A geometric approach for the design of singularity-free parallel robots

While a number of researchers have published results in the area of parallel robot singularity determination and the a posteriori elimination of these singularities, far less work has been published in the area of singularity free workspace design. Several researchers have committed substantial funds to design hardware prototypes that have proven worthless because of unavoidable singularities. This trend, if carried over to industrial applications, could prove especially detrimental to the future of applied parallel robotics. A comprehensive and straightforward design strategy that guarantees a singularity free workspace is presented in this paper. The design problem is mathematically modeled, and relaxations are suggested for finding solutions. The translational 3-UPU parallel robot is studied to verify the efficacy of the design approach.