Changing link name causes parse error

Question

I'm trying to follow the beginner's tutorial shown here:

http://wiki.ros.org/urdf/Tutorials/Building%20a%20Visual%20Robot%20Model%20with%20URDF%20from%20Scratch

For some reason, if I change the name of a link—e.g., from "right_leg" to "leg"—I get a urdf parse error. The error goes away as soon as I revert the link names to their original values. No idea why this is happening—or why it should ever. It seems that link names should be anything we deem suitable?

I'm running ros with rviz hydro on a VirtualBox virtual machine.

Thanks!

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Originally posted by not_a_robot on ROS Answers with karma: 1 on 2016-09-17

Post score: 0

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Original comments

Comment by JoshMarino on 2016-09-17:
What are you trying to run from the tutorial when this error occurs? Also, what is the error message?

Sounds like something else running is depending on this name, not a URDF error, because link names are allowed to change.

Answer 1

Without seeing the actual error this is a bit of a guess, but:

You can name links any way you want (as long as you take care to follow the ROS naming conventions), but as @JoshMarino writes, you'll have to keep track of where those links are used and update those references as well.

Links in a urdf can be parents and children in joints fi, and the urdf parser will not be able to construct a tree for you if either of those doesn't resolve to a known link.

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Originally posted by gvdhoorn with karma: 86574 on 2016-09-18

This answer was ACCEPTED on the original site

Post score: 0