Costmap 2D

Source code on Github.

The Costmap 2D package implements a 2D grid-based costmap for environmental representations and a number of sensor processing plugins. It is used in the planner and controller servers for creating the space to check for collisions or higher cost areas to negotiate around.

Costmap2D ROS Parameters

always_send_full_costmap:
 
Type Default
bool False
Description

Whether to send full costmap every update, rather than updates.
footprint_padding:
 
Type Default
double 0.01
Description

Amount to pad footprint (m).
footprint:
Type Default
vector<double> “[]”
Description

Ordered set of footprint points passed in as a string, must be closed set. For example, the following defines a square base with side lengths of 0.2 meters footprint: “[ [0.1, 0.1], [0.1, -0.1], [-0.1, -0.1], [-0.1, 0.1] ]”.
global_frame:
Type Default
string “map”
Description

Reference frame.
height:
Type Default
int 5
Description

Height of costmap (m).
width:
Type Default
int 5
Description

Width of costmap (m).
lethal_cost_threshold:
 
Type Default
int 100
Description

Minimum cost of an occupancy grid map to be considered a lethal obstacle.
map_topic:
Type Default
string “map”
Description

Topic of map from map_server or SLAM.
observation_sources:
 
Type Default
string “”
Description

List of sources of sensors as a string, to be used if not specified in plugin specific configurations. Ex. “static_layer stvl_layer”
origin_x:
Type Default
double 0.0
Description

X origin of the costmap relative to width (m).
origin_y:
Type Default
double 0.0
Description

Y origin of the costmap relative to height (m).
publish_frequency:
 
Type Default
double 1.0
Description

Frequency to publish costmap to topic.
resolution:
Type Default
double 0.1
Description

Resolution of 1 pixel of the costmap, in meters.
robot_base_frame:
 
Type Default
string “base_link”
Description

Robot base frame.
robot_radius:
Type Default
double 0.1
Description

Robot radius to use, if footprint coordinates not provided.
rolling_window:
Type Default
bool False
Description

Whether costmap should roll with robot base frame.
track_unknown_space:
 
Type Default
bool False
Description

If false, treats unknown space as free space, else as unknown space.
transform_tolerance:
 
Type Default
double 0.3
Description

TF transform tolerance.
trinary_costmap:
 
Type Default
bool True
Description

If occupancy grid map should be interpreted as only 3 values (free, occupied, unknown) or with its stored values.
unknown_cost_value:
 
Type Default
int 255
Description

Cost of unknown space if tracking it.
update_frequency:
 
Type Default
double 5.0
Description

Costmap update frequency.
use_maximum:
Type Default
bool False
Description

whether when combining costmaps to use the maximum cost or override.
clearable_layers:
 
Type Default
vector<string> {“obstacle_layer”, “voxel_layer”, “range_layer”}
Description

Layers that may be cleared using the clearing service.
plugins:
Type Default
vector<string> {“static_layer”, “obstacle_layer”, “inflation_layer”}
Description

List of mapped plugin names for parameter namespaces and names.

Note

Each plugin namespace defined in this list needs to have a plugin parameter defining the type of plugin to be loaded in the namespace.

Example:

local_costmap:
  ros__parameters:
    plugins: ["obstacle_layer", "voxel_layer", "inflation_layer"]
    obstacle_layer:
      plugin: "nav2_costmap_2d::ObstacleLayer"
    voxel_layer:
      plugin: "nav2_costmap_2d::VoxelLayer"
    inflation_layer:
      plugin: "nav2_costmap_2d::InflationLayer"

Default Plugins

When the plugins parameter is not overridden, the following default plugins are loaded:

Namespace Plugin
“static_layer” “nav2_costmap_2d::StaticLayer”
“obstacle_layer” “nav2_costmap_2d::ObstacleLayer”
“inflation_layer” “nav2_costmap_2d::InflationLayer”

Example

global_costmap:
  global_costmap:
    ros__parameters:
      footprint_padding: 0.03
      update_frequency: 1.0
      publish_frequency: 1.0
      global_frame: map
      robot_base_frame: base_link
      use_sim_time: True
      robot_radius: 0.22 # radius set and used, so no footprint points
      resolution: 0.05
      plugins: ["static_layer", "obstacle_layer", "voxel_layer", "inflation_layer"]
      obstacle_layer:
        plugin: "nav2_costmap_2d::ObstacleLayer"
        enabled: True
        observation_sources: scan
        footprint_clearing_enabled: true
        max_obstacle_height: 2.0
        combination_method: 1
        scan:
          topic: /scan
          obstacle_max_range: 2.5
          obstacle_min_range: 0.0
          raytrace_max_range: 3.0
          raytrace_min_range: 0.0
          max_obstacle_height: 2.0
          min_obstacle_height: 0.0
          clearing: True
          marking: True
          data_type: "LaserScan"
          inf_is_valid: false
      voxel_layer:
        plugin: "nav2_costmap_2d::VoxelLayer"
        enabled: True
        footprint_clearing_enabled: true
        max_obstacle_height: 2.0
        publish_voxel_map: True
        origin_z: 0.0
        z_resolution: 0.05
        z_voxels: 16
        max_obstacle_height: 2.0
        unknown_threshold: 15
        mark_threshold: 0
        observation_sources: pointcloud
        combination_method: 1
        pointcloud:  # no frame set, uses frame from message
          topic: /intel_realsense_r200_depth/points
          max_obstacle_height: 2.0
          min_obstacle_height: 0.0
          obstacle_max_range: 2.5
          obstacle_min_range: 0.0
          raytrace_max_range: 3.0
          raytrace_min_range: 0.0
          clearing: True
          marking: True
          data_type: "PointCloud2"
      static_layer:
        plugin: "nav2_costmap_2d::StaticLayer"
        map_subscribe_transient_local: True
        enabled: true
        subscribe_to_updates: true
        transform_tolerance: 0.1
      inflation_layer:
        plugin: "nav2_costmap_2d::InflationLayer"
        enabled: true
        inflation_radius: 0.55
        cost_scaling_factor: 1.0
        inflate_unknown: false
        inflate_around_unknown: true
      always_send_full_costmap: True


local_costmap:
  local_costmap:
    ros__parameters:
      update_frequency: 5.0
      publish_frequency: 2.0
      global_frame: odom
      robot_base_frame: base_link
      use_sim_time: True
      rolling_window: true
      width: 3
      height: 3
      resolution: 0.05