Visually and force controlled opening and closing of doors by means of a mobile robot arm

A multi-sensory discrete-continuous control concept has been developed to realize interactive basic skills for humanoid and mobile service robots. In the upper hierarchy level a discrete task control structure enables the flexible execution of primitive skill sequences. In the lower continuous level a suitable controller is chosen with control parameters adapted to the current primitive skill. The basic skill for the frequently occurring task of unlocking and opening a door by means of a mobile robot arm has been implemented based on this hierarchical two-level control concept. The perception of the robot environment, the detection of door, handle and keyhole is mainly achieved by vision and force sensor data. A hybrid strategy based on variable impedance control is used for the continuous controller in the lower hierarchy level