Dynamic Response of Spatial Flexible Structures Subjected to Controllable Force Based on Cable-Driven Parallel Robots

Abstract

Certain satellites with ultralong wings play a crucial role in many fields. However, external disturbance and self-rotation could result in the vibration of flexible wings, which affects the normal operation of the satellites. In severe cases, the satellites will be damaged. Therefore, the vibration of these spatial flexible structures should be suppressed. With the benefits of large workspace, low energy consumption, and small inertia, a cable-driven parallel robot (CDPR) is proposed for vibration suppression of ultralong spatial flexible structures. A controller based on the open-loop control is proposed in this article to rapidly suppress the vibration of flexible structures with quite small controllable force. To enhance the contrast, two sets of passive pretightening schemes (wire ropes and elastic strings with small elastic coefficients) are tested. In view of the small value of the cable force, the influence of friction on the experiment cannot be neglected. Therefore, a friction measurement experiment is also carried out to ensure the accuracy of the experimental data. First, the dynamic model of the CDPR, which is comprised of four cables and a flexible end-effector is established. Furthermore, controller design is detailed. The dynamic response of the scale model under output force of the control low is compared with free vibration, which validates the scheme's ability and effectiveness in vibration suppression. Finally, simulations and experiments are conducted to evaluate the control scheme, and the results are satisfactory.