Research On Sliding Mode Control Method Of Air-breathing Hypersonic Vehicle

In recent years,hypersonic vehicle has attracted much attention in the field of aerospace and military because of its high speed and long range.While helping the glide technology mature and move toward deployment and actual combat,countries have also accelerated the capital and technology investment of the aspirated hypersonic technology.Due to the coupling of aerodynamic thrust system and strong nonlinear problems in the flight process,the design of the control system of the airbreathing vehicle has become an urgent problem to be solved.This paper focuses on the flight control problems of the air-breathing hypersonic vehicle in the climbing and cruizing stage,mainly including the following research contents:For controller design and analysis of the basis,describes the appearance of airbreathing hypersonic flight vehicle structure and ballistic characteristics,define the flight mechanics related coordinate system and the transformation of the relationship between construction of super combustion stamping a thrust model and dynamic model of the fuselage suffer indignities,through mathematical derivation and empirical analysis of vehicle longitudinal dynamics and kinematics model is established.To solve the air-breathing hypersonic flight vehicle strongly nonlinear and overcome a wide range of parameter uncertainties,using higher-order superhelix algorithm based on sliding mode theory to design a kind of suitable for air-breathing hypersonic flight control law,first by linearization,the dynamic model described as affine form,based on the feedback will push the coupling relationship removes gas,Then through robust tracking differentiator output variable error and its derivative,can make the tracking error convergence in a limited time,solve the problem of parameter uncertainty and higher-order superhelix controller is designed,through the simulation,the controller can realize accurate tracking of aircraft to the control instruction at the same time,ensure flight process robustness to external disturbance,as a result of the existence of high order sliding mode at the same time,Buffeting is effectively suppressed.A fuzzy integral sliding mode control strategy based on T-S fuzzy model was proposed for the strong nonlinearity and parameter uncertainty of the aspirated hypersonic vehicle.Firstly,the T-S fuzzy model of the aspirated hypersonic vehicle is established to describe the nonlinear longitudinal model.A fuzzy integral sliding surface is proposed,and the dynamic characteristics and robustness of the sliding surface are analyzed.Based on the parallel distributed compensation(PDC)method,an equivalent control method was designed,and sufficient conditions were given to ensure the stability of equivalent dynamics on the integral sliding surface.Then the adaptive sliding mode control law is integrated to ensure the accessibility of the specified sliding mode surface under the condition of nonlinear input.Finally,the validity of the proposed control method for the AHV in the climbing cruise section is verified by the simulation of various working points and the full climbing cruise section.