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Rviz cannot find transform

asked 2020-05-28 07:55:30 -0600

czr gravatar image


I am trying to visualize a point cloud generated by rtabmap on Rviz, but I am getting the following error:

Transform [sender=unknown_publisher]
For frame [map]: No transform to fixed frame [base_footprint]. TF error: [Could not find a connection between 'base_footprint' and 'map' because they are not part of the same tree.Tf has two or more unconnected trees.]

But I visualized my rqt_tf_tree and everything seems connected, as you can see on the image.

image description

Also, when running rtabmap though the stereo launch file, I can see the point clouds generated by the stereo images.

So, what might be wrong?

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answered 2020-05-28 08:49:22 -0600

Dragonslayer gravatar image

The Error is about base_footprint, but the tf tree shows map -> base_link. I dont see how base_footprint has any relevance here. Either link ekf to base_footprint instead of base_link and footprint to base_link (static transform publisher maybe). Or get rid of base_footprint, depending on robot base.

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Maybe somewhere in the config files there is a reference to base_footprint. If you are not yet mapping or navigating, I would check the rtabmap launchfiles and parameters. Would be helpful if you could post a "rosparam dump" should be the quickest way to find out if its set as a frame_id somewhere.

Dragonslayer gravatar image Dragonslayer  ( 2020-05-28 08:54:52 -0600 )edit

Thanks for your response, rosparam dump only mentions base_footprinton husky definition. Here the output:

czr gravatar image czr  ( 2020-05-28 17:06:13 -0600 )edit

I would suggest making base_footprint the reference:

ekf_localization: base_link_frame: base_link --------> base_link_frame: base_footprint

or get rid of base_footprint in the husky urdf, dont forget the joints though. However Iam not really sure why the build tf tree, that seems to be fine, would block your pointcloud from being displayed.

Dragonslayer gravatar image Dragonslayer  ( 2020-05-28 19:21:37 -0600 )edit

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Asked: 2020-05-28 07:55:30 -0600

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Last updated: May 28 '20