Is a dummy URDF joint for use with kdl kinematic chains recommended for creating a tool point?
(Edited to refer more specifically to URDF with KDL)
I'm using IK from KDL in combination with URDF models recently and noticed that in trying to solve for a tool point I seem to need to have a dummy (fixed) URDF joint at the end of the chain.
The reason this seems to be, unless I misunderstand, is that tips will always be at the origin of some link. Since the point I'm trying to manipulate is at the end of one of my links it seemed the only way to get the IK to solve for that position rather than at the joint & link origin, was to create a dummy fixed joint & link at the location.
This feels a bit wrong, and I'm thinking perhaps it's not the recommended use.
Is there a better way to do this, or is it just the way it's done?
Comments
A few questions: How many degrees of freedom does your chain have without the dummy joint? What is the output you get without the dummy joint, and what's wrong with it?
Wim
(
2011-10-17 11:39:25 -0500
)edit
Edited to try to clarify. I left out DoF as I'm hoping to answer the more conceptual question.
Asomerville
(
2011-10-19 05:39:22 -0500
)editadd a comment
