altb_pmic / Lib_Cntrl

Control Library by altb

Dependents:   My_Libraries IndNav_QK3_T265

PI_Cntrl.cpp@15:c70cad2f4e64, 2020-01-16 (annotated)

Committer:
pmic
Date:
Thu Jan 16 09:12:50 2020 +0000
Revision:
15:c70cad2f4e64
Parent:
0:d49418189c5c 
Revisit IIR_filter.h and IIR_filter.cpp. Change internal double to float arithmetic.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
altb 0:d49418189c5c 1 /*
altb 0:d49418189c5c 2 PI Controller class with anti windup reset in biquad transposed direct form 2
altb 0:d49418189c5c 3 see e.g.: https://www.dsprelated.com/freebooks/filters/Four_Direct_Forms.html
altb 0:d49418189c5c 4 everything is calculated in double
altb 0:d49418189c5c 5
altb 0:d49418189c5c 6 Tn*s + 1
altb 0:d49418189c5c 7 G(s) = Kp ------------- with s ~ (1 - z^-1)/Ts
altb 0:d49418189c5c 8 Ts*s
altb 0:d49418189c5c 9 */
altb 0:d49418189c5c 10
altb 0:d49418189c5c 11 #include "PI_Cntrl.h"
altb 0:d49418189c5c 12
altb 0:d49418189c5c 13 using namespace std;
altb 0:d49418189c5c 14
altb 0:d49418189c5c 15 PI_Cntrl::PI_Cntrl(float Kp, float Tn, float Ts)
altb 0:d49418189c5c 16 {
altb 0:d49418189c5c 17 setCoefficients(Kp, Tn, Ts);
altb 0:d49418189c5c 18 uMax = 10000000000.0;
altb 0:d49418189c5c 19 uMin = -uMax;
altb 0:d49418189c5c 20 reset(0.0f);
altb 0:d49418189c5c 21 }
altb 0:d49418189c5c 22
altb 0:d49418189c5c 23 PI_Cntrl::PI_Cntrl(float Kp, float Tn, float Ts, float uMax)
altb 0:d49418189c5c 24 {
altb 0:d49418189c5c 25 setCoefficients(Kp, Tn, Ts);
altb 0:d49418189c5c 26 this->uMax = (double)uMax;
altb 0:d49418189c5c 27 uMin = -(double)uMax;
altb 0:d49418189c5c 28 reset(0.0f);
altb 0:d49418189c5c 29 }
altb 0:d49418189c5c 30
altb 0:d49418189c5c 31 PI_Cntrl::PI_Cntrl(float Kp, float Tn, float Ts, float uMax, float uMin)
altb 0:d49418189c5c 32 {
altb 0:d49418189c5c 33 setCoefficients(Kp, Tn, Ts);
altb 0:d49418189c5c 34 this->uMax = (double)uMax;
altb 0:d49418189c5c 35 this->uMin = (double)uMin;
altb 0:d49418189c5c 36 reset(0.0f);
altb 0:d49418189c5c 37 }
altb 0:d49418189c5c 38
altb 0:d49418189c5c 39 PI_Cntrl::~PI_Cntrl() {}
altb 0:d49418189c5c 40
altb 0:d49418189c5c 41 void PI_Cntrl::reset(float initValue)
altb 0:d49418189c5c 42 {
altb 0:d49418189c5c 43 s = (double)initValue;
altb 0:d49418189c5c 44 }
altb 0:d49418189c5c 45
altb 0:d49418189c5c 46 void PI_Cntrl::setCoefficients(float Kp, float Tn, float Ts)
altb 0:d49418189c5c 47 {
altb 0:d49418189c5c 48 b0 = (double)Kp*(1.0 + (double)Ts/(double)Tn);
altb 0:d49418189c5c 49 b1 = -(double)Kp;
altb 0:d49418189c5c 50 b2 = (double)Ts/(double)Tn;
altb 0:d49418189c5c 51 }
altb 0:d49418189c5c 52
altb 0:d49418189c5c 53 float PI_Cntrl::doStep(double e)
altb 0:d49418189c5c 54 {
altb 0:d49418189c5c 55 double u = b0*e + s; // unconstrained output
altb 0:d49418189c5c 56 double uc = u; // constrained output
altb 0:d49418189c5c 57 if(u > uMax) uc = uMax;
altb 0:d49418189c5c 58 else if(u < uMin) uc = uMin;
altb 0:d49418189c5c 59 s = b1*e + u - b2*(u - uc);
altb 0:d49418189c5c 60 return (float)uc;
altb 0:d49418189c5c 61 }