Workspace and Kinematics Analysis of a 2-DOF Decoupled Spherical Parallel Mechanism

A 2-DOF (degree of freedom) decoupled spherical parallel mechanism is presented. The mechanism´s configuration characteristic are studied and summarized. Its branch-chains are different completely, one is a 1/4 circular branch-chain, the other is a 7R+ R branch-chain, and each branch-chain can only control one rotational direction of the movable platform. Furthermore, in order to verify the mechanism´s decoupling characteristic, the mechanism´s kinematics analysis is completed, which is concerned with the direct/inverse kinematics problems, the input/output speed and the acceleration analysis. Finally, the workspace of the parallel mechanism is analyzed systematically. All these works provided the significant theory for the further study of the mechanism´s application. The decoupled spherical mechanism has wide application in the fields of the robot´s waist, wrist, shoulder, hip and antenna orientation, camera tracking, solar localization et al.