Lyapunov-based output feedback control of hypersonic vehicle

In this paper, an output feedback controller is designed for the longitudinal dynamics of a hypersonic vehicle, under the restriction that only partial information can be measured. The high gain observer (HGO) is utilized to estimate the signals for immeasurable derivatives of the vehicle´s velocity and altitude, and a radial basis neural network (RBNN) based feedforward function is designed to compensate for the model uncertainties. A Lyapunov-based comprehensive stability analysis of the closed-loop system is presented, and the proposed control law is proved to be yielding semi-global uniformly ultimately bounded, while keeping all the closed-loop signals bounded. Numerical simulation results are also presented to validate the control design.