Control and Residual Vibration Suppression of a Cable-Suspended Parallel Robot with Elastic Cables

The control of flexible cable-driven parallel robots usually requires not only the feedback from the joints, but the feedback from the end-effector pose or cable tension. This paper presents a new approach for reducing the vibration of flexible cable-suspended robots, using only the feedback from the joints. The dynamic equations of a 6DOF cable-suspended parallel robot with elastic cables are presented. The feedback linearization method based on the rigid model of the system is considered for the slow dynamic movement of the system. In order to reduce the vibration caused by the cable flexibility, a filtration method is employed to prevent excitation of natural modes. Thus, a combination of feedback linearization together with input shaping is employed in this paper to control the spatial cable robot with elastic cables. Simulation results demonstrate the effectiveness of the proposed approach in reducing the end-effector vibration by 92.1 % in the translational motion.