Kinematic Analysis and Manipulability Evaluation of a 4-DOF Parallel Gripper for Dexterous Manipulation

This paper presents a novel design for a robotic end-effector. In particular, the design features a 4-DOF parallel gripper potential of applying for industrial automation. This gripper mainly consists of two parallelogram mechanisms and two grasp sliders, which can perform in-hand twisting action (in-hand manipulation) and in-plane horizontal and vertical transmission. Moreover, the proposed gripper adopts parallel grasping mode and can provide stable ability to maintain force closure on an object with large ranges of size. The kinematic analysis which includes position solution and velocity solution is derived. The velocity manipulability that possesses the physical significance of energy transfer efficiency is defined. A numerical example is presented to evaluate the performance of the gripper. The results indicate that the gripper can achieve horizontal transmission to supplement the workspace of the robot arm, and possess relatively better performance on in-hand manipulation and in-plane vertical transmission.