Switched-model-based compound control of hypersonic vehicles with input nonlinearities

Focusing on the large-envelope control problem of air-breathing hypersonic vehicles (AHVs), this paper employs a switched control-oriented model (SCOM) to describe vehicle dynamics over the flight envelope, while using reaction control system (RCS) to enhance the controllability of AHVs especially flying at a high altitude. A novel SCOM-based compound control is developed to accommodate uncertainties, as well as to fuse the continuous aerodynamic control surface (ACS) and discrete RCS, adaptively. Theoretical analysis indicates that the presented ACS–RCS compound control is capable of stabilizing SCOM and therefore is valid over the whole flight envelope, which is the main advantage in comparison with the existing controllers of AHVs. In addition, practical input nonlinearities in fuel-to-air equivalency ratio, ACS, and RCS are considered, synthetically, making the proposed control more applicable to a real scenario.