Force-Pose Stability Measures and Specified Stability Workspace Generation Techniques for Cable-Driven Parallel Robots

Cable-driven parallel robots (CDPRs) have attracted much attention due to a lot of advantages over conventional parallel robots. One of the main issues is the stability of the robot, which employs cables with strong flexibility and unidirectional restraint to operate the end-effector leads. As a result, this presented article aims to propose a systematic approach to the stability measures for the CDPRs by means of combining the cable tensions and poses of the end-effector. First, two position-influencing factors having important effects on the stability of the CDPRs are presented based on their kinematic model. Then, two cable tension-influencing factors also having essential effects on the stability of the robot are developed based on the determinations of cable tensions. Meanwhile, a function representing the effects of the end-effector's attitudes on the stability of the robots is constructed. Furthermore, the stability measures for the CDPRs are addressed, where a systematic stability measure approach is presented and three stability measure applications, average stability, minimum stability, and weighted average stability, are presented. Subsequently, a specified stability workspace is designed with the proposed force-pose stability measure approach. Finally, the approach to the force-pose stability measures and specified stability workspace generation algorithm are explained through simulation results of a spatial cable-driven parallel robot with 6-DOF with eight cables.