Abstract:

This paper focuses on controller design for the tethered satellite systems. The dynamic equations of the tethered system in orbital maneuvering are established and the in-plane motion is formulated as a typical underactuated system. In order that the underactuated system can be forced to track the expected in-plane angle trajectory, an integrator chain system is derived for a redefined sliding surface and a tether tension control law is proposed based on a novel high-order sliding mode. This control law guarantees high-accuracy tracking and provides a chattering-free performance. After the establishment of a high-order sliding mode with respect to the redefined sliding surface in finite time, the closed-loop system is linearized at the equilibrium point. Afterwards, the closed-loop system is proved locally and asymptotically stable based on the Routh Criterion. Simulation results demonstrate the usefulness and effectiveness of the proposed control methodology.

Key words: Tethered satellite, Orbital transfer, Novel high-order sliding mode, Linearization, Chattering-free