Topological and Kinematic Performance Analysis of a Class of 5-SPS Parallel Mechanisms With Line Moving Platform

This paper is to design a class of manipulators capable of producing five DOF (degree-of-freedom) output motion for controlling the position and orientation of a line. Four novel 5-SPS parallel mechanisms with LMP (Line Moving Platform) are proposed according to the structure coupling-reducing principle proposed by authors on the basis of an existing 5-SPS parallel mechanism with LMP. Three key topology characteristics, such as structure coupling degree, output position and orientation characteristics, input-output kinematic decoupling, and the position workspace characteristics, as the fourth characteristic, of these five 5-SPS parallel mechanisms with LMP are calculated and compared respectively. It shows that the use of concentric spherical joints on the moving platform can reduce coupling degree of mechanisms and simplify the forward displacement and the workspace analysis. The mechanisms with triple-spherical-joint structure have input-output motion decoupling. Therefore, each of the 5-SPS parallel mechanisms with LMP has its own advantages and applications. This paper provides a foundation for engineering design, optimal selection and potential application of the five 5-SPS parallel mechanisms with LMP.