Keepout Filter Parameters

Keepout Filter - is a Costmap Filter that enforces robot to avoid keepout areas or stay on preferred lanes, by updating corresponding costmap layer using filter mask information.

Note: As Costmap Filters does not have the inflation layer applied to them (since inflation is not sensible for a speed or other non-occupation zone type), it may be beneficial to add a separate inflation layer into the vector of filters when using only a keepout zone. Some planners (e.g. Smac Feasible) will use the cost of the center point for a collision checking optimization before doing full SE2 footprint checks. Without inflation, the planner will not respect the Keepout Zone on it extremities – but will still respect it for the robot centers. If you wish to have a Keepout Zone for any part of the robot base while using a feasible planner, please enable the inflation layer.

<filter name>: is the corresponding plugin name selected for this type.

<filter name>.enabled

Type	Default
bool	True

Description

Whether it is enabled.

<filter name>.filter_info_topic

Type	Default
string	N/A

Description

Name of the incoming CostmapFilterInfo topic having filter-related information. Published by Costmap Filter Info Server along with filter mask topic. For more details about Map and Costmap Filter Info servers configuration please refer to the Map Server / Saver configuration page.

<filter name>.override_lethal_cost

Type	Default
bool	False

Description

When true, check if the robot is in a lethal keepout zone, if so, replaces those lethal costs with lethal_override_cost.

<filter name>.lethal_override_cost

Type	Default
double	252

Description

The cost value written into those cells instead of lethal cost when override is active. Default sets cost very high to incentivize leaving the area as soon as possible.

<filter name>.transform_tolerance

Type	Default
double	0.1

Description

Time with which to post-date the transform that is published, to indicate that this transform is valid into the future. Used when filter mask and current costmap layer are in different frames.

Example

global_costmap:
  global_costmap:
    ros__parameters:
      ...
      plugins: ["static_layer", "obstacle_layer", "inflation_layer"]
      filters: ["keepout_filter"]
      ...
      keepout_filter:
        plugin: "nav2_costmap_2d::KeepoutFilter"
        enabled: True
        filter_info_topic: "/costmap_filter_info"
        transform_tolerance: 0.1
        override_lethal_cost: True
        lethal_override_cost: 200
...
local_costmap:
  local_costmap:
    ros__parameters:
      ...
      plugins: ["voxel_layer", "inflation_layer"]
      filters: ["keepout_filter"]
      ...
      keepout_filter:
        plugin: "nav2_costmap_2d::KeepoutFilter"
        enabled: True
        filter_info_topic: "/costmap_filter_info"
        transform_tolerance: 0.1
        override_lethal_cost: True
        lethal_override_cost: 200