76 lines
2.1 KiB
C++
76 lines
2.1 KiB
C++
/**
|
|
* Copyright 2019 Bradley J. Snyder <snyder.bradleyj@gmail.com>
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
|
|
#include <iostream>
|
|
#include <cmath>
|
|
#include "pid.hpp"
|
|
|
|
using namespace std;
|
|
using namespace sim::util;
|
|
|
|
|
|
/**
|
|
* Implementation
|
|
*/
|
|
PID::PID( double max, double min, double Kp, double Ki, double Kd ) :
|
|
_max(max),
|
|
_min(min),
|
|
_Kp(Kp),
|
|
_Kd(Kd),
|
|
_Ki(Ki),
|
|
_pre_error(0),
|
|
_integral(0)
|
|
{
|
|
}
|
|
|
|
double PID::calculate( double dt, double setpoint, double pv )
|
|
{
|
|
// Calculate error
|
|
double error = setpoint - pv;
|
|
|
|
// Proportional term
|
|
double Pout = _Kp * error;
|
|
|
|
// Integral term
|
|
_integral += error * dt;
|
|
double Iout = _Ki * _integral;
|
|
|
|
// Derivative term
|
|
double derivative = (error - _pre_error) / dt;
|
|
double Dout = _Kd * derivative;
|
|
|
|
// Calculate total output
|
|
double output = Pout + Iout + Dout;
|
|
|
|
// Restrict to max/min
|
|
if( output > _max )
|
|
output = _max;
|
|
else if( output < _min )
|
|
output = _min;
|
|
|
|
// Save error to previous error
|
|
_pre_error = error;
|
|
|
|
return output;
|
|
}
|
|
|