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How to visualize a frame pose as a path

asked 2012-02-21 03:51:51 -0500

damonkohler gravatar image

updated 2014-01-28 17:11:25 -0500

ngrennan gravatar image

I'd like to generate an image similar to the one at the end of the demo video here: http://www.ros.org/wiki/hector_mapping

In the image, the generated map and the pose of the /base_link frame over time in the /map frame are overlayed. What is the best way to build such an image?

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answered 2012-02-21 04:06:33 -0500

updated 2012-02-22 19:07:37 -0500

The map in the video was generated using the hector_geotiff node. This node retrieves the map and trajectory via services as stated at the wiki page. The trajectory is tracked via the hector_trajector_server package, which provides a node that saves a tf based trajectory given a source and target frame. The trajectory is published on a topic as well as available as a service.

Have you looked at the 'Mapping using logged data' tutorial? The process of mapping and saving to geotiff is described there. Note that the map saving functionality works with maps generated by gmapping or other SLAM systems as well.

/edit: This example launch file should work for you:

<?xml version="1.0"?>

<launch>

  <node pkg="hector_trajectory_server" type="hector_trajectory_server" name="hector_trajectory_server" output="screen">
    <param name="target_frame_name" type="string" value="/map" />
    <param name="source_frame_name" type="string" value="/base_link" />
    <param name="trajectory_update_rate" type="double" value="4" />
    <param name="trajectory_publish_rate" type="double" value="0.25" />
  </node>


  <node pkg="hector_geotiff" type="geotiff_node" name="hector_geotiff_node" output="screen" launch-prefix="nice -n 15">
    <remap from="map" to="/dynamic_map" />
    <param name="map_file_path" type="string" value="$(find hector_geotiff)/maps" />
    <param name="map_file_base_name" type="string" value="hector_slam_map" />
    <param name="draw_background_checkerboard" type="bool" value="true" />
    <param name="draw_free_space_grid" type="bool" value="true" />
  </node>

</launch>

The geotiff map image will be saved every time you publish on the syscommand topic like this:

rostopic pub syscommand std_msgs/String "savegeotiff"
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Comments

Thanks, I did see that but I didn't realize it would work with gmapping (which I'm using currently). I assume the saved map includes the trajectory overlay?

damonkohler gravatar imagedamonkohler ( 2012-02-21 04:27:22 -0500 )edit

Yes it does by default. See edited post above, this launch file should work out of the box if I haven't overlooked anything.

Stefan Kohlbrecher gravatar imageStefan Kohlbrecher ( 2012-02-21 04:53:29 -0500 )edit

Beautiful! Works great, thanks!

damonkohler gravatar imagedamonkohler ( 2012-02-21 19:54:22 -0500 )edit
3

answered 2012-02-21 04:06:59 -0500

DimitriProsser gravatar image

In Rviz, if you enable a nav_msgs/Odometry topic corresponding to /base_link, it will display /base_link's positions over time. You can manually set the number of messages to store in Rviz and then you can see progress over time.

This, of course, assumes that you are correctly publishing an odometry message. This can also be done with a geometry_msgs/PoseStamped that is published based on your robot's position.

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answered 2016-02-22 11:11:15 -0500

130s gravatar image

In jsk_rviz_plugins (that is available via apt for some ROS distros), there is TFTrajectory plugin (, which I assume relies only on tf data over the time, but I haven't looked into detail). image description (img from http://jsk-visualization.readthedocs.... )

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Asked: 2012-02-21 03:51:51 -0500

Seen: 11,075 times

Last updated: Feb 22 '16