Singularity-free fully-isotropic translational parallel manipulators

This paper focuses on translational parallel manipulators (TPMs), that is on parallel manipulators whose output link (platform) is provided with a pure translational motion with respect to the frame. It deals with the general problem of the topological synthesis and classification of TPMs and investigates both their constraint and direct singularities. In particular, it identifies for the first time special families of fully-isotropic mechanisms. Such manipulators exhibit outstanding properties, as they are free from singularities and show a constant orthogonal Jacobian matrix throughout their workspace. As a consequence, both the direct and the inverse position problems are linear and the kinematic analysis proves straightforward. Copyright © 2002 by ASME.