The prescribed time sliding mode control for attitude tracking of spacecraft

TLDR

Space missions increasingly require prescribed‑time convergence, but integrating this with sliding‑mode control is challenging due to infinite gains near the prescribed time and dual sliding‑mode periods. The paper proposes a prescribed‑time sliding‑mode control method for general systems with matched disturbances, aiming to enable attitude tracking of spacecraft. A novel sliding‑mode variable incorporating an explicit time term is designed to achieve prescribed‑time convergence, and a disturbance‑observer‑based controller is employed for spacecraft attitude tracking. The proposed method avoids singular control inputs as the prescribed time is approached and demonstrates improved performance in numerical simulations.

Abstract

Abstract With the development of the space missions, there are extensive missions in the demand of the prescribed time convergence. However, it's still a difficult work to combine the prescribed time method with the sliding mode control due to the infinite gain of the prescribed time method while approaching the prescribed time and two periods of sliding mode control. In this paper, a new prescribed time sliding mode control method is proposed for general systems with matched disturbances, from the second‐order system to the high‐order system. A novel sliding mode variable with explicit time term is designed for achieving the prescribed time convergence. More importantly, as time approaches the prescribed time, the singularity of control input can be avoided. Finally, this paper presents a disturbance observer‐based prescribed time sliding mode control method for attitude tracking of spacecraft, and the efficiency of this method has been verified through the numerical simulations.