coverage_path

This package generates an optimal path to cover a given area with a cyber physical system (CPS).

Dependencies

This package depends on the following message definitions:

• geometry_msgs
• nav_msgs
• cpswarm_msgs

The communication between CPSs is based on the CPSwarm Communication Library.

The following packages of the swarm functions library are required:

• area_division (only if divide_area=true)
• state_exchanger

The following packages of the sensing and actuation library are required:

• area_provider (only if divide_area=false)

Further required packages are:

• roscpp
• tf2

Execution

Run the launch file

roslaunch coverage_path coverage_path.launch

to launch the coverage_path node.

The launch file can be configured with following parameters:

• id (integer, default: 1) The identifier (ID) of the CPS used for name spacing in simulation.
• output (string, default: screen) Whether to show the program output (screen) or to write it to a log file (log).

In the param subdirectory there is the parameter file coverage_path.yaml that allows to configure the behavior of the coverage_path node.

Nodes

coverage_path

The coverage_path node generates a path that allows a CPS to cover a given area. It uses the area assigned by the area_division package. The generated coverage path is based on a minimum spanning tree to optimally sweep the area. The path is regenerated when area to be covered changes. The path can be retrieved either as a whole or waypoint after waypoint. In the latter case, the current waypoint is returned, based on the current position of the CPS.

Subscribed Topics

• area/assigned (nav_msgs/OccupancyGrid) The area to be covered by this CPS. Only called if divide_area=true.
• area/map (nav_msgs/OccupancyGrid) The area to be covered. Only called if divide_area=false.

Published Topics

• coverage_path/path (nav_msgs/Path) The generated path for visualization purposes. Only published if the parameter visualize is set to true.
• coverage_path/waypoint (geometry_msgs/PointStamped) The current waypoint of the generated path for visualization purposes. Only published if the parameter visualize is set to true.
• coverage_path/mst (geometry_msgs/PoseArray) The minimum spanning tree of the area for visualization purposes. Only published if the parameter visualize is set to true.

Services

• coverage_path/path (nav_msgs/GetPlan) Provides the complete generated path.
• coverage_path/waypoint (cpswarm_msgs/GetWaypoint) Provides the current waypoint of the generated path.

Services Called

• area/get_area (cpswarm_msgs/GetPoints) Get the points defining the polygon of the area to be covered.

Parameters

• ~loop_rate (real, default: 1.5) The frequency in Hz at which to run the control loops.
• ~queue_size (integer, default: 1) The size of the message queue used for publishing and subscribing to topics.
• ~resolution (real, default: 1.0) The grid map underlying the path planning will be downsampled to this resolution in meter / cell.
• ~visualize (boolean, default: false) Whether to publish the coverage path on a topic for visualization.
• ~divide_area (boolean, default: false) Whether to divide the area among the CPSs before generating the path or to generate the path on the complete map. If true, downsampling is not available.
• ~vertical (boolean, default: false) Whether the sweeping pattern is vertical or horizontal.
• ~turning_points (boolean, default: false) Whether there are only waypoints at turning points of the path or also waypoints regularly spaced on straight line segments of the path.

Code API

coverage_path package code API documentation

Changelog for package coverage_path

1.1.0 (2019-10-31)

• Initial release of coverage_path
• Contributors: Micha Sende