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Virtual Joint as part of planning group in moveit!

asked 2013-03-27 06:44:12 -0500

kalectro gravatar image

updated 2013-03-28 20:33:22 -0500

Hi all,

I got my own robot into moveit! and added a planar virtual joint between my robots' base_link and odom like described in the PR2 tutorial. I created a group called 'complete' containing this virtual joint and the arm and would like moveit! to plan the driving path as well as the arm joints. When I start moveit! it outputs this error in the terminal

[ERROR] [1364401925.457291185]: Could not initialize chain object [ERROR] [1364401925.457352872]: Kinematics solver of type 'kdl_kinematics_plugin/KDLKinematicsPlugin' could not be initialized for group 'complete'

When I choose 'complete' as planning group in rviz and set the start state to random and press 'Plan and Execute" it works as desired and I can see it move to the goal state. My problem is that the interactive markers appear at the base_link and not the gripper which I think is due to the error posted above. If I use a planning group without the virtual joint, the markers appear at the correct position but moveit does not plan the driving path for obvious reasons.

Any ideas?

Thanks a lot


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answered 2013-05-15 11:33:39 -0500

Sachin Chitta gravatar image

updated 2017-03-24 17:07:42 -0500

130s gravatar image

Hi Kai,

Could you please ask future MoveIt! related questions on the moveit-users mailing list: . Its easier for us to track MoveIt! specific questions there.

MoveIt! uses KDL for setting up the default kinematics solver. KDL does not support planar joints so that's why you are having trouble setting up a group like this. However, the fact that KDL does not support the planar joint only means that MoveIt! will not do the full inverse kinematics for you directly. You can still send individual joint values as a goal for the motion planning and MoveIt! will plan a path for you.

We will look into adding planar joint support into KDL in the future.

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Asked: 2013-03-27 06:44:12 -0500

Seen: 2,348 times

Last updated: Mar 24 '17