Operating Unknown Constrained Mechanisms with Compliant Robots

We present an approach for operating unknown one-degree-of-freedom (DoF) mechanisms, using a compliant robot. The key aspect of our approach is that we make only little assumptions about the operated mechanism in terms of imposed kinematic constraints on the end-effector as well as dynamic properties, which can not always be neglected. The proposed system consists of: i) a constraint estimator using end-effector velocity measurements to obtain the first order constraint parameter; ii) a controller, using the estimation to produce adequate set-points for the compliant robot; and iii) a controller for a moving base to extend the workspace of the attached manipulator. The proposed scheme was implemented on two conceptually different robots which demonstrates the general applicability on different hardware. The implementations were successfully tested on various mechanisms in human environment, like doors, drawers or cranks.