Coordinated attitude control of the combination system after target capture by a tethered space robot

The coordinated attitude control of the combination system after the target is captured by the Space Tethered Robot is studied in this paper. Firstly, a combination system dynamic model is established and its dynamic characteristics are analyzed. Secondly, taking into consideration such combination system characteristics as the limitation of fuel and thruster force, two attitude controllers are designed: one is the coordinated controller of the tether force and thruster force and the other the sliding mode controller of the thruster force only. The combination system attitude is controlled by these two controllers which are utilized according to the switch condition. Finally, the numerical simulation is conducted to validate the feasibility of the proposed coordinated control method. The simulation result shows the combination system attitude can be controlled by the coordinated control method and the fuel consumption is effectively reduced.