考虑推进和气动弹性影响的高超飞行器的建模与控制

摘要

针对高超声速飞行器飞行的速度和高度跨度大、变化快,飞行动力学特性复杂;模型具有非线性,强耦合及不确定性的特点,建立了考虑推进及弹性影响的纵向模型,并提出了纵向模型的鲁棒协调控制器设计方法.该方法在典型高超声速飞行器几何结构基础上,针对机体/发动机一体化设计布局,结合高超声速气动力学和气动弹性有关理论,建立非线性纵向模型;通过分析模型的不确定性来源,对刚体-弹性耦合系统设计了基于线性二次型调节器的隐式模型跟随鲁棒协调控制器,从而保证飞行器在不确定干扰情况下的闭环系统稳定性.仿真结果表明,本方法所设计的控制器在给定的不确定性范围内具有良好的鲁棒性.%Considering intricate coupling between engine and flight dynamics and complex interaction between flexible and rigid modes, a longitudinal dynamic model for a flexible air-breathing hypersonic vehicle is developed. Unlike conventional aircraft, air-breathing hypersonic vehicles require the propulsion system to be bighly integrated into the airframe.Furthermore, full-scale hypersonic vehicles tend to have very lightweight and flexible structures with low natural frequencies. Therefore, the bending modes are important and affect the amount of airflow entering into the engine, thus influencing the performance of the propulsion system. The equations of motion for the flexible vehicle are derived by using Lagrange ' s equations and capture effect between the pitch and normal accelerations of the vehicle and the structural dynamics. And then, the uneertainties of the longitudinal model are analyzed and a robust coupled controller based on LQR is designed by using implicit model-following method with respect to variations in the vehicle dynamics resulted from fuel consumption. Finally, the simulation results show that the method introduced in this paper is feasible.