Coordinated approach control method of tethered space robot system

The tethered space robot system (TSR) will play a significant role in future on-orbit capture. In this paper, the approach model is derived and the coordinated approach control method is studied which contains an optimal open-loop controller and a feedback controller. The optimal open-loop control law is designed by Gauss pseudospectral method. Then, the approach model is linearized along the open-loop trajectory and the feedback controller is designed by linear quadratic regulator which is simpler and more efficient than the popular recedinghorizon controller. The simulation results show that the approach control method is effective, even in the presence of initial perturbations, the tracking errors of tether tension and other disturbances.