ardupilot/libraries/AP_Proximity/AP_Proximity_Backend.h

103 lines
4.9 KiB
C++

/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <AP_Common/AP_Common.h>
#include <AP_HAL/AP_HAL.h>
#include "AP_Proximity.h"
#define PROXIMITY_SECTORS_MAX 12 // maximum number of sectors
#define PROXIMITY_BOUNDARY_DIST_MIN 0.6f // minimum distance for a boundary point. This ensures the object avoidance code doesn't think we are outside the boundary.
#define PROXIMITY_BOUNDARY_DIST_DEFAULT 100 // if we have no data for a sector, boundary is placed 100m out
class AP_Proximity_Backend
{
public:
// constructor. This incorporates initialisation as well.
AP_Proximity_Backend(AP_Proximity &_frontend, AP_Proximity::Proximity_State &_state);
// we declare a virtual destructor so that Proximity drivers can
// override with a custom destructor if need be
virtual ~AP_Proximity_Backend(void) {}
// update the state structure
virtual void update() = 0;
// get maximum and minimum distances (in meters) of sensor
virtual float distance_max() const = 0;
virtual float distance_min() const = 0;
// handle mavlink DISTANCE_SENSOR messages
virtual void handle_msg(mavlink_message_t *msg) {}
// get distance in meters in a particular direction in degrees (0 is forward, clockwise)
// returns true on successful read and places distance in distance
bool get_horizontal_distance(float angle_deg, float &distance) const;
// get boundary points around vehicle for use by avoidance
// returns nullptr and sets num_points to zero if no boundary can be returned
const Vector2f* get_boundary_points(uint16_t& num_points) const;
// get distance and angle to closest object (used for pre-arm check)
// returns true on success, false if no valid readings
bool get_closest_object(float& angle_deg, float &distance) const;
// get number of objects, angle and distance - used for non-GPS avoidance
uint8_t get_object_count() const;
bool get_object_angle_and_distance(uint8_t object_number, float& angle_deg, float &distance) const;
// get distances in 8 directions. used for sending distances to ground station
bool get_distances(AP_Proximity::Proximity_Distance_Array &prx_dist_array) const;
protected:
// set status and update valid_count
void set_status(AP_Proximity::Proximity_Status status);
// find which sector a given angle falls into
bool convert_angle_to_sector(float angle_degrees, uint8_t &sector) const;
// initialise the boundary and sector_edge_vector array used for object avoidance
// should be called if the sector_middle_deg or _setor_width_deg arrays are changed
void init_boundary();
// update boundary points used for object avoidance based on a single sector's distance changing
// the boundary points lie on the line between sectors meaning two boundary points may be updated based on a single sector's distance changing
// the boundary point is set to the shortest distance found in the two adjacent sectors, this is a conservative boundary around the vehicle
void update_boundary_for_sector(uint8_t sector);
// get ignore area info
uint8_t get_ignore_area_count() const;
bool get_ignore_area(uint8_t index, uint16_t &angle_deg, uint8_t &width_deg) const;
bool get_next_ignore_start_or_end(uint8_t start_or_end, int16_t start_angle, int16_t &ignore_start) const;
AP_Proximity &frontend;
AP_Proximity::Proximity_State &state; // reference to this instances state
// sectors
uint8_t _num_sectors = 8;
uint16_t _sector_middle_deg[PROXIMITY_SECTORS_MAX] = {0, 45, 90, 135, 180, 225, 270, 315, 0, 0, 0, 0}; // middle angle of each sector
uint8_t _sector_width_deg[PROXIMITY_SECTORS_MAX] = {45, 45, 45, 45, 45, 45, 45, 45, 0, 0, 0, 0}; // width (in degrees) of each sector
// sensor data
float _angle[PROXIMITY_SECTORS_MAX]; // angle to closest object within each sector
float _distance[PROXIMITY_SECTORS_MAX]; // distance to closest object within each sector
bool _distance_valid[PROXIMITY_SECTORS_MAX]; // true if a valid distance received for each sector
// fence boundary
Vector2f _sector_edge_vector[PROXIMITY_SECTORS_MAX]; // vector for right-edge of each sector, used to speed up calculation of boundary
Vector2f _boundary_point[PROXIMITY_SECTORS_MAX]; // bounding polygon around the vehicle calculated conservatively for object avoidance
};