ardupilot/libraries/AP_L1_Control/AP_L1_Control.h

113 lines
3.3 KiB
C++

// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
#pragma once
/// @file AP_L1_Control.h
/// @brief L1 Control algorithm. This is a instance of an
/// AP_Navigation class
/*
* Originally written by Brandon Jones 2013
*
* Modified by Paul Riseborough 2013 to provide:
* - Explicit control over frequency and damping
* - Explicit control over track capture angle
* - Ability to use loiter radius smaller than L1 length
*/
#include <AP_Math/AP_Math.h>
#include <AP_AHRS/AP_AHRS.h>
#include <AP_Param/AP_Param.h>
#include <AP_Navigation/AP_Navigation.h>
class AP_L1_Control : public AP_Navigation {
public:
AP_L1_Control(AP_AHRS &ahrs) :
_ahrs(ahrs)
{
AP_Param::setup_object_defaults(this, var_info);
}
/* see AP_Navigation.h for the definitions and units of these
* functions */
int32_t nav_roll_cd(void) const;
float lateral_acceleration(void) const;
// return the desired track heading angle(centi-degrees)
int32_t nav_bearing_cd(void) const;
// return the heading error angle (centi-degrees) +ve to left of track
int32_t bearing_error_cd(void) const;
float crosstrack_error(void) const { return _crosstrack_error; }
float crosstrack_error_integrator(void) const { return _L1_xtrack_i; }
int32_t target_bearing_cd(void) const;
float turn_distance(float wp_radius) const;
float turn_distance(float wp_radius, float turn_angle) const;
void update_waypoint(const struct Location &prev_WP, const struct Location &next_WP);
void update_loiter(const struct Location &center_WP, float radius, int8_t loiter_direction);
void update_heading_hold(int32_t navigation_heading_cd);
void update_level_flight(void);
bool reached_loiter_target(void);
// set the default NAVL1_PERIOD
void set_default_period(float period) {
_L1_period.set_default(period);
}
void set_data_is_stale(void) {
_data_is_stale = true;
}
bool data_is_stale(void) const {
return _data_is_stale;
}
// this supports the NAVl1_* user settable parameters
static const struct AP_Param::GroupInfo var_info[];
private:
// reference to the AHRS object
AP_AHRS &_ahrs;
// lateral acceration in m/s required to fly to the
// L1 reference point (+ve to right)
float _latAccDem;
// L1 tracking distance in meters which is dynamically updated
float _L1_dist;
// Status which is true when the vehicle has started circling the WP
bool _WPcircle;
// bearing angle (radians) to L1 point
float _nav_bearing;
// bearing error angle (radians) +ve to left of track
float _bearing_error;
// crosstrack error in meters
float _crosstrack_error;
// target bearing in centi-degrees from last update
int32_t _target_bearing_cd;
// L1 tracking loop period (sec)
AP_Float _L1_period;
// L1 tracking loop damping ratio
AP_Float _L1_damping;
// previous value of cross-track velocity
float _last_Nu;
// prevent indecision in waypoint tracking
void _prevent_indecision(float &Nu);
// integral feedback to correct crosstrack error. Used to ensure xtrack converges to zero.
// For tuning purposes it's helpful to clear the integrator when it changes so a _prev is used
float _L1_xtrack_i = 0;
AP_Float _L1_xtrack_i_gain;
float _L1_xtrack_i_gain_prev = 0;
uint32_t _last_update_waypoint_us;
bool _data_is_stale = true;
};