Kinematics Analysis of A New 6-DOF Parallel Mechanism

Abstract

A new 6-DOF (degree of freedom) parallel mechanism with 2 limbs, namely 2-S~r RU, is presented; the S~r joint is a 3-DOF spherical mechanism, considered as a composite spherical joint, R is the revolute joint and U is the universal joint. The closed-form solutions of the forward solution is a 4~ th order polynomial. The two reasons for using the directional cosine matrix to represent the orientation are: first, unlik the Euler angles, such a matrix has no any representative singularities; second, there are no trigonometrical functions involved in the computation, Which means good computational efficiency. The new mechanism presented here can be used for robot arm; it has compact structure and can be easily modularized.