_t offset)
+{
+	gain_adc1[0] = gain;
+	offset_adc1[0] = offset;
+}
+
+void i2_low_parameters_set(float32_t gain, float32_t offset)
+{
+	gain_adc1[1] = gain;
+	offset_adc1[1] = offset;
+}
+
+void i_high_parameters_set(float32_t gain, float32_t offset)
+{
+	gain_adc1[2] = gain;
+	offset_adc1[2] = offset;
+}
+
+void temp_parameters_set(float32_t gain, float32_t offset)
+{
+	gain_adc1[3] = gain;
+	offset_adc1[3] = offset;
+}
+
+
+
 /**
  * This function select the right conversion equation
  * depending of the voltage measured to solve the non linear response
@@ -85,6 +133,8 @@ void triple_linerarization(float32_t value_adc, int8_t adc_channel)
 	}
 }
 
+
+
 /////
 // Public Functions
 
@@ -94,31 +144,53 @@ void triple_linerarization(float32_t value_adc, int8_t adc_channel)
  */
 void data_conversion()
 {
-	if( (data_dispatch_get_values_available_in_adc1_channel(0)!=0) &&
-		(data_dispatch_get_values_available_in_adc1_channel(1)!=0) &&
-		(data_dispatch_get_values_available_in_adc1_channel(2)!=0) &&
-		(data_dispatch_get_values_available_in_adc2_channel(0)!=0) &&
-		(data_dispatch_get_values_available_in_adc2_channel(1)!=0) &&
-		(data_dispatch_get_values_available_in_adc2_channel(2)!=0) )
+	if( 
+		// (data_dispatch_get_values_available_in_adc1_channel(0)!=0) &&
+		// (data_dispatch_get_values_available_in_adc1_channel(1)!=0) &&
+		// (data_dispatch_get_values_available_in_adc1_channel(2)!=0) &&
+		(data_dispatch_get_values_available_in_adc2_channel(0)!=0) //&&
+		// (data_dispatch_get_values_available_in_adc2_channel(1)!=0) &&
+		// (data_dispatch_get_values_available_in_adc2_channel(2)!=0) 
+		)
 	{
 		// Data gathering from the buffer and conversion to float for PID calculation
-		raw_values_adc1[0] = (float32_t)data_dispatch_get_next_value_from_adc1_channel(0);
-		raw_values_adc1[1] = (float32_t)data_dispatch_get_next_value_from_adc1_channel(1);
-		raw_values_adc1[2] = (float32_t)data_dispatch_get_next_value_from_adc1_channel(2);
+		// raw_values_adc1[0] = (float32_t)data_dispatch_get_next_value_from_adc1_channel(0);
+		// raw_values_adc1[1] = (float32_t)data_dispatch_get_next_value_from_adc1_channel(1);
+		// raw_values_adc1[2] = (float32_t)data_dispatch_get_next_value_from_adc1_channel(2);
 		raw_values_adc2[0] = (float32_t)data_dispatch_get_next_value_from_adc2_channel(0);
-		raw_values_adc2[1] = (float32_t)data_dispatch_get_next_value_from_adc2_channel(1);
-		raw_values_adc2[2] = (float32_t)data_dispatch_get_next_value_from_adc2_channel(2);
+		// raw_values_adc2[1] = (float32_t)data_dispatch_get_next_value_from_adc2_channel(1);
+		// raw_values_adc2[2] = (float32_t)data_dispatch_get_next_value_from_adc2_channel(2);
 
