Ruprecht Altenburger / Library_Cntrl2

2nd Library

PID_Cntrl.cpp@4:db615f5fa407, 2021-04-27 (annotated)

Committer:
altb2
Date:
Tue Apr 27 07:49:53 2021 +0000
Revision:
4:db615f5fa407
Parent:
0:a201a6cd4c0c 
.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
altb2 0:a201a6cd4c0c 1 /*
altb2 0:a201a6cd4c0c 2 PI Controller class with anti windup reset in biquad transposed direct form 2
altb2 0:a201a6cd4c0c 3 see e.g.: https://www.dsprelated.com/freebooks/filters/Four_Direct_Forms.html
altb2 0:a201a6cd4c0c 4 everything is calculated in double
altb2 0:a201a6cd4c0c 5
altb2 0:a201a6cd4c0c 6 Ts z - 1
altb2 0:a201a6cd4c0c 7 G(s) = P + I ------- + D ------- D corresponds Kd/Tf in Matlab-formlism pid(...)
altb2 0:a201a6cd4c0c 8 z - 1 z - p
altb2 0:a201a6cd4c0c 9 */
altb2 0:a201a6cd4c0c 10
altb2 0:a201a6cd4c0c 11 #include "PID_Cntrl.h"
altb2 0:a201a6cd4c0c 12 using namespace std;
altb2 0:a201a6cd4c0c 13
altb2 0:a201a6cd4c0c 14 PID_Cntrl::PID_Cntrl(float P, float I, float D, float tau_f, float Ts, float uMin, float uMax)
altb2 0:a201a6cd4c0c 15 {
altb2 0:a201a6cd4c0c 16 setCoefficients(P, I, D, tau_f, Ts);
altb2 0:a201a6cd4c0c 17 this->uMin = (double)uMin;
altb2 0:a201a6cd4c0c 18 this->uMax = (double)uMax;
altb2 0:a201a6cd4c0c 19 reset(0.0f);
altb2 0:a201a6cd4c0c 20 }
altb2 0:a201a6cd4c0c 21
altb2 0:a201a6cd4c0c 22 PID_Cntrl::~PID_Cntrl() {}
altb2 0:a201a6cd4c0c 23
altb2 0:a201a6cd4c0c 24 void PID_Cntrl::reset(float initValue)
altb2 0:a201a6cd4c0c 25 {
altb2 0:a201a6cd4c0c 26 Iold = (double)initValue;
altb2 0:a201a6cd4c0c 27 eold = 0.0;yold = 0.0;
altb2 0:a201a6cd4c0c 28 del = 0.0;
altb2 0:a201a6cd4c0c 29 }
altb2 0:a201a6cd4c0c 30
altb2 0:a201a6cd4c0c 31 void PID_Cntrl::setCoefficients(float P, float I, float D, float tau_f, float Ts)
altb2 0:a201a6cd4c0c 32 {
altb2 0:a201a6cd4c0c 33 this->p = 1.0 - (double)Ts/(double)tau_f;
altb2 0:a201a6cd4c0c 34 this->P = P;
altb2 0:a201a6cd4c0c 35 this->I = I;
altb2 0:a201a6cd4c0c 36 this->D = D;
altb2 0:a201a6cd4c0c 37 this->Ts = Ts;
altb2 0:a201a6cd4c0c 38 if(P!=0)
altb2 0:a201a6cd4c0c 39 this->Ka=1/P;
altb2 0:a201a6cd4c0c 40 else
altb2 0:a201a6cd4c0c 41 this->Ka=1.0f;
altb2 0:a201a6cd4c0c 42
altb2 0:a201a6cd4c0c 43 }
altb2 0:a201a6cd4c0c 44
altb2 0:a201a6cd4c0c 45 float PID_Cntrl::doStep(double e)
altb2 0:a201a6cd4c0c 46 {
altb2 0:a201a6cd4c0c 47 double Ipart = Iold+I*Ts*(e-del);
altb2 0:a201a6cd4c0c 48 double Dpart = D*(e-eold)+p*yold;
altb2 0:a201a6cd4c0c 49 double u = P*e + Dpart + Ipart; // unconstrained output
altb2 0:a201a6cd4c0c 50 double uc = u; // constrained output
altb2 0:a201a6cd4c0c 51 if(u > uMax) uc = uMax;
altb2 0:a201a6cd4c0c 52 else if(u < uMin) uc = uMin;
altb2 0:a201a6cd4c0c 53 del=(u-uc)*Ka;
altb2 0:a201a6cd4c0c 54 eold=e;
altb2 0:a201a6cd4c0c 55 Iold=Ipart;
altb2 0:a201a6cd4c0c 56 yold=Dpart;
altb2 0:a201a6cd4c0c 57 return (float)uc;
altb2 0:a201a6cd4c0c 58 }
altb2 0:a201a6cd4c0c 59
altb2 0:a201a6cd4c0c 60 void PID_Cntrl::set_limits(double ll, double ul)
altb2 0:a201a6cd4c0c 61 {
altb2 0:a201a6cd4c0c 62 this->uMin = (double)ll;
altb2 0:a201a6cd4c0c 63 this->uMax = (double)ul;
altb2 0:a201a6cd4c0c 64 }
altb2 0:a201a6cd4c0c 65
altb2 0:a201a6cd4c0c 66 float PID_Cntrl::get_ulimit(void)
altb2 0:a201a6cd4c0c 67 {
altb2 0:a201a6cd4c0c 68 return (float)this->uMax;
altb2 0:a201a6cd4c0c 69 }