Robust adaptive control for rotational deployment of an underactuated tethered satellite system

This paper proposed a novel underactuated control scheme to deal with the rotational deployment of a dual-body tethered satellite system without using tangential force acting on the tether. To describe the spin motion of the system during tether deployment, the parent satellite is modeled as a rigid body. An underactuated robust control framework is developed to govern the rotational deployment of the system in the presence of disturbances and model uncertainty. The adaptation update laws are designed to adjust the gain of the robust term of the controller, thereby improving the anti-interference ability of the system to cope with the perturbations stimulated by the spinning of the parent satellite. The underactuated rotational deployment controller theoretically guarantees the stability of motion of the entire system, that is, the uniformly ultimate boundness of the closed-loop control system can be strictly proven using Lyapunov theory. Finally, simulations are performed to validate the effectiveness of the proposed control scheme.