The Inverse kinematics with constraints awareness allows to specify contacts between any two objects with the OrderedCollisionOperation messages. I tried this on the PR2 with the first object being "right_arm" and the second object one that I added before. However, the IK seems to be politely and silently ignoring this bit of the message. How can I allow contacts with known objects? How can I visualize the added objects in RVIZ to debug? P.S. A similar question is herebut the answer is: use a non-collision aware IK! Lorenzo -- Lorenzo Riano, PhD Research Associate Intelligent Systems Research Centre University of Ulster Magee campus Londonderry BT48 7JL phone: +44 (0)28 71375187 email: l.riano@ulster.ac.uk, lorenzo.riano@gmail.com skype: lorenzo.riano Webpage: http://isrc.ulster.ac.uk/Staff/LRiano/Contact.html