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moveit joint with more than 2pi rotation

asked 2017-08-09 05:02:32 -0500

lbalog gravatar image

hey, i was wondering if im doing something wrong or if moveit cant handle revolute joints which surpass -2pi/2pi. im extending an ur5 with a contiunous joint and moveit automatically limits it to -pi/pi. However if i declare the joint as revolute with some generous limits like -10pi/10pi the planning fails or gives terrible results. Is there any way to fix this problem? thanks

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answered 2017-08-10 04:11:10 -0500

v4hn gravatar image

It can handle continuous or less-limited revolute joints but.

Continuous joints are handled differently from limited joints. Solutions are always given in [-pi;pi] but can wrap around when needed. For execution the generated trajectories can actually unwind and give waypoints outside [-pi;pi].

If you encounter a specific problem here please report it in the github repository.

Simulating continuous joints by larger rotation limits is a bad idea. The biggest problem is that you increase the search space tremendously which is probably why planning times out.

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Do you know if the 'unwind' feature is implemented in the compute_cartesian_path method? Moveit seems to be ignoring waypoints following a -pi to pi (or vice versa) wrap-around in any of the robot joints.

jsather gravatar image jsather  ( 2018-04-12 21:48:23 -0500 )edit

Hello, i have a simular problem. I am working with a KUKA robot which has joint limits of +/-190 degrees. If the robot moves to a position where the limits overlap, it gets trapped there.

Is there a posibility to use revolute joints with limits over +/-pi? Thanks

LorenzS gravatar image LorenzS  ( 2019-04-10 03:20:29 -0500 )edit

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Asked: 2017-08-09 05:02:32 -0500

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Last updated: Aug 10 '17