+		arm_mult_f32(&raw_values_adc2[0], &gain_adc2[0], &raw_values_offset_removed_adc2[0], 1);
+		arm_sub_f32(&raw_values_offset_removed_adc2[0], &offset_adc2[0], &converted_values_adc2[0], 1);
+	}
+	if( 
+		// (data_dispatch_get_values_available_in_adc1_channel(0)!=0) &&
+		// (data_dispatch_get_values_available_in_adc1_channel(1)!=0) &&
+		// (data_dispatch_get_values_available_in_adc1_channel(2)!=0) &&
+		//(data_dispatch_get_values_available_in_adc2_channel(0)!=0) //&&
+		// (data_dispatch_get_values_available_in_adc2_channel(1)!=0) &&
+		 (data_dispatch_get_values_available_in_adc2_channel(2)!=0) 
+		)
+	{
+		// Data gathering from the buffer and conversion to float for PID calculation
+		 raw_values_adc2[2] = (float32_t)data_dispatch_get_next_value_from_adc2_channel(2);
 		// Update of the linearization depending of the value
-		triple_linerarization(raw_values_adc2[0], 0);
-		triple_linerarization(raw_values_adc2[1], 1);
+		//triple_linerarization(raw_values_adc2[0], 0);
+		//triple_linerarization(raw_values_adc2[1], 1);
 
 		// Conversion of the raw ADC value in volt and ampere
-		arm_sub_f32(raw_values_adc1, offset_adc1, raw_values_offset_removed_adc1, 4);
-		arm_sub_f32(raw_values_adc2, offset_adc2, raw_values_offset_removed_adc2, 3);
-		arm_mult_f32(raw_values_offset_removed_adc1, gain_adc1, converted_values_adc1, 4);
-		arm_mult_f32(raw_values_offset_removed_adc2, gain_adc2, converted_values_adc2, 3);
+		// arm_sub_f32(raw_values_adc1, offset_adc1, raw_values_offset_removed_adc1, 4);
+		//arm_sub_f32(&raw_values_adc2[0], &offset_adc2[0], &raw_values_offset_removed_adc2[0], 1);
+		// arm_mult_f32(raw_values_offset_removed_adc1, gain_adc1, converted_values_adc1, 4);
+		//arm_mult_f32(&raw_values_offset_removed_adc2[0], &gain_adc2[0], &converted_values_adc2[0], 1);
+		
+		arm_mult_f32(&raw_values_adc2[2], &gain_adc2[2], &raw_values_offset_removed_adc2[2], 1);
+		arm_sub_f32(&raw_values_offset_removed_adc2[2], &offset_adc2[2], &converted_values_adc2[2], 1);
+
 	}
+
+	
 }
 
 /**

src/data_conversion.h

@@ -44,6 +44,24 @@ void data_conversion();
  */
 float32_t get_value_converted(uint8_t adc_number, uint8_t adc_channel);
 
+
+void v1_low_parameters_set(float32_t gain, float32_t offset);
+
+void v2_low_parameters_set(float32_t gain, float32_t offset);
+
+void v_high_parameters_set(float32_t gain, float32_t offset);
+
+void i1_low_parameters_set(float32_t gain, float32_t offset);
+
+void i2_low_parameters_set(float32_t gain, float32_t offset);
+
+
+void i_high_parameters_set(float32_t gain, float32_t offset);
+
+void temp_parameters_set(float32_t gain, float32_t offset);
+
+
+
 #ifdef __cplusplus
 }
 #endif

src/opalib_pid.c

@@ -55,9 +55,13 @@
 
 // PID variables
 static float32_t Vref;
-static float32_t V1_value;
+static float32_t V1_value, Vhigh_value;
 static float32_t error_pid;
 static arm_pid_instance_f32 PID_variables;
+static float32_t pid_out_windUp = 0.1;     // stores the current pid output after anti windup and before saturation
+static float32_t prev_pid_out = 0.1; 	// stores the previous unsaturated output
+static float32_t pid_out;        // stores the current pid_output after saturation and anti windUp (the effective duty cycle)
+float32_t Kw = 0.000143; // WindUp Parameter
 
 // PWM variables
 static float32_t pwm_duty_cycle = 0.1; // PWM initialization value
@@ -119,28 +123,59 @@ void pid_calculation_and_pwm_update()
 
