Automatic and hand guided self-registration between a robot and an optical tracking system

In this paper an self-registration method for a robot with an optical tracking system (OTS) is presented. The ability of the used KUKA lightweight robot allows to perform the registration in hand guided mode or completely automatically. The hand guidance allows the user to register the robot with the tracking system in a very fast and intuitive way. He can take the robot by hand and move it and the registration is performed automatically. The mathematical goal is to find a rotation and translation to compute the pose of the robot base and end effector in terms of the coordinate system of the OTS. At each position the pose of the rigid body as well as the TCP of the robot is determined. Since the origin of the rigid body usually is different from the TCP a simple point-to-point transformation as e.g. provided by Horn is not suitable. The problem was reformulated to avoid this and solved with a modified Gauss Newton algorithm.