A sequential method for the singularity free workspace design of a planar 3-arm parallel robot

A method to design a singularity-free 3-arm planar parallel mechanism is presented. Parallel mechanism singularities are categorized by their relationship to the design problem. A sequential design procedure is explained, whereby two arms are designed first to satisfy workspace requirements, then the third arm is designed to provide a singularity free workspace. The method is used to develop a singularity-free workspace design for the 3-RPR mechanism.