ardupilot/libraries/AP_PID/AP_PID.h

56 lines
1.3 KiB
C++

// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: t -*-
/// @file AP_PID.h
/// @brief Generic PID algorithm, with EEPROM-backed storage of constants.
#ifndef AP_PID_h
#define AP_PID_h
#include <AP_Common.h>
#include <math.h> // for fabs()
/// @class AP_PID
/// @brief Object managing one PID control
class AP_PID {
public:
AP_PID();
long get_pid(int32_t error, uint16_t dt, float scaler = 1.0);
/// Reset the PID integrator
///
void reset_I();
void kP(const float v) { _kp = v; }
void kI(const float v) { _ki = v; }
void kD(const float v) { _kd = v; }
void imax(const int16_t v) { _imax = v; }
float kP() { return _kp; }
float kI() { return _ki; }
float kD() { return _kd; }
float imax() { return _imax; }
float get_integrator() const { return _integrator; }
private:
float _kp;
float _ki;
float _kd;
float _imax;
float _integrator; ///< integrator value
int32_t _last_error; ///< last error for derivative
float _last_derivative; ///< last derivative for low-pass filter
/// Low pass filter cut frequency for derivative calculation.
///
/// 20 Hz becasue anything over that is probably noise, see
/// http://en.wikipedia.org/wiki/Low-pass_filter.
///
static const uint8_t _fCut = 20;
};
#endif