altb_pmic / Lib_Cntrl

Control Library by altb

Dependents:   My_Libraries IndNav_QK3_T265

PID_Cntrl.cpp@3:27595dd9e433, 2019-07-05 (annotated)

Committer:
altb2
Date:
Fri Jul 05 06:56:49 2019 +0000
Revision:
3:27595dd9e433
Parent:
2:e7c9e50a2e46
Child:
5:d8c53cece01b
D-Anteil umparametriert, so dass konsistent mit Matlab!!!

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
altb2 2:e7c9e50a2e46 4 everything is calculated in float
altb 0:d49418189c5c 5
altb2 2:e7c9e50a2e46 6 Ts z - 1
altb2 2:e7c9e50a2e46 7 G(s) = P + I ------- + D/tau ------- D corresponds Kd in Matlab-formlism pid(...)
altb2 2:e7c9e50a2e46 8 z - 1 z - p
altb 0:d49418189c5c 9 */
altb 0:d49418189c5c 10
altb 0:d49418189c5c 11 #include "PID_Cntrl.h"
altb 0:d49418189c5c 12 using namespace std;
altb 0:d49418189c5c 13
altb 0:d49418189c5c 14 PID_Cntrl::PID_Cntrl(float P, float I, float D, float tau_f, float Ts, float uMin, float uMax)
altb 0:d49418189c5c 15 {
altb 0:d49418189c5c 16 setCoefficients(P, I, D, tau_f, Ts);
altb2 2:e7c9e50a2e46 17 this->uMin = uMin;
altb2 2:e7c9e50a2e46 18 this->uMax = uMax;
altb 0:d49418189c5c 19 reset(0.0f);
altb 0:d49418189c5c 20 }
altb 0:d49418189c5c 21
altb 0:d49418189c5c 22 PID_Cntrl::~PID_Cntrl() {}
altb 0:d49418189c5c 23
altb 0:d49418189c5c 24 void PID_Cntrl::reset(float initValue)
altb 0:d49418189c5c 25 {
altb2 2:e7c9e50a2e46 26 Iold = initValue;
altb 0:d49418189c5c 27 eold = 0.0;yold = 0.0;
altb 0:d49418189c5c 28 del = 0.0;
altb 0:d49418189c5c 29 }
altb 0:d49418189c5c 30
altb 0:d49418189c5c 31 void PID_Cntrl::setCoefficients(float P, float I, float D, float tau_f, float Ts)
altb 0:d49418189c5c 32 {
altb2 2:e7c9e50a2e46 33 this->p = 1.0 - Ts/tau_f;
altb 0:d49418189c5c 34 this->P = P;
altb 0:d49418189c5c 35 this->I = I;
altb2 3:27595dd9e433 36 this->tau_f = tau_f;
altb2 2:e7c9e50a2e46 37 this->D_ = D/tau_f; // modified D, now D is consistent with Matlab PID
altb 0:d49418189c5c 38 this->Ts = Ts;
altb 0:d49418189c5c 39 if(P!=0)
altb 0:d49418189c5c 40 this->Ka=1/P;
altb 0:d49418189c5c 41 else
altb 0:d49418189c5c 42 this->Ka=1.0f;
altb 0:d49418189c5c 43
altb 0:d49418189c5c 44 }
altb2 3:27595dd9e433 45 void PID_Cntrl::setCoeff_P(float P)
altb2 3:27595dd9e433 46 {
altb2 3:27595dd9e433 47 this->P = P;
altb2 3:27595dd9e433 48 }
altb2 3:27595dd9e433 49 void PID_Cntrl::setCoeff_I(float I)
altb2 3:27595dd9e433 50 {
altb2 3:27595dd9e433 51 this->I = I;
altb2 3:27595dd9e433 52 }
altb2 3:27595dd9e433 53 void PID_Cntrl::setCoeff_D(float D)
altb2 3:27595dd9e433 54 {
altb2 3:27595dd9e433 55 this->D_ = D/this->tau_f;
altb2 3:27595dd9e433 56 }
altb 0:d49418189c5c 57
altb2 2:e7c9e50a2e46 58 float PID_Cntrl::doStep(float e)
altb 0:d49418189c5c 59 {
altb2 2:e7c9e50a2e46 60 float Ipart = Iold+I*Ts*(e-del);
altb2 2:e7c9e50a2e46 61 float Dpart = D_*(e-eold)+p*yold;
altb2 2:e7c9e50a2e46 62 float u = P*e + Dpart + Ipart; // unconstrained output
altb2 2:e7c9e50a2e46 63 float uc = u; // constrained output
altb 0:d49418189c5c 64 if(u > uMax) uc = uMax;
altb 0:d49418189c5c 65 else if(u < uMin) uc = uMin;
altb 0:d49418189c5c 66 del=(u-uc)*Ka;
altb 0:d49418189c5c 67 eold=e;
altb 0:d49418189c5c 68 Iold=Ipart;
altb 0:d49418189c5c 69 yold=Dpart;
altb2 2:e7c9e50a2e46 70 return uc;
altb 0:d49418189c5c 71 }
altb 0:d49418189c5c 72
altb2 2:e7c9e50a2e46 73 void PID_Cntrl::set_limits(float ll, float ul)
altb 0:d49418189c5c 74 {
altb2 2:e7c9e50a2e46 75 this->uMin = ll;
altb2 2:e7c9e50a2e46 76 this->uMax = ul;
altb 0:d49418189c5c 77 }
altb 0:d49418189c5c 78
altb 0:d49418189c5c 79 float PID_Cntrl::get_ulimit(void)
altb 0:d49418189c5c 80 {
altb2 2:e7c9e50a2e46 81 return this->uMax;
altb 0:d49418189c5c 82 }