Design and Kinematic Analysis of a Novel Series-Parallel Hybrid Finger for Robotic Hands

In this paper, we present a novel three-degree-of-freedom (3-DoF) series-parallel hybrid mechanism for a robotic finger that is capable of abduction/adduction and flexion/extension. The series-parallel fingers proposed in the literature have either less than 3-DoF or the fingertip motion which cannot be controlled, since they are difficult to analyze kinematically. We present the complete position kinematics and differential kinematics of our proposed finger mechanism and show through simulation examples that the fingertip can be kinematically controlled to follow a given path. Both position control and velocity control capabilities are demonstrated.