Design of blended control strategy for autonomous aircrafts with multiple actuators

A blended control strategy for autonomous aircrafts with multiple actuators is proposed in this paper. The strategy is divided into aerodynamic control subsystem and reaction jet control subsystem (RCS). Due to the complex nonlinearities, large uncertainties and strong coupling, the aerodynamic subsystem controller is designed by applying feedback linearization based on the theory of time-scale separation and sliding mode control theory. The RCS consists of four parts that are error dynamic adjustment model, PD controller, firing logic algorithm and reaction jet model. The RCS, which corresponds with the actual engineering characteristics of attitude control motors (ACMs), is designed to improve the response performance. Simulation results with a nonlinear six-dimension aircraft model show the blended control strategy has a higher tracking precision and a much more improved response characteristic than pure aerodynamic control. Simultaneously the robustness for the aerodynamic coefficient uncertainties and jets interaction is strong.