 	// PID CALCUALTIONS
 	V1_value = get_value_converted(2 , 0);
-	arm_sub_f32(&V1_value, &Vref, &error_pid, 1);		// CALCULATING THE ERROR BASED ON THE REFERENCE
-	pwm_duty_cycle = arm_pid_f32(&PID_variables, 0.01*error_pid);	        // PID CALCULATIONS
-
-	// TESTING PWM VALUE TO AVOID OVERFLOW AND PWM UPDATE//
-	if (pwm_duty_cycle > HIGH_DUTY) // SATURATION CONDITIONS TO AVOID DIVERGENCE.
+	Vhigh_value = get_value_converted(2 , 2);
+	arm_sub_f32(&Vref, &V1_value, &error_pid, 1);		// CALCULATING THE ERROR BASED ON THE REFERENCE
+	
+	if (Vhigh_value > Vref)
 	{
-		pwm_pulse_width = pwm_high_pulse_width;
-		leg_set(TIMA, pwm_pulse_width, 0);
-		leg_set(TIMB, pwm_pulse_width, pwm_phase_shift);
+		pid_out = arm_pid_f32(&PID_variables, error_pid);	        // PID CALCULATIONS
+
+		//PID anti WindUp saturation 
+		pid_out_windUp = pid_out + Kw * (pwm_duty_cycle - prev_pid_out);
+		PID_variables.state[2] = pid_out_windUp;
+		pwm_duty_cycle = pid_out_windUp;
+		prev_pid_out = pid_out;
+
+
+		// TESTING PWM VALUE TO AVOID OVERFLOW AND PWM UPDATE//
+		if (pwm_duty_cycle > HIGH_DUTY) // SATURATION CONDITIONS TO AVOID DIVERGENCE.
+		{
+			pwm_duty_cycle = HIGH_DUTY;
+			pwm_pulse_width = pwm_high_pulse_width;
+			leg_set(TIMA, pwm_pulse_width, 0);
+			leg_set(TIMB, pwm_pulse_width, pwm_phase_shift);
+		}
+
+		else if (pwm_duty_cycle < LOW_DUTY) // SATURATION CONDITIONS TO AVOID DIVERGENCE.
+		{
+			pwm_duty_cycle = LOW_DUTY;
+			pwm_pulse_width = pwm_low_pulse_width;
+			leg_set(TIMA, pwm_pulse_width, 0);
+			leg_set(TIMB, pwm_pulse_width, pwm_phase_shift);
+		}
+
+		else
+		{	
+			pwm_pulse_width = (pwm_duty_cycle * pwm_period);
+			leg_set(TIMA, pwm_pulse_width, 0);
+			leg_set(TIMB, pwm_pulse_width, pwm_phase_shift);	
+		}		
 	}
-
-	else if (pwm_duty_cycle < LOW_DUTY) // SATURATION CONDITIONS TO AVOID DIVERGENCE.
-	{
-		pwm_pulse_width = pwm_low_pulse_width;
-		leg_set(TIMA, pwm_pulse_width, 0);
-		leg_set(TIMB, pwm_pulse_width, pwm_phase_shift);
-	}
-
+	
 	else
 	{
-		pwm_pulse_width = (pwm_duty_cycle * pwm_period);
-		leg_set(TIMA, pwm_pulse_width, 0);
-		leg_set(TIMB, pwm_pulse_width, pwm_phase_shift);	
-	}		
+		arm_pid_reset_q31(&PID_variables);
+		pwm_duty_cycle = LOW_DUTY;
+		leg_set(TIMA, pwm_low_pulse_width, 0);
+		leg_set(TIMB, pwm_low_pulse_width, pwm_phase_shift);	
+	}	
 }
+
+
+void test()
+{
+	data_conversion();
+	pwm_pulse_width = (0.5 * pwm_period);
+	leg_set(TIMA, pwm_pulse_width, 0);
+	leg_set(TIMB, pwm_pulse_width, pwm_phase_shift);
+}
\ No newline at end of file

src/opalib_pid.h

@@ -59,6 +59,7 @@ void pid_init_boost(float32_t vref, float32_t kp, float32_t ki, float32_t kd);
  */
 void pid_calculation_and_pwm_update();
 
+void test();
 
 #ifdef __cplusplus
 }