End-effector position from tf is not same as the iterative marker in Rviz [closed]

asked 2021-05-21 16:17:12 -0500

hzhao9 gravatar image

Dear community,

I have built a custom urdf file with the ur5 official urdf file and our custom end-effector, the end effector is connected to the link "tool0". The moveit-config package is generate using moveit assistant with the custom urdf file. after play with it for a while I found that the end-effector position gets by the moveit group "getCurrentPose()" is not the same as the position of the iterative marker in Rviz. The further the end-effector is moving away from the initial position, the bigger the error is. I don't understand why this can happened, everything looks normal to after viewing the frames tree generated by the tf "view_frames".

Also, when I use tf_echo to check the transformation between /base_link and /SCOPE(our end-effector), it shows "Exception thrown: Could not find a connection between 'world' and 'SCOPE' because they are not part of the same tree.Tf has two or more unconnected trees." After a while, it gives me some position and orientation results. it seems weird to me.

If you can help it will be greatly appreciated, and if you need any further details or infos, please let me know.

Thanks in advanced.

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Closed for the following reason Gazebo Question: The Gazebo community prefers to answer questions at: http://answers.gazebosim.org by hzhao9
close date 2021-06-03 15:55:58.627629


For others to be able to help you: is this a real UR5? Are you using simulation? If so: which simulator? Which driver(s)? etc, etc.

gvdhoorn gravatar image gvdhoorn  ( 2021-05-22 02:43:55 -0500 )edit

@gvdhoorn Thanks so much for your reply. Currently, we are using simulation in Gazebo with ROS melodic in Ubuntu 18.04. The Robot is with the end-effector is set up with the moveit-assistant, and the arm controller is the joint-state-controller and position controller. Please let me know if there is any info is missing. Thanks!

hzhao9 gravatar image hzhao9  ( 2021-05-24 15:13:59 -0500 )edit