Research On The Problems About Midcourse Guidance For Exo-atmospheric Kill Vehicle

As the most realistic ballistic missile defense weapon currently,EKV(Exo-atmospheric Kill Vehicle,EKV)has become the focus of research in the military field all over the world.The flight process of EKV can be divided into initial course,middle course and terminal course.Among the three courses,the midcourse contains the longest span of time and apace and the fiercest confrontation between the offensive and defensive,so it can reflect the merits and shortcomings of the intercept guidance strategy to a great extent.The research on the problems about midcourse guidance mainly includes two aspects: the design of guidance law and the problem of midcourse to terminal handover.The paper addresses the problem of EKV intercepts maneuvering target and conducts a deeply research on the design of midcourse guidance law and the problem of midcourse to terminal handover.The purpose is to optimize the design of midcourse guidance law and improve the effect of the midcourse to terminal handover,the main research contents of the paper are as follows:Firstly,in order to describe the movement of EKV during the flight process,the exo-atmospheric dynamic model of EKV is established based on the relevant parameters collected from papers and documents.This is the foundation for the design of midcourse guidance law.Secondly,the problem of midcourse to terminal handover for the seeker is discussed from two aspects: distance acquisition and angle acquisition.The relationship between the probability of distance acquisition and the distance between the interceptor and the target is derived with knowledge of infrared radiation and infrared detection;The effect of midcourse guidance radar error on the probability of angle acquisition is discussed with the error transitive relationship and the model of the probability of angle acquisition for terminal seeker is established.The main factors affecting the angle acquisition are analyzed through the simulation and the terminal constraint for midcourse guidance law is put forward.Then,according to requirement for angle acquisition of the seeker,the midcourse guidance law is designed based on the variable structure control theory and optimal control theory respectively.The guidance law is realized by the design of the control law based on the pulse working pattern for the attitude and orbit control engine.Finally,for the smooth handover of the trajectory from midcourse guidance to terminal guidance,the concept of transition guidance is introduced to design a new shifted law to realize second-order smooth transition.The time lased for the handover is chosen according to theoretical analysis on the time-lapse of the interceptor and the accumulated heading error.Simulation results show that the shifted law can realize second-order smooth transition of the trajectory actually.