Finite-time attitude control for flexible spacecraft with unknown bounded disturbance

This paper studies finite-time attitude control for a flexible spacecraft with unknown bounded disturbances. Aiming at reducing vibrations excited by attitude manoeuvring, we develop a new manoeuvre path by combining path planning with the input shaping technique. Also, based on terminal sliding mode and the exponential reaching law, we propose a modified fast non-singular finite-time control law, which can achieve rapid finite-time convergence in the reaching phase as well as in the sliding phase. Furthermore, we design a weighted homogeneous extended state observer to estimate and thus to attenuate the unknown bounded disturbances in finite time. Finite-time stability of the overall system is analysed via Lyapunov technique, and simulation results demonstrate the effectiveness and robustness of the proposed control scheme.