Non-Singular Fast Terminal Sliding Mode Control with Super-Twisting ESO for Spacecraft Formation Flying Systems

In this article, we analyze how spacecraft formation can save more fuel and achieve more accurate relative position motion in the configuration control under the influence of external disturbances and perturbations. A non-singular fast terminal sliding mode controller(NFTSMC) combined with Super-Twisting extended state observer(STESO) is proposed for disturbance rejection control of spacecraft formation configuration. In this paper, we will establish the kinematics model of spacecraft relative motion, and linearize this model. Then, the convergence of STESO and the stability of the combination of NFTSMC and STESO are analyzed respectively. Finally, sufficient numerical simulations will be provided to verify the feasibility of the algorithm.