ardupilot/libraries/AC_Avoidance/AP_OADijkstra.h

190 lines
9.1 KiB
C++

#pragma once
#include <AP_Common/AP_Common.h>
#include <AP_Common/Location.h>
#include <AP_Math/AP_Math.h>
#include <AP_HAL/AP_HAL.h>
#include "AP_OAVisGraph.h"
/*
* Dijkstra's algorithm for path planning around polygon fence
*/
class AP_OADijkstra {
public:
AP_OADijkstra();
/* Do not allow copies */
AP_OADijkstra(const AP_OADijkstra &other) = delete;
AP_OADijkstra &operator=(const AP_OADijkstra&) = delete;
// set fence margin (in meters) used when creating "safe positions" within the polygon fence
void set_fence_margin(float margin) { _polyfence_margin = MAX(margin, 0.0f); }
// update return status enum
enum AP_OADijkstra_State : uint8_t {
DIJKSTRA_STATE_NOT_REQUIRED = 0,
DIJKSTRA_STATE_ERROR,
DIJKSTRA_STATE_SUCCESS
};
// calculate a destination to avoid the polygon fence
// returns DIJKSTRA_STATE_SUCCESS and populates origin_new and destination_new if avoidance is required
AP_OADijkstra_State update(const Location &current_loc, const Location &destination, Location& origin_new, Location& destination_new);
private:
// returns true if at least one inclusion or exclusion zone is enabled
bool some_fences_enabled() const;
enum class AP_OADijkstra_Error : uint8_t {
DIJKSTRA_ERROR_NONE = 0,
DIJKSTRA_ERROR_OUT_OF_MEMORY,
DIJKSTRA_ERROR_OVERLAPPING_POLYGON_POINTS,
DIJKSTRA_ERROR_FAILED_TO_BUILD_INNER_POLYGON,
DIJKSTRA_ERROR_OVERLAPPING_POLYGON_LINES,
DIJKSTRA_ERROR_FENCE_DISABLED,
DIJKSTRA_ERROR_TOO_MANY_FENCE_POINTS,
DIJKSTRA_ERROR_NO_POSITION_ESTIMATE,
DIJKSTRA_ERROR_COULD_NOT_FIND_PATH
};
// return error message for a given error id
const char* get_error_msg(AP_OADijkstra_Error error_id) const;
// report error to ground station
void report_error(AP_OADijkstra_Error error_id);
//
// inclusion polygon methods
//
// check if inclusion polygons have been updated since create_inclusion_polygon_with_margin was run
// returns true if changed
bool check_inclusion_polygon_updated() const;
// create polygons inside the existing inclusion polygons
// returns true on success. returns false on failure and err_id is updated
bool create_inclusion_polygon_with_margin(float margin_cm, AP_OADijkstra_Error &err_id);
//
// exclusion polygon methods
//
// check if exclusion polygons have been updated since create_exclusion_polygon_with_margin was run
// returns true if changed
bool check_exclusion_polygon_updated() const;
// create polygons around existing exclusion polygons
// returns true on success. returns false on failure and err_id is updated
bool create_exclusion_polygon_with_margin(float margin_cm, AP_OADijkstra_Error &err_id);
//
// exclusion circle methods
//
// check if exclusion circles have been updated since create_exclusion_circle_with_margin was run
// returns true if changed
bool check_exclusion_circle_updated() const;
// create polygons around existing exclusion circles
// returns true on success. returns false on failure and err_id is updated
bool create_exclusion_circle_with_margin(float margin_cm, AP_OADijkstra_Error &err_id);
//
// other methods
//
// returns total number of points across all fence types
uint16_t total_numpoints() const;
// get a single point across the total list of points from all fence types
// also returns the type of point
bool get_point(uint16_t index, Vector2f& point) const;
// returns true if line segment intersects polygon or circular fence
bool intersects_fence(const Vector2f &seg_start, const Vector2f &seg_end) const;
// create visibility graph for all fence (with margin) points
// returns true on success. returns false on failure and err_id is updated
bool create_fence_visgraph(AP_OADijkstra_Error &err_id);
// calculate shortest path from origin to destination
// returns true on success. returns false on failure and err_id is updated
// requires create_polygon_fence_with_margin and create_polygon_fence_visgraph to have been run
// resulting path is stored in _shortest_path array as vector offsets from EKF origin
bool calc_shortest_path(const Location &origin, const Location &destination, AP_OADijkstra_Error &err_id);
// shortest path state variables
bool _inclusion_polygon_with_margin_ok;
bool _exclusion_polygon_with_margin_ok;
bool _exclusion_circle_with_margin_ok;
bool _polyfence_visgraph_ok;
bool _shortest_path_ok;
Location _destination_prev; // destination of previous iterations (used to determine if path should be re-calculated)
uint8_t _path_idx_returned; // index into _path array which gives location vehicle should be currently moving towards
// inclusion polygon (with margin) related variables
float _polyfence_margin = 10; // margin around polygon defaults to 10m but is overriden with set_fence_margin
AP_ExpandingArray<Vector2f> _inclusion_polygon_pts; // array of nodes corresponding to inclusion polygon points plus a margin
uint8_t _inclusion_polygon_numpoints; // number of points held in above array
uint32_t _inclusion_polygon_update_ms; // system time of boundary update from AC_Fence (used to detect changes to polygon fence)
// exclusion polygon related variables
AP_ExpandingArray<Vector2f> _exclusion_polygon_pts; // array of nodes corresponding to exclusion polygon points plus a margin
uint8_t _exclusion_polygon_numpoints; // number of points held in above array
uint32_t _exclusion_polygon_update_ms; // system time exclusion polygon was updated (used to detect changes)
// exclusion circle related variables
AP_ExpandingArray<Vector2f> _exclusion_circle_pts; // array of nodes surrounding exclusion circles plus a margin
uint8_t _exclusion_circle_numpoints; // number of points held in above array
uint32_t _exclusion_circle_update_ms; // system time exclusion circles were updated (used to detect changes)
// visibility graphs
AP_OAVisGraph _fence_visgraph; // holds distances between all inclusion/exclusion fence points (with margin)
AP_OAVisGraph _source_visgraph; // holds distances from source point to all other nodes
AP_OAVisGraph _destination_visgraph; // holds distances from the destination to all other nodes
// updates visibility graph for a given position which is an offset (in cm) from the ekf origin
// to add an additional position (i.e. the destination) set add_extra_position = true and provide the position in the extra_position argument
// requires create_polygon_fence_with_margin to have been run
// returns true on success
bool update_visgraph(AP_OAVisGraph& visgraph, const AP_OAVisGraph::OAItemID& oaid, const Vector2f &position, bool add_extra_position = false, Vector2f extra_position = Vector2f(0,0));
typedef uint8_t node_index; // indices into short path data
struct ShortPathNode {
AP_OAVisGraph::OAItemID id; // unique id for node (combination of type and id number)
bool visited; // true if all this node's neighbour's distances have been updated
node_index distance_from_idx; // index into _short_path_data from where distance was updated (or 255 if not set)
float distance_cm; // distance from source (number is tentative until this node is the current node and/or visited = true)
};
AP_ExpandingArray<ShortPathNode> _short_path_data;
node_index _short_path_data_numpoints; // number of elements in _short_path_data array
// update total distance for all nodes visible from current node
// curr_node_idx is an index into the _short_path_data array
void update_visible_node_distances(node_index curr_node_idx);
// find a node's index into _short_path_data array from it's id (i.e. id type and id number)
// returns true if successful and node_idx is updated
bool find_node_from_id(const AP_OAVisGraph::OAItemID &id, node_index &node_idx) const;
// find index of node with lowest tentative distance (ignore visited nodes)
// returns true if successful and node_idx argument is updated
bool find_closest_node_idx(node_index &node_idx) const;
// final path variables and functions
AP_ExpandingArray<AP_OAVisGraph::OAItemID> _path; // ids of points on return path in reverse order (i.e. destination is first element)
uint8_t _path_numpoints; // number of points on return path
Vector2f _path_source; // source point used in shortest path calculations (offset in cm from EKF origin)
Vector2f _path_destination; // destination position used in shortest path calculations (offset in cm from EKF origin)
// return point from final path as an offset (in cm) from the ekf origin
bool get_shortest_path_point(uint8_t point_num, Vector2f& pos);
AP_OADijkstra_Error _error_last_id; // last error id sent to GCS
uint32_t _error_last_report_ms; // last time an error message was sent to GCS
};