Finite-time distributed cooperative attitude control for multiple spacecraft with actuator saturation

In this study, the distributed cooperative attitude tracking controller based on fast terminal sliding mode and Chebyshev neural network (CNN) is proposed for multiple spacecraft formation flying (SFF) system in the presence of external disturbance. Firstly, a new modified fast terminal sliding mode manifold, which has faster convergence rate than the existing terminal sliding modes, is proposed. Then, based on the proposed terminal sliding mode manifold, the distributed cooperative attitude tracking controller is designed for the SFF system, where the time varying reference attitude can be only accessed to a subset of the group member. To guarantee that the output of CNN used in the controller is bounded by the corresponding bound of the approximated unknown function, a modified adaptive law is proposed to revise the sliding mode manifold, meanwhile, the finite-time stability of SFF system can be also guaranteed. Finally, numerical simulations are presented to verify the validity and robustness of the proposed control algorithm.