Investigation and Design of Robotic Assistance Control System for Cooperative Manipulation

Cooperative manipulation has become an important task in both industrial and domestic settings. Control of dexterous robotic systems to assist such task is challenging. In this paper, we first investigate three impedance-based control approaches for robotic assistance in cooperative manipulation. In particular, we study the level of assistance and cooperation from each approach by performing physical human-robot interaction (pHRI) experiments. Modern robotic manipulators are equipped with sophisticated robot hands to perform dexterous manipulation. The multi-fingered hand-arm cooperation with a human partner can be improved by adding admittance or impedance control to the finger part sensing interaction forces. The conventional way of using force/torque sensors at the wrist has limitations in distinguishing internal and external forces as well as relating the point of interaction. Tactile sensing can be useful in such a system to estimate the forces exerted by the human user during the interaction as well as to distinguish the applied contact force. Second, detection of human intended forces is demonstrated with a tactile based multi-fingered robot hand. Finally, a novel design of an assistance system that incorporates tactile sensing and chosen assistance approach modeled as a virtual tool in admittance control is presented for dexterous robot-human cooperative object manipulation.