File content as of revision 7:cb1492f4f2c6:

/*  
    DT1 Controller class 
    everything is calculated in float
    
                     z - 1             
      G(s) = Kd/tau -------          D corresponds Kd in Matlab-formlism pid(...)
                     z - p              
*/

#include "DT1_Cntrl.h"
using namespace std;

DT1_Cntrl::DT1_Cntrl(float D, float tau_f, float Ts, float uMin, float uMax)
{
    setCoefficients(D, tau_f, Ts);
    this->uMin = uMin;
    this->uMax = uMax;
    reset(0.0f);
}

DT1_Cntrl::~DT1_Cntrl() {}

void DT1_Cntrl::reset(float initValue)
{
    eold = initValue;
    yold = 0.0;
}

void DT1_Cntrl::setCoefficients(float D, float tau_f, float Ts)
{
    this->p = 1.0 - Ts/tau_f;
    this->tau_f = tau_f;
    this->D_ = D/tau_f;             // modified D, now D is consistent with Matlab PID
    this->D__init = D/tau_f;        // modified D, now D is consistent with Matlab PID
    this->Ts = Ts;
}
void DT1_Cntrl::setCoeff_D(float D)
{
    this->D_ = D/this->tau_f;
}

float DT1_Cntrl::doStep(float e)
{
    float Dpart = D_*(e-eold)+p*yold;
    if(Dpart > uMax) Dpart = uMax;
    else if(Dpart < uMin) Dpart = uMin;
    return Dpart;
}

void DT1_Cntrl::set_limits(float ll, float ul)
{
    this->uMin = ll;
    this->uMax = ul;
}