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Z-coordinate has to be 1 or -1

asked 2015-04-07 14:08:06 -0500

nouf gravatar image

updated 2015-04-08 03:27:02 -0500


I'm starting to build a map using gmapping, but whenever I start slam_gmapping, the following warning is shown:

Laser has to be mounted planar! Z-coordinate has to be 1 or -1, but gave: 0.00000

This is one of the published transformations:

<node pkg="tf" type="static_transform_publisher" name="link2_broadcaster" args="0 0 0.1 0 0 0 1 base_link camera_link 100" />

When I change the X argument into 1 or -1 the warning is gone! I don't know why!.But I'm sure there is something wrong!! and I need the X to be 0.

any idea?


These are the frames in rviz:


and I cannot change the values of the orientation in rviz.

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answered 2015-04-07 18:49:57 -0500

updated 2015-04-07 18:50:12 -0500

That error message is a bit confusing. It is just saying that the plane of the laser needs to be parallel to the ground plane. I would check the transform chain you are using (i.e., what is the orientation of base_link) and make sure it has z facing directly up or down. You can do this in rviz using the tf plugin.

if you're curious, the code producing the error message can be found here

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@Morgan Please see the update in the question

nouf gravatar image nouf  ( 2015-04-08 03:27:49 -0500 )edit

I have bumped into the same problem, have you fixed it, can you share how?

Kishore Kumar gravatar image Kishore Kumar  ( 2016-01-21 10:00:56 -0500 )edit

answered 2016-10-12 18:28:31 -0500

sradmard gravatar image

I was able to fix the problem by making sure that the frame attached to the base_link has its z-axis pointing upward. You can check it through rviz by visualizing tf and selecting individual frames to visualize.

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Asked: 2015-04-07 14:08:06 -0500

Seen: 996 times

Last updated: Oct 12 '16