PR2 submechanism for one arm only

[dhruvms]

The PR2 URDF that I am using has a 45-dimensional joint configuration vector. For my application, I only care about 7 of those joints in the right arm. The first of those (r_shoulder_pan_joint) joins torso_lift_link and r_shoulder_pan_link, but torso_lift_link has three other child branches that I do not care about. I have tried:

1. Using submechanism
   • Rooting it at torso_lift_link brings the three child branches that I do not care about into the mechanism.
   • Rooting it at r_shoulder_pan_link means I lose r_shoulder_pan_joint in my mechanism.
2. Using remove_joint!
   • For this URDF at least, any call that I have tried to make to remove_joint! gives me a "Graph is not connected." error.

Is there a way to work with a partial chain from a URDF?

[tkoolen]

You should be able to use the remove_subtree! function I just added to do this. Let me know if there's any trouble.