New 3-DOF Parallel Mechanism and Application to Space-Born Smart End-Effector

A new three-degree-of-freedom parallel mechanism called PMP (Parallel Moving Platform) is devised to develop a smart end effector which adds dexterous capability to a long space manipulator. The PMP consists of a platform connected to a fixed base by three linear actuators and three parallel constraint mechanisms, and it has the advantages of compactness, simple kinematic relation, and translational mobility in the direction of approach. The kinematics are expressed by simple algebraic formulations. This paper deals with the kinematics analysis of the PMP and its application to the smart end effector. The forward and inverse transformation, singular configuration, and work space analysis of the mechanism are described. Moreover, the development of the smart end effector using the combination of the PMP and a 3-axis gimbal, and experiment results are presented.