Adaptive Coordinated Control For Air-breathing Hypersonic Vehicle With Variable Geometry Inlet

Air-breathing hypersonic vehicle(AHV)is significant for ensuring national strategic security,which can achieve fast and accurate global strategic strikes with the characteristics of super-high speed and long distance.However,once the AHV is operated at a low Mach,the conventional structure of the AHV with a fixed geometry scramjet inlet will affect the maneuverability of the AHV.Therefore,this paper adopts the structure of the variable geometry scramjet inlet,to improve the performance of AHV,by the expansion and contraction of the inlet.In this paper,the main research contents for the AHV with variable geometry inlet(AHV-VGI)are as follows:Considering that the aerodynamic parameters of AHV-VGI are uncertain and time-varying.This work adopts the identification algorithm based on extended kalman filter and maximum expectation algorithm to identify the aerodynamic parameters of the model on-line,to modify the aerodynamic model established by curve fitting,and provide the accurate model basis for the controller design in the following chapters.In addition,for the problem of coordinated control between translating cowl with stepping switching and stable flight of AHV-VGI,a multi-model control is proposed.The nonsingular terminal sliding mode control(NTSMC)is used to design subcontrollers,and the adaptive Type-2 fuzzy system is adopted to design the controller in the switching process.Through the simulation results,it is proved that the proposed control method based on the smooth switching strategy has good tracking performance.Furthermore,this paper also studies the coordinated control between continuous control of translating cowl and stability control.Considering the uncertainty of model introduced by the translating cowl,an adaptive fuzzy controller is designed for the AHV-VGI.Besides,because the AHV-VGI will be affected by external disturbances in actual flight,a fixed-time disturbance observer is designed to compensate the designed fuzzy controller,to improve the robustness of the system.The simulation results show that the fuzzy controller based on fixed-time disturbance observer has better robustness.