Coverage Server¶

Source code on Github.

The Coverage Server in opennav_coverage implements the server for handling the complete-coverage planning requests of a given field or zone set in cartesian or GPS coordinates using the Fields2Cover library. It can also compute coverage route and plans using a precomputed set of rows using the opennav_row_coverage server. It is within the opennav_coverage project, not within Nav2 directly, but is planned for a longer-term integration once a few key features are available in Fields2Cover. If you wish to contribute to this effort, please let a maintainer know!

Note: All default_ prefixed parameters can be overwritten in the action request field. When modes are not set in the Action goal, the defaults are utilized.

Parameters¶

action_server_result_timeout

Type	Default
double	10.0

Description: The timeout for rclcpp to keep action results active before caching them as complete. Set as higher than ROS 2 default since this is a longer-running task server.

coordinates_in_cartesian_frame

Type	Default
bool	true

Description: Whether or not requests coming into the server will be in cartesian (e.g. meters) or GPS coordinates. If GPS, they are automatically converted into UTM frame (for meters) to compute the coverage paths, then converted back into GPS for the client.

robot_width

Type	Default
double	2.1

Description: The robot’s width in meters.

operation_width

Type	Default
double	2.5

Description: The robot’s operational width (cleaning, planting, etc) for computing coverage swath distances

min_turning_radius

Type	Default
double	0.4

Description: The robot’s minimum turning radius for computing paths connecting route swaths (m)

linear_curv_change

Type	Default
double	2.0

Description: The robot’s maximum linear curvature change for computing paths connecting route swaths (1/m^2)

default_allow_overlap

Type	Default
bool	false

Description: Whether, by default, to allow overlapping of the last row in the coverage plan to obtain coverage at the far edge. Only for opennav_coverage.

default_headland_type

Type	Default
string	“CONSTANT”

Description: The default headland generation method. Constant is the only valid method currently. Only for opennav_coverage.

default_headland_width

Type	Default
double	2.0

Description: The default headland width to remove from the field or zone from coverage planning. Only for opennav_coverage.

default_swath_type

Type	Default
string	“LENGTH”

Description: Objective to use to score swath generation candidates at different angles when using BRUTE_FORCE swath angle type. Options: LENGTH, COVERAGE, NUMBER for opennav_coverage. Option: OFFSET, CENTER, ROWSARESWATHS for opennav_row_coverage. Note that Coverage takes 10x longer than others.

default_swath_angle_type

Type	Default
double	1.7e-2

Description: Mode to use for generating swaths. Need to find optimal angle by the swath generator objectives, if not given. Options: BRUTE_FORCE, SET_ANGLE. Only for opennav_coverage.

default_step_angle

Type	Default
double	1.7e-2

Description: The angular step size to try to find the optimal angle for route objective, when using BRUTE_FORCE swath angle type. Default is 1 deg in rad units. Only for opennav_coverage.

default_swath_angle

Type	Default
double	N/A

Description: The optimal angle for route objective, when using SET_ANGLE swath angle type. Default is 1 deg in rad units. Only for opennav_coverage.

default_route_type

Type	Default
string	“BOUSTROPHEDON”

Description: Default order when computing routes to order swaths. Options: BOUSTROPHEDON, SNAKE, SPIRAL, CUSTOM

default_custom_order

Type	Default
vector<int>	N/A

Description: The default custom swath order for the route planner in the CUSTOM mode. The length of this custom order must be >= swaths.size(). Only relevent when using the CUSTOM Route Type.

default_spiral_n

Type	Default
int	4

Description: Default number of swaths to skip and double back on to create a spiral pattern in the route. Only relevent when usign the SPIRAL Route Type. SNAKE is a special case when Spiral N = 2.

default_path_continuity_type

Type	Default
string	“CONTINUOUS”

Description: Default continuity type when computing paths to connect routes together. Options DISCONTINUOUS, CONTINUOUS.

default_path_type

Type	Default
string	“DUBIN”

Description: Default type when computing paths to connect routes together using curves. Options: DUBIN, REEDS_SHEPP.

default_turn_point_distance

Type	Default
double	0.1

Description: Distance between points on the plan and route for sending back in paths (e.g. 0.1m). This impacts the density of the output turn paths and the overall nav paths.

default_offset

Type	Default
double	0.0

Description: Offset to use for computing swaths from annotated rows. Only for opennav_row_coverage.

order_ids

Type	Default
bool	0.0

Description: For opennav_row_coverage, whether to reorder the parsed rows in the order of their ``id``s.

Example¶

coverage_server:
  ros__parameters:
    action_server_result_timeout: 10.0
    coordinates_in_cartesian_frame: true
    robot_width: 2.1
    operation_width: 2.5
    min_turning_radius: 0.4
    linear_curv_change: 2.0
    default_allow_overlap: true
    default_headland_width: 0.5
    default_path_continuity_type: "CONTINUOUS"
    default_path_type: "DUBINS"
    default_route_type: "BOUSTROPHEDON"
    default_swath_angle_type: "BRUTE_FORCE"
    default_swath_type: "LENGTH"
    default_turn_point_distance: 0.1