mirror of https://github.com/ArduPilot/ardupilot
73 lines
2.4 KiB
C++
73 lines
2.4 KiB
C++
/// @file AC_P_2D.cpp
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/// @brief 2-axis P controller
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#include <AP_Math/AP_Math.h>
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#include "AC_P_2D.h"
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const AP_Param::GroupInfo AC_P_2D::var_info[] = {
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// @Param: P
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// @DisplayName: 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_FLAGS_DEFAULT_POINTER("P", 0, AC_P_2D, _kp, default_kp),
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AP_GROUPEND
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};
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// Constructor
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AC_P_2D::AC_P_2D(float initial_p) :
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default_kp(initial_p)
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{
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// load parameter values from eeprom
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AP_Param::setup_object_defaults(this, var_info);
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}
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// update_all - set target and measured inputs to P controller and calculate outputs
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Vector2f AC_P_2D::update_all(postype_t &target_x, postype_t &target_y, const Vector2f &measurement)
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{
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// calculate distance _error
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_error = (Vector2p{target_x, target_y} - measurement.topostype()).tofloat();
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// Constrain _error and target position
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// Constrain the maximum length of _vel_target to the maximum position correction velocity
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if (is_positive(_error_max) && _error.limit_length(_error_max)) {
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target_x = measurement.x + _error.x;
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target_y = measurement.y + _error.y;
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}
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// MIN(_Dmax, _D2max / _kp) limits the max accel to the point where max jerk is exceeded
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return sqrt_controller(_error, _kp, _D1_max, 0.0);
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}
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// set_limits - sets the maximum error to limit output and first and second derivative of output
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// when using for a position controller, lim_err will be position error, lim_out will be correction velocity, lim_D will be acceleration, lim_D2 will be jerk
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void AC_P_2D::set_limits(float output_max, float D_Out_max, float D2_Out_max)
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{
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_D1_max = 0.0f;
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_error_max = 0.0f;
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if (is_positive(D_Out_max)) {
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_D1_max = D_Out_max;
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}
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if (is_positive(D2_Out_max) && is_positive(_kp)) {
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// limit the first derivative so as not to exceed the second derivative
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_D1_max = MIN(_D1_max, D2_Out_max / _kp);
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}
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if (is_positive(output_max) && is_positive(_kp)) {
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_error_max = inv_sqrt_controller(output_max, _kp, _D1_max);
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}
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}
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// set_error_max - reduce maximum position error to error_max
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// to be called after setting limits
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void AC_P_2D::set_error_max(float error_max)
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{
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if (is_positive(error_max)) {
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if (!is_zero(_error_max) ) {
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_error_max = MIN(_error_max, error_max);
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} else {
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_error_max = error_max;
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}
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}
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}
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