mirror of https://github.com/ArduPilot/ardupilot
98 lines
3.8 KiB
C++
98 lines
3.8 KiB
C++
/// @file AC_HELI_PID.cpp
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/// @brief Generic PID algorithm
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#include <AP_Math/AP_Math.h>
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#include "AC_HELI_PID.h"
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const AP_Param::GroupInfo AC_HELI_PID::var_info[] = {
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// @Param: P
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// @DisplayName: PID Proportional Gain
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// @Description: P Gain which produces an output value that is proportional to the current error value
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AP_GROUPINFO("P", 0, AC_HELI_PID, _kp, 0),
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// @Param: I
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// @DisplayName: PID Integral Gain
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// @Description: I Gain which produces an output that is proportional to both the magnitude and the duration of the error
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AP_GROUPINFO("I", 1, AC_HELI_PID, _ki, 0),
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// @Param: D
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// @DisplayName: PID Derivative Gain
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// @Description: D Gain which produces an output that is proportional to the rate of change of the error
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AP_GROUPINFO("D", 2, AC_HELI_PID, _kd, 0),
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// 3 was for uint16 IMAX
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// @Param: FF
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// @DisplayName: FF FeedForward Gain
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// @Description: FF Gain which produces an output value that is proportional to the demanded input
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AP_GROUPINFO("FF", 4, AC_HELI_PID, _kff, 0),
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// @Param: IMAX
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// @DisplayName: PID Integral Maximum
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// @Description: The maximum/minimum value that the I term can output
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AP_GROUPINFO("IMAX", 5, AC_HELI_PID, _kimax, 0),
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// 6 was for float FILT
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// @Param: ILMI
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// @DisplayName: I-term Leak Minimum
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// @Description: Point below which I-term will not leak down
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// @Range: 0 1
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// @User: Advanced
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AP_GROUPINFO("ILMI", 7, AC_HELI_PID, _leak_min, AC_PID_LEAK_MIN),
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// 8 was for float AFF
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// @Param: FLTT
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// @DisplayName: PID Target filter frequency in Hz
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// @Description: Target filter frequency in Hz
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// @Units: Hz
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AP_GROUPINFO("FLTT", 9, AC_HELI_PID, _filt_T_hz, AC_PID_TFILT_HZ_DEFAULT),
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// @Param: FLTE
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// @DisplayName: PID Error filter frequency in Hz
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// @Description: Error filter frequency in Hz
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// @Units: Hz
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AP_GROUPINFO("FLTE", 10, AC_HELI_PID, _filt_E_hz, AC_PID_EFILT_HZ_DEFAULT),
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// @Param: FLTD
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// @DisplayName: PID D term filter frequency in Hz
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// @Description: Derivative filter frequency in Hz
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// @Units: Hz
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AP_GROUPINFO("FLTD", 11, AC_HELI_PID, _filt_D_hz, AC_PID_DFILT_HZ_DEFAULT),
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// @Param: SMAX
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// @DisplayName: Slew rate limit
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// @Description: Sets an upper limit on the slew rate produced by the combined P and D gains. If the amplitude of the control action produced by the rate feedback exceeds this value, then the D+P gain is reduced to respect the limit. This limits the amplitude of high frequency oscillations caused by an excessive gain. The limit should be set to no more than 25% of the actuators maximum slew rate to allow for load effects. Note: The gain will not be reduced to less than 10% of the nominal value. A value of zero will disable this feature.
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// @Range: 0 200
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// @Increment: 0.5
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// @User: Advanced
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AP_GROUPINFO("SMAX", 12, AC_HELI_PID, _slew_rate_max, 0),
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AP_GROUPEND
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};
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/// Constructor for PID
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AC_HELI_PID::AC_HELI_PID(float initial_p, float initial_i, float initial_d, float initial_ff, float initial_imax, float initial_filt_T_hz, float initial_filt_E_hz, float initial_filt_D_hz) :
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AC_PID(initial_p, initial_i, initial_d, initial_ff, initial_imax, initial_filt_T_hz, initial_filt_E_hz, initial_filt_D_hz)
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{
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_last_requested_rate = 0;
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}
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// This is an integrator which tends to decay to zero naturally
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// if the error is zero.
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void AC_HELI_PID::update_leaky_i(float leak_rate)
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{
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if (!is_zero(_ki)){
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// integrator does not leak down below Leak Min
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if (_integrator > _leak_min){
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_integrator -= (float)(_integrator - _leak_min) * leak_rate;
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} else if (_integrator < -_leak_min) {
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_integrator -= (float)(_integrator + _leak_min) * leak_rate;
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}
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}
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}
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