Study On Terminal Guidance And Control For Intercepting Maneuvering Targets In Upper Atmospheric Layer

At present,the accurate technology of intercepting ballistic targets has been developed,however further researches are required to intercept maneuvering targets,especially the near space hypersonic vehicle which has obtained rapid developments in recent years.The vehicle brings great threats to the existing air and missile defense systems(AMDSs).Because terminal guidance and control technology is one of the most key ones in AMDS to realize kinetic kill,the research is carried out in this dissertation on terminal guidance and control for intercepting maneuvering targets.In terms of the terminal course of missile intercepting targets,the model of relative motion between missile and target is established and the motional characteristic is analyzed emphatically.By means of the improvement of typical proportional navigation,the analytical relationship between line of sight(LOS)rate and relative distance is also achieved under the condition of target maneuvering.Finally,the possible engagement patterns are presented in the process of intercepting targets.This chapter is the basis of subsequent researches.The method of terminal guidance based on the differential geometric theory is studied.Firstly,the differential geometric model of terminal interception is established.No limitations are made on the motion states of missile and target and the derivation of differential geometric guidance law(DGGL)is directly performed with the help of the mutual relation among the three axial unit vectors of LOS rotation coordinate system,which is intended to solve the problem that the original DGGL is limited to the situation that the ratio of target to missile is constant and less than 1.The derivation is simplified and has more explicit physical significances.Then,the new DGGL is obtained,which is theoretically suitable for all