all_seaing_navigation

Nodes

navigation_server.py

Handles requests to generate paths from one start point to one end point while avoiding obstacles. Current implementation uses a basic A* search algorithm.

Subscribed topics:

• /dynamic_map: an nav_msgs/msg/OccupancyGrid message containing the map that the search algorithm is being run on.

Action servers:

• follow_path: an all_seaing_interfaces/FollowPath action server for finding the shortest path from the current ship position to requested end point.

grid_map_generator.py

Generates a (large) occupancy grid of all the obstacles encountered. -1 represents unknown cells, 0-100 represents the probability that the cell is occupied by an obstacle.

Subscribed topics:

• obstacle_map/raw: an all_seaing_interfaces/ObstacleMap message containing coordinates of unlabeled obstacles.
• odometry/filtered: an nav_msgs/msg/Odometry message containing the position of the vehicle
• scan: a sensor_msgs/msg/LaserScan message containing the maximum lidar detection range.

Published topics:

• /dynamic_map: an nav_msgs/msg/OccupancyGrid message containing the map that the search algorithm is being run on.

Parameters:

• global_frame_id: a string parameter, defaults to "map". The name of the frame the occupancy grid is under.
• timer_period: a double parameter, defaults to 1.0. ???
• default_lidar_range: a double parameter, defaults to 130.0. The maximum range of the lidar.
• grid_dim: an integer array parameter, defaults to [2000, 2000]. The dimensions of the occupancy grid.
• grid_resolution: a double parameter, defaults to 0.3. ???