Design of a Compliant and Force Sensing Hand for a Humanoid Robot

Abstract : Robot manipulation tasks in unknown and unstructured environments can often be better addressed with hands that are capable of force-sensing and passive compliance. We describe the design of a compact four degree-of-freedom (DOF) hand that exhibits these properties. This hand is being developed for a new humanoid robot platform. Our hand contains four modular Force Sensing Compliant (FSC) actuators acting on three fingers. One actuator controls the spread between two fingers. Three actuators independently control the top knuckle of each finger. The lower knuckles of the finger are passively coupled to the top knuckle. We place a pair of torsion springs between the motor housing and the hand chassis. By measuring the deflection of these springs, we can determine the acting force of the actuator. The springs also provide compliance in the finger and protect the motor gearbox from high impact shocks. Our novel actuators, combined with embedded control electrics, allow for a compact and dexterous hand design that is well suited to humanoid manipulation research.