A New Dexterous Hand Based on Bio-Inspired Finger Design for Inside-Hand Manipulation

This paper presents a new design of finger proposed by the ROBIOSS team of the PPRIME Institute: it is a fully actuated bio-inspired four-degree-of-freedom (DOF) finger driven by four actuators. It has been developed with the aim to replicate fine manipulation with fingertips with a high degree of interaction with the environment. This paper proposes to realize a robotic hand for inside-hand fine manipulation and adaptive grasping. The robotic hand is equipped with fingers whose design is based on a human anatomical finger model. Thus, several fingers can be assembled for building a human-sized dexterous hand with an anthropomorphic look. The modular design offers the ability to choose the number of fingers to be used as well as to adjust finger placement based on the manipulation task requirement. The tendon-based actuation presents a routing of the tendons that minimizes friction, kinematic, and static coupling between different finger axes in the transmission from motors to joints. Unlike many existing robotic hands, including our first anthropomorphic hand, we address the difficulties by decoupling joint motions with a new solution for the universal joint at the base of the finger. The results obtained demonstrate an excellent dynamic behavior and accuracy of the finger motion. Finally, the new finger design led to the development of a fully actuated mechanical hand with four fingers and with 16 DOF: the ROBIOSS hand. The hand was embedded on an industrial robot. A manipulation task that uses simultaneously abduction-adduction motion and flexion-extension motion of the finger demonstrates the potential of the hand for accurate manipulation.