Adaptive position and attitude tracking control for satellite proximity operations using sliding mode and time delay estimation

In this paper, a novel approach to the tracking control problem of the satellite proximity operations between a leader and a follower satellite is presented. First, the Lagrange-like model of the satellite relative motion is derived by using proper operators which introduced in dual quaternion context. Then, considering this model, a nonlinear adaptive controller is developed by combining the sliding mode control and time delay estimation technique. The proposed control strategy eliminates the necessity of prior information on the uncertainty bounds in the system. Using the Lyapunov's second method, the asymptotic convergence of both the relative position and attitude tracking errors is guaranteed. The numerical simulations show the superior performance of the developed control method regarding the convergence rate and the steady-state tracking precision compared to a previous control technique in the literature.