Fuzzy adaptive sliding-mode control for hypersonic vehicles

This study focuses on a novel anti-disturbance flight control scheme for the near space hypersonic vehicle (NHV) based on the fuzzy sliding-mode control technique and disturbance observer. First, a fuzzy system is employed to approximate the uncertainty nonlinear dynamics; furthermore, an auxiliary fast dynamic observation system is introduced to tackle the system uncertainty and the time-varying unknown external disturbance of the NHV. Second, the dynamic adaptive terminal sliding-mode control strategy is raised to alleviate the chattering phenomenon. Third, the Lyapunov method is used to prove that the adaptive control system can be guaranteed to be stable and the tracking errors are converged in finite time. Finally, the effectiveness of the proposed method is verified with simulation.