Robust adaptive control for hypersonic gliding vehicles based on NESO

In the reentry stage, the hypersonic gliding vehicle (HGV) has the obvious characteristics like high-dynamic, large flight envelop, complex flight environment and so on. These features result in severe parameter uncertainties. In order to improve the attitude control performance in reentry stage, the sources of the uncertainty and the unknown parameters are analyzed. Then a robust adaptive controller is established to cope with the parameter uncertainty problems. Three parts are included in this control system, which are the nominal controller, the nonlinear extended state observer (NESO), and the compensation controller. The nominal controller is constructed by using the nonlinear dynamic inversion (NDI) method. NESO is introduced to estimate the unknown parameters. On the basis of the NESO, the compensation controller is built and used to eliminate the effects caused by the parameter uncertainty. The stability of designed robust adaptive controller is proven by using the Lyapunov theory. The nominal controller and compensation controller are used together to guarantee the tracking attitude performance of the HGV. The effectiveness and performance of obtained theoretical results are demonstrated by using a numerical example.