Coordinated coupling control of tethered space robot for considering releasing characteristics of space tether

According to the tracking optimal trajectory control problem of the tethered space robot(TSR) for approaching the target, a coordinated coupling control method for considering releasing characteristics of the space tether is proposed. This method considers the dynamic characteristics of releasing tether, the releasing velocity of tether can be taken as planning input towards optimal trajectory planning, and the releasing mechanism torque can be seen as one control input. The 6-DOF coordinated coupling controller is designed with the help of thruster control input and releasing motor control input for tracking optimal trajectory and desired attitude. It is easy to impose and achieve engineering application for the auxiliary control of the space tether by utilizing the proposed method. The simulation results show that the TSR can track optimal trajectory accurately, and the terminal error is ±0.1 m. Furthermore, the TSR can track the desired attitude effectively, and the error is ±0.2°.