Analysis of the Stiffness Feasible Workspace of the Cable-Driven Parallel Robots

In this paper stiffness of the cable-driven parallel robot is analyzed and then the concept of the stiffness-feasible workspace is presented based on internal forces. Analysis of wrench closure workspace and stiffness matrix for determined values of internal forces in all over of the fixed frame will determine this workspace. The proposed approach gives a range of internal forces that can improve the stiffness of the robot. Since the proposed workspace depends on the structure of robot, geometrical parameters of the robot are optimally designed to maximize stiffness-feasible workspace and wrench closure workspace. At the end, simulation results on a planar cable robot are presented to verify operation of the robot in the stiffness-feasible workspace by designed geometrical parameters.