Adaptive spacecraft relative position tracking control for non-cooperative target with thrust saturation

In the presence of the external disturbance, unmodeled dynamics and thrust saturation, this paper handles the spacecraft relative position tracking problem for non-cooperative target by using the line-of-sight (LOS) relative motion dynamics. By employing the anti-windup technique and nonsingular fast terminal sliding mode (NFTSM), the adaptive control law is proposed to guarantee the ultimate boundedness of the error state without prior knowledge of the upper bound of the external disturbance and system uncertainty. Finally, the numerical simulation is conducted to demonstrate the fine performance of the proposed control law.