A New Class of Four-DOF Cable-Suspended Parallel Robots Based on Parallelogram Arrangements of Cables

This paper proposes for the first time the original architecture of a cable-suspended parallel robot (CSPR) with four degrees of freedom (dofs). This new class of 4-dof CSPR is inspired by the existing types of rigid parallel robots. It utilizes four pairs of parallelogram cables to generate a motion pattern with three translations and one rotation. Each pair of parallelogram cables is actuated by one independent motor for the purpose of maintaining equal length. The correctness of the motion pattern is validated through a mobility analysis based on screw theory. Preliminary results of the workspace analysis for this type of CSPR are presented as well.