Adaptive control for hypersonic vehicle with input saturation and state constraints

The tracing control problem of hypersonic vehicle subject to external disturbances, parametric uncertainties, input saturation and state constraints. Firstly, the longitudinal model of the hypersonic vehicle is converted to the velocity subsystem and altitude subsystem based on the functional decomposition. Secondly, two adaptive anti-saturation controllers are proposed for the velocity subsystem and altitude subsystem with the unknown upper bound of external disturbances. By using the asymmetric barrier Lyapunov function, the two controllers can make flight path angle, angle of attack and pitch angle rate keep within the certain ranges. Meanwhile, the auxiliary system is introduced to deal with the problem of input saturation and a low-pass filter is designed to avoid the "explosion of terms" in traditional backstepping control caused by the complicated differentiations of the virtual control signals. Finally, the effectiveness of the presented control strategy is verified by the Lyapunov stability theory and numerical simulations results. (C) 2018 Elsevier Masson SAS. All rights reserved.