Nonlinear disturbance observer enhanced predictive control for airbreathing hypersonic vehicles

The robust optimized tracking control problem for a generic airbreathing hypersonic vehicle (AHV) subject to nonvanishing mismatched disturbances/uncertainties is investigated in this paper. A baseline nonlinear model predictive controller (MPC) is firstly introduced for optimized tracking control of the nominal dynamics. A nonlinear disturbance observer (NDO) based control law is then developed for robustness enhancement in the presence of both external disturbances and uncertainties. Compared with the existing robust tracking control methods for AHVs, the proposed composite nonlinear MPC method obtains not only promising robustness and disturbance rejection performance but also optimized nominal tracking control performance. The merits of the proposed method are validated by implementing simulation studies on the AHV system.