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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.

This paper investigates a finite-time attitude manoeuvre control problem for a flexible spacecraft subject to bounded external disturbances. A robust discontinuous finite-time controller with terminal sliding mode control is designed to solve this problem provided that the disturbances and the coupling effect of flexible modes are bounded with a known boundary. The controller is further enhanced by an adaptive scheme to deal with the more practical case that the boundary is unknown. The enhanced version is continuous and chattering-free. The results are rigorously proved using the Lyapunov stability theory. The effectiveness and robustness of the proposed controllers are demonstrated by numerical simulation.

To solve the problem of attitude synchronization for spacecraft formation with communication time-varying delays, this paper investigates a distributed attitude coordination tracking control strategy in which a directed graph contains a spanning tree with the leader as the root. Based on second-order consensus algorithm and graph theory, we propose a novel distributed attitude coordination control approach, which can regulate the attitude of spacecraft to a common time-varying reference states in case of time-varying delays. And the stability of the system is proved via Lyapunov Razumikhin theory. Simulation results demonstrate the effectiveness of the proposed control approach.

Based on active disturbance rejection control (ADRC)