Adaptive sliding mode attitude tracking control for flexible spacecraft systems based on the Takagi-Sugeno fuzzy modelling method

Abstract

This paper addresses the problem of adaptive sliding mode attitude tracking control for a class of nonlinear flexible spacecraft systems with a redundant four reaction wheels’ setting and unknown actuator dead-zone, where configuration misalignment and external disturbance are considered simultaneously. By using the Takagi-Sugeno (T-S) fuzzy modelling method, the overall nonlinear spacecraft attitude dynamics system is first reconstructed into several local linear systems. Then, an adaptive integral-type sliding mode control scheme is introduced based on a T-S fuzzy model to stabilize the considered attitude tracking control system of flexible spacecraft. In this design, the external disturbance with unknown bound is counteracted in real-time by the adaptive estimate technique. Additionally, the integral sliding surface we introduced is insured to be asymptotically stable under the condition of given matrix inequality. The proposed adaptive sliding mode controller guarantees the finite-time reachability of the specific sliding surface. A practical example with simulation results is given to verify the validity of the attitude tracking control strategy we put forward.