A spherical parallel manipulator (also called an orientational parallel manipulator or rotational parallel manipulator) refers to a threedegree-of-freedom (3-DoF) parallel manipulator in which the moving platform undergoes a 3-DoF spherical motion or rotates about a fixed point. In this paper, we propose a new method for the type synthesis of non-overconstrained (isostatic) spherical parallel m...

It is well known that singular configurations are an inherent nature of mechanical systems and have important influences on their properties. Therefore, these special configurations of the system are usually avoided in design and application of mechanisms. For simple 2-DOF and 3-DOF planar manipulators, the singularity loci have been obtained in [1, 2]. For spherical 3DOF parallel manipulators ...

In this paper we determine all non-trivial self-motions of TSSM manipulators with two parallel rotary axes which equals the determination of all flexible octahedra where one vertex is an ideal point. This study also closes the classification of these motions for the whole set of parallel manipulators of TSSM type. Our approach is based on Kokotsakis meshes and the reducible compositions of sphe...

Abstract: This paper presents a performance metric for the manipulability of constrained serial manipulators. The manipulability measure and manipulability ellipsoid are found from the manipulability Jacobian, which is easily found for serial manipulators as the standard Jacobian matrix, or for parallel manipulators as the Jacobian that gives the mapping from the active joint velocities to the ...