The Robust Maneuver Flight Control of Hypersonic Glide Vehicles with Input Saturation Using Disturbance Observer

In this paper, the maneuver flight control scheme is proposed for the hypersonic glide vehicle (HGV). The system uncertainty, unknown external disturbances and input saturation are explicitly considered in the controller design. Firstly, the maneuver control architecture of lateral turning for the HGV is developed, and then a robust attitude controller is constructed to execute the maneuver command accurately. To estimate the system uncertainty and unknown external disturbances, this paper presents a modified nonlinear disturbance observer (MNDO) which can guarantee that the estimate error signals are uniformly ultimately bounded. Secondly, an auxiliary design system is constructed to reduce the adverse effect of input saturation. Based on the developed MNDO and the auxiliary system, a robust attitude controller is designed for the HGV using the backstepping method. The tracking error is proved to be uniformly ultimately bounded by the Lyapunov method and its bound is adjustable. Finally, simulation results show the effectiveness of the proposed robust maneuver flight controller.