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PID C++ implementation
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| #ifndef _PID_SOURCE_ | |
| #define _PID_SOURCE_ | |
| #include <iostream> | |
| #include <cmath> | |
| #include "pid.h" | |
| using namespace std; | |
| class PIDImpl | |
| { | |
| public: | |
| PIDImpl( double dt, double max, double min, double Kp, double Kd, double Ki ); | |
| ~PIDImpl(); | |
| double calculate( double setpoint, double pv ); | |
| private: | |
| double _dt; | |
| double _max; | |
| double _min; | |
| double _Kp; | |
| double _Kd; | |
| double _Ki; | |
| double _pre_error; | |
| double _integral; | |
| }; | |
| PID::PID( double dt, double max, double min, double Kp, double Kd, double Ki ) | |
| { | |
| pimpl = new PIDImpl(dt,max,min,Kp,Kd,Ki); | |
| } | |
| double PID::calculate( double setpoint, double pv ) | |
| { | |
| return pimpl->calculate(setpoint,pv); | |
| } | |
| PID::~PID() | |
| { | |
| delete pimpl; | |
| } | |
| /** | |
| * Implementation | |
| */ | |
| PIDImpl::PIDImpl( double dt, double max, double min, double Kp, double Kd, double Ki ) : | |
| _dt(dt), | |
| _max(max), | |
| _min(min), | |
| _Kp(Kp), | |
| _Kd(Kd), | |
| _Ki(Ki), | |
| _pre_error(0), | |
| _integral(0) | |
| { | |
| } | |
| double PIDImpl::calculate( 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; | |
| } | |
| PIDImpl::~PIDImpl() | |
| { | |
| } | |
| #endif |
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| #ifndef _PID_H_ | |
| #define _PID_H_ | |
| class PIDImpl; | |
| class PID | |
| { | |
| public: | |
| // Kp - proportional gain | |
| // Ki - Integral gain | |
| // Kd - derivative gain | |
| // dt - loop interval time | |
| // max - maximum value of manipulated variable | |
| // min - minimum value of manipulated variable | |
| PID( double dt, double max, double min, double Kp, double Kd, double Ki ); | |
| // Returns the manipulated variable given a setpoint and current process value | |
| double calculate( double setpoint, double pv ); | |
| ~PID(); | |
| private: | |
| PIDImpl *pimpl; | |
| }; | |
| #endif |
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Hello!
As I understand it is implementation
(in Matlab)
But in matlab we have option - use derivative filter (finite N)
How to modify your solution to support this functionality?
Thx