Abstract: An underactuated Control method is proposed for the stabilization control of the postcapture combination with state constraints. First, On the basis of establishing the dynamic model of the tethered system, the auxiliary function is designed to ensure the state constraints, and an underactuated controller is designed based on the energy method. Then, it is mathematically proved that the system state satisfies the constraints and can converge to the expected value. Finally, the designed controller is verified by simulation and compared with the traditional hierarchical sliding mode controller. The simulation results show the superiority of the designed controller with smaller attitude angle change range, less convergence time and higher control accuracy during the control process.

Key words: tethered space robot, control of the combination, underactuated control, state constraints