New adaptive sliding mode control for a generic hypersonic vehicle

The work presented here is concerned with the robust flight control problem for the longitudinal dynamics of a generic hypersonic vehicle under mismatched disturbances using adaptive sliding mode control with a nonlinear disturbance observer. A simplified control-oriented dynamic model is built with curve-fitted approximations. Based on the mismatched disturbance estimated by a nonlinear disturbance observer, a novel adaptive sliding mode control is proposed to stably track the velocity and altitude reference trajectory with back-stepping technique. The stability analysis of the closed-loop system and convergence of the system are verified based on Lyapunov stability theory. Finally, simulation results from the nonlinear model of hypersonic vehicle indicate that the proposed method can obtain promising robustness and disturbance rejection performance.