Finite‐time attitude‐orbit integrated tracking control of flexible spacecraft under input saturation

Abstract

This paper investigates the attitude-orbit integrated modeling and robust control of flexible spacecraft with input saturation. First, the dual-number method is employed to describe the dynamic model of the spacecraft with the flexible appendage. Then, a fast terminal sliding mode control law is designed to stabilize the attitude-orbit control system of the spacecraft. In addition, considering the input saturation, a time-varying siding surface based terminal sliding mode control law is further proposed to solve the design problem. Under the designed control laws, the state trajectories of the attitude-orbit coupled control systems can achieve to be finite-time stable, and the reachability of the proposed sliding surface can be ensured at the same time. Finally, through numerical simulations and comparison with the conventional methods, the superiority of the proposed control strategies in convergence speed and convergence accuracy is verified, and the feasibility of engineering application is verified.

Robust adaptive finite‐time control design for the generation of stable oscillations in the strict‐feedback form non‐linear systems with input dead‐zone non‐linearity

“…In recent decades, the concept of finite-time control has arisen significantly in different fields of engineering [1][2][3][4][5]. The wellknown feature of finite-time stability is that it forces the system's states to reach an equilibrium point in a finite time and stay there afterwards.…”