PKS 2002 Tagungsband.vp

This paper presents a new 4-degree-of-freedom parallel mechanism dedicated to handling of heavy parts within a large workspace. These 4 degrees of freedom are 3 translations and 1 rotation about a given axis. Such a mechanism is rare; most of common parallel mechanisms have 3 or 6 degrees of freedom. Firstly, a description of the mechanism is given. Then models are derived regarding velocity and force transformation as input-output relationships. Finally, internal forces models and stiffness model are evaluated. All models are embedded in a software module aiming to help with preliminary design of machines based on this new architecture. 1 Notation I3 identity matrix of rank 3 pre(X) pre-cross-product matrix associated to vector X Pi point Pi Pi vector containing Cartesian coordinates of point Pi P matrix containing Cartesian coordinates of all points Pi Development 151