Design of an under-actuated wrist based on adaptive synergies
This paper describes the design and experimental validation of a three degree-of-freedom (DOF) robotic wrist which enables high-precision, anthropomorphic motion suitable for both teleoperative and automated robotic micromanipulation tasks. The proposed parallel-platform based robotic wrist improves upon previous wrist designs by combining the mechanical stiffness and precision of conventional parallel-platform manipulators (PPMs) with the larger workspaces and more dexterous motion of serial chain manipulators (SCMs). This robotic wrist also includes a non-backdrivable actuation mechanism, a continuous tool rotation DOF which allows for non-anthropomorphic twisting motions necessary for drilling and screw mating, and a coaxial channel through which wires and tubes can pass. A dexterous wrist prototype demonstrates an angular motion resolution of 0.1° and a motion bandwidth of 3.0Hz over a motion range greater than that of the human wrist.