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Getting costmap_2d to update with LaserScan data

asked 2014-07-08 18:37:32 -0500

lucasw gravatar image

updated 2020-11-21 11:40:24 -0500

I'd like to run costmap_2d and update a loaded static map with new sensor data, but I don't see any updates happening. I can see the latest LaserScan data in rviz on the /base_scan topic, but shouldn't the map be updated underneath it to show those squares as blocked?

image description

This is my example_params.yaml which I pieced together from and other sources:

global_frame: /map
robot_base_frame: base_link
footprint: [
    # tail
    [-0.325, -0.20],
    [-0.325, 0.2],
    # nose
    [0.325, 0.2],
    [0.34, 0.0],
    [0.325, -0.2]

    - {name: static_map,       type: "costmap_2d::StaticLayer"}
    - {name: inflation,        type: "costmap_2d::InflationLayer"}
    - {name: obstacles,       type: "costmap_2d::ObstacleLayer"}
publish_frequency: 1.0
update_frequency: 4.0
  track_unkown_space: true,
  observation_sources: base_scan
  base_scan: {
    data_type: LaserScan,
    sensor_frame: base_link,
    clearing: true,
    marking: true,
    topic: /base_scan,
    observation_persistance: 15.0

I launch this like this:

<?xml version="1.0"?>

  <node name="costmap_node" pkg="costmap_2d" type="costmap_2d_node" output="screen" >
    <rosparam file="$(find path_planning)/config/example_params.yaml" command="load" ns="costmap" />
  <node name="cm_map_server" pkg="map_server" type="map_server" output="screen" args="$(find path_planning)/config/map.yaml" />

  <node name="cm_rviz1" pkg="rviz" type="rviz" args="-d $(find path_planning)/config/costmap.rviz" />

  <node name="cm_robot_static_tf" pkg="tf" type="static_transform_publisher"  args="0 0 0 0 0 0 map base_link  100" /> 

I then attempt to update the costmap with LaserScan data:

rostopic pub /base_scan sensor_msgs/LaserScan '{header:stamp: now, frame_id: base_link}, angle_min: 0.0, angle_max: 0.1, angle_increment: 0.1, time_increment: 0, scan_time: 0.0, range_min: 0.1, range_max: 3.0, ranges: [2.0, 1.4] }'

It looks like the base_scan is successfully connected to the costmap_node

image description

And this is my map.yaml

image: map.pgm
resolution: 0.025
origin: [-6.000000, -6.000000, 0.0]
negate: 0
occupied_thresh: 0.65
free_thresh: 0.196

image description

Am I wrong to expect that the /costmap_node/costmap/costmap is going to update in response to sensor data marking and clearing it, or is that the responsibility of something else?

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answered 2014-07-08 18:46:17 -0500

lucasw gravatar image

updated 2014-07-08 19:36:19 -0500

It looks like I needed to have negate set to 1 (though FREE_SPACE = 0 in the costmap_2d header file), and then the space near the robot and origin becomes free space and it looks like my LaserScan does mark the obstacles. But why wasn't the raytrace through the LETHAL_OBSTACLE section that the robot was surrounded by getting cleared when negate was 0- because no obstacles from the static map are ever cleared?

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Lucas is correct. Your static map is being loaded backwards.

David Lu gravatar image David Lu  ( 2014-07-09 10:54:01 -0500 )edit

[2.0, 1.4] @lucasw why are you giving only two values for the ranges array in the laser scan msg

pravi gravatar image pravi  ( 2020-11-05 15:29:32 -0500 )edit

@pravi To make the example simple.

lucasw gravatar image lucasw  ( 2020-11-20 15:37:41 -0500 )edit

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Asked: 2014-07-08 18:37:32 -0500

Seen: 910 times

Last updated: Jul 08 '14