Abstract:

 According to the three-channel attitude tracking control problem of the near-space hypersonic vehicles, a nonlinear fuzzy adaptive sliding-mode controller based on the input saturation restraint is proposed. Considering the characteristic that the model of a flight vehicle has a strict-feedback form, the controller is designed based on the backstepping method combined with the nonsingular fast terminal sliding-mode control method. Two fuzzy systems are designed to estimate the disturbances of the model, and the estimative errors are compensated via the adaptive robust terms. The nonlinear gain function is adopted to improve the saturation restraint capability of the control system. The stability of the closed-loop system is proved based on the Lyapunov theory. Finally, the validity of the proposed method is verified via a simulation comparison experiment. The simulation results show that the proposed controller can guarantee good attitude tracking performance and input saturation restraint capability of the flight control system containing the uncertainties of the model parameters.

Key words: Near space hypersonic vehicle, Flight control, Backstepping, Fuzzy system, Adaptive control