Disturbance observer based compound control for an air-breathing hypersonic vehicle

A compound control method based on disturbance observer compensation and global fast terminal sliding model control is proposed for an air-breathing hypersonic vehicle (AHV) with considering matching uncertainty and model coupling that existed between longitudinal and lateral-directional. Firstly, we design robust tracking controller for the AHV using nonlinear dynamic inversion and global fast terminal sliding model control method. The terminal sliding model guaranteed the states of flight system converge in limited time, which speeds up convergence of tracking error. Secondly, model coupling is considered as external disturbance and wavelet neural network disturbance observer is used to approximate disturbance and inversion error in order to compensate robust tracking controller. Finally, Numerical simulations have demonstrated the effectiveness of the proposed approach.