Servo Elastic Analysis On Missle With Lateral Jets And Aerodynamics Control

This thesis is focused on the influence of elastic vibration on the attitude control system of the slender endo-atmospheric airdefence missiles with lateral jets and aerodynamics control. The main researches are as follows.Firstly, the rigid model of attitude motion of airdefence missile is established. Consider the attitude control mode of the lateral jets,based on the analysis of the missile's force and torque, the motion equations were constructed. And then decompose it into two parts, that the vertical movement and lateral movement, under certain assumptions. We can obtain the missile's linear motion model in pitch plane by adopted the small perturbation theory and the freezen coefficients method.Secondly, Missile is a slender body, with flexible features. So consider the missile as an elastic body, the flexible missile is idealized as a uniform free beam. The vibration analysis was carried out by using Euler beam model. The natural frequencies and natural modes were derived by modal analysis, and generalized coordinates equations, which is the representation of elastic were acquired. After that, the vibration response caused by lateral jets is analyzed, and a number of preliminary simulations about the elastic deformation is conducted.Thirdly, the formation principle of servo elasticity problem of missile was explained combining with the concept of aeroservoelasticity. And the attitude motion model of the flexible missile was derived. Take pitch plane motion as an example, a controller of the rigid body is designed, then considering the elastic vibration, A number of simulations in Simulink environment are conducted. Simulation results show that the elastic vibration caused by lateral jets will also affect the stability of the attitude control system. Then give some preventive and control measures, and design a filter, which can restrain elastic vibration effectively from the simulation results.