A sequential method for the singularity-free workspace design of a three legged parallel robot

A method to design a singularity-free 3-arm planar parallel mechanism is presented. Single-arm and two-arm singularities are addressed for design purposes. 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.