CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutSign UpSign In
Ardupilot

Real-time collaboration for Jupyter Notebooks, Linux Terminals, LaTeX, VS Code, R IDE, and more,
all in one place. Commercial Alternative to JupyterHub.

GitHub Repository: Ardupilot/ardupilot
 Path: blob/master/libraries/AC_PID/AC_HELI_PID.cpp
Views: 1798
1
/// @file	AC_HELI_PID.cpp

2
/// @brief	Generic PID algorithm

3


4
#include <AP_Math/AP_Math.h>

5
#include "AC_HELI_PID.h"

6


7
const AP_Param::GroupInfo AC_HELI_PID::var_info[] = {

8
    // @Param: P

9
    // @DisplayName: PID Proportional Gain

10
    // @Description: P Gain which produces an output value that is proportional to the current error value

11
    AP_GROUPINFO("P",    0, AC_HELI_PID, _kp, 0),

12


13
    // @Param: I

14
    // @DisplayName: PID Integral Gain

15
    // @Description: I Gain which produces an output that is proportional to both the magnitude and the duration of the error

16
    AP_GROUPINFO("I",    1, AC_HELI_PID, _ki, 0),

17


18
    // @Param: D

19
    // @DisplayName: PID Derivative Gain

20
    // @Description: D Gain which produces an output that is proportional to the rate of change of the error

21
    AP_GROUPINFO("D",    2, AC_HELI_PID, _kd, 0),

22


23
    // 3 was for uint16 IMAX

24


25
    // @Param: FF

26
    // @DisplayName: FF FeedForward Gain

27
    // @Description: FF Gain which produces an output value that is proportional to the demanded input

28
    AP_GROUPINFO("FF",    4, AC_HELI_PID, _kff, 0),

29


30
    // @Param: IMAX

31
    // @DisplayName: PID Integral Maximum

32
    // @Description: The maximum/minimum value that the I term can output

33
    AP_GROUPINFO("IMAX", 5, AC_HELI_PID, _kimax, 0),

34


35
    // 6 was for float FILT

36


37
    // @Param: ILMI

38
    // @DisplayName: I-term Leak Minimum

39
    // @Description: Point below which I-term will not leak down

40
    // @Range: 0 1

41
    // @User: Advanced

42
    AP_GROUPINFO("ILMI", 7, AC_HELI_PID, _leak_min, AC_PID_LEAK_MIN),

43


44
    // 8 was for float AFF

45


46
    // @Param: FLTT

47
    // @DisplayName: PID Target filter frequency in Hz

48
    // @Description: Target filter frequency in Hz

49
    // @Units: Hz

50
    AP_GROUPINFO("FLTT", 9, AC_HELI_PID, _filt_T_hz, AC_PID_TFILT_HZ_DEFAULT),

51


52
    // @Param: FLTE

53
    // @DisplayName: PID Error filter frequency in Hz

54
    // @Description: Error filter frequency in Hz

55
    // @Units: Hz

56
    AP_GROUPINFO("FLTE", 10, AC_HELI_PID, _filt_E_hz, AC_PID_EFILT_HZ_DEFAULT),

57


58
    // @Param: FLTD

59
    // @DisplayName: PID D term filter frequency in Hz

60
    // @Description: Derivative filter frequency in Hz

61
    // @Units: Hz

62
    AP_GROUPINFO("FLTD", 11, AC_HELI_PID, _filt_D_hz, AC_PID_DFILT_HZ_DEFAULT),

63


64
    // @Param: SMAX

65
    // @DisplayName: Slew rate limit

66
    // @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.

67
    // @Range: 0 200

68
    // @Increment: 0.5

69
    // @User: Advanced

70
    AP_GROUPINFO("SMAX", 12, AC_HELI_PID, _slew_rate_max, 0),

71


72
    // @Param: PDMX

73
    // @DisplayName: PD sum maximum

74
    // @Description: The maximum/minimum value that the sum of the P and D term can output

75
    // @User: Advanced

76
    AP_GROUPINFO("PDMX", 13, AC_HELI_PID, _kpdmax, 0),

77


78
    // @Param: D_FF

79
    // @DisplayName: PID Derivative FeedForward Gain

80
    // @Description: FF D Gain which produces an output that is proportional to the rate of change of the target

81
    // @Range: 0 0.02

82
    // @Increment: 0.0001

83
    // @User: Advanced

84
    AP_GROUPINFO("D_FF", 14, AC_HELI_PID, _kdff, 0),

85


86
#if AP_FILTER_ENABLED

87
    // @Param: NTF

88
    // @DisplayName: PID Target notch filter index

89
    // @Description: PID Target notch filter index

90
    // @Range: 1 8

91
    // @User: Advanced

92
    AP_GROUPINFO("NTF", 15, AC_HELI_PID, _notch_T_filter, 0),

93


94
    // @Param: NEF

95
    // @DisplayName: PID Error notch filter index

96
    // @Description: PID Error notch filter index

97
    // @Range: 1 8

98
    // @User: Advanced

99
    AP_GROUPINFO("NEF", 16, AC_HELI_PID, _notch_E_filter, 0),

100
#endif

101


102
    AP_GROUPEND

103
};

104


105
// This is an integrator which tends to decay to zero naturally

106
// if the error is zero.

107


108
void AC_HELI_PID::update_leaky_i(float leak_rate)

109
{

110
    if (!is_zero(_ki)){

111


112
        // integrator does not leak down below Leak Min

113
        if (_integrator > _leak_min){

114
            _integrator -= (float)(_integrator - _leak_min) * leak_rate;

115
        } else if (_integrator < -_leak_min) {

116
            _integrator -= (float)(_integrator + _leak_min) * leak_rate;

117
        }

118


119
    }

120
}

121


122