We're using move_arm on our custom Katana-based robot (5 DoF). Sending a goal with pose + orientation constraint works more or less; it usually fails a couple of times (since no IK solution could be found), so we sample around the desired goal pose until we find a solution.

But when I use IK to first calculate a joint state and then send that joint constraint to move_arm, I often get the following error:

Will not plan to requested joint goal since it is in collision

Analysis of the error shows that it's between one link of the arm and a collision object that I've added to the scene. I actually want those objects to collide, and added this to allowed_contacts, so it's strange that move_arm complains.

On further testing, I've noticed that if I use the exact pose that move_arm accepted as a pose goal, and use that as input to the IK, it works.

This all leads me to believe that move_arm does some additional checks on the IK solutions.

Any ideas?