Continuous nonlinear asymptotic tracking control of an air-breathing hypersonic vehicle with flexible structural dynamics and external disturbances

Abstract

In this paper, the tracking control problem of an air-breathing hypersonic vehicle with structural flexibility is addressed. Due to the harsh high Mach flight condition, the influence associated with the dynamic flexible modes of the hypersonic vehicle cannot be neglected. These flexible dynamic modes, which are affected by the vehicle’s states and control surface deflections, can be viewed as an internal dynamics associated with the system outputs. A new nonlinear robust continuous tracking controller is developed to drive the vehicle’s outputs, which include the vehicle’s velocity, altitude, and attack angle, to track the desired time-varying trajectories in the presence of flexible structural dynamics, parametric uncertainties, and external nonvanishing disturbances. A Lyapunov-based stability analysis is employed to prove that the proposed control design can achieve asymptotic tracking while keeping the internal dynamics to be bounded-input/bounded-output stable. Numerical simulations are performed on the full nonlinear dynamic model to demonstrate the tracking performance of the controller, and highlight the robustness with respect to parametric uncertainties and external disturbances.