Sliding mode control for satellite proximity operations with coupled attitude and orbit dynamics

In this article, the high precision control problem of relative motion for satellite proximity operations is considered. First, attitude and orbit coupled dynamic models are established. Then, by choosing proper sliding mode surface, a novel sliding mode attitude controller is proposed, which is robust to disturbing torque brought by thrust misalignment and can guarantee attitude tracking errors converge in finite time. By employing the theory of non-singular terminal sliding mode, a robust relative orbit controller is proposed as well, which also has the property of finite time convergence. Numerical simulation demonstrates the validity of the presented control strategies.