Sliding mode disturbance observer-based adaptive tracking control for hypersonic reentry vehicle

Aiming at attitude tracking control for hypersonic reentry vehicle, an adaptive backstepping controller based on sliding mode disturbance observer is proposed in this article. First, the strict-feedback nonlinear model with uncertain aerodynamic parameters and external disturbances for the hypersonic reentry vehicle is established. Then, a sliding mode disturbance observer is designed to estimate external disturbances for the proposed controller. In addition, the adaptive backstepping controller with the sliding mode disturbance observer is proposed, in which adaptive strategies are used to estimate the uncertain aerodynamic parameters online. Finally, according to the Lyapunov theorem, the tracking errors of the closed-loop attitude stabilization system are proved to be ultimately bounded. Simulation results show that the proposed controller can achieve adaptive tracking control under the influences of parameter perturbation and external disturbances.