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Could not obtain transform from /gps to base_link

asked 2017-05-16 07:47:32 -0500

DaDaLee gravatar image

After rosrun ekf_localization_node and navsat_transform_node, I got warning like this:

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answered 2017-05-16 18:51:24 -0500

ufr3c_tjc gravatar image

This means you probably haven't defined the gps link in your URDF. The gps link should be a link defined on your robot at the location where your GPS is mounted. Make the joint from the gps link to its parent link a fixed joint, and the transform should then be available to navsat_transform_node.

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Well, it sounds reasonable, but I don't know how and where to define that. Would you mind showing me the detail ? I'm new to navsat_transform_node, thank you so much!

DaDaLee gravatar image DaDaLee  ( 2017-05-17 03:45:33 -0500 )edit

Just add a link in your URDF file called gps. Will give you the details when I can access a PC in an hour or so.

ufr3c_tjc gravatar image ufr3c_tjc  ( 2017-05-17 04:17:03 -0500 )edit

So nice of you. You mean add context like " gps_frame_id : gps " in ekf_template.yaml?

DaDaLee gravatar image DaDaLee  ( 2017-05-17 04:20:46 -0500 )edit

Add this to your URDF file:

<link name="gps"/>

<joint name="gps_to_base_link" type="fixed">
<parent link="base_link"/>
<child link="gps"/>
<origin xyz="0 0 0" rpy="0 0 0"/>
ufr3c_tjc gravatar image ufr3c_tjc  ( 2017-05-17 18:02:56 -0500 )edit

Thank you so much

DaDaLee gravatar image DaDaLee  ( 2017-05-18 01:30:08 -0500 )edit

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Asked: 2017-05-16 07:47:32 -0500

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Last updated: May 16 '17