Kinematic analysis and design of a six DOF 3-PRPS in-parallel manipulator

This paper presents a kinematic analysis and design characteristics of an i n-parallel manipulator developed for the probing task application that requ ires high precision, active compliance, and high control bandwidth. The dev eloped manipulator is a class of six-degree-of-freedom in-parallel platform s with 3 PRPS (prismatic-revolute-prismatic-spherical joints) chain geometr y. The main advantages of this manipulator, compared with the typical Stewa rt platform type, are the capability of pure rotation generation and the ea sy prediction of the moving platform motion. The purpose of this paper is t o develop an efficient kinematic model which can be used for real-time cont rol and to propose systematic methods to design the manipulator considering workspace, manipulability, resistivity, singularity, and the existence con ditions of the forward kinematic solution. Particularly, we propose a new m ethod for checking the singularity of the parallel manipulator using the tr anslational and rotational resistivity measures. A series of simulation are carried out to show kinematic characteristics and performance of the manip ulator mechanism. A prototype manipulator was built based on the kinematic analysis results.