Analytical Identification of Limb Structures for Translational Parallel Manipulators

A systematic analytical method, based on the theory of screws, is presented for identification of limb structures of general and over-constrained 3-degree-of-freedom (DOF) translational parallel manipulators. Given a system of wrenches of constraint, the corresponding reciprocal basis screws are determined. Then, the joint screws of a limb are obtained by a linear combination of these basis screws. Feasible limbs that can be used for construction of translational platforms are enumerated according to the type of constraint and the number of joints making up the limbs. © 2004 Wiley Periodicals, Inc. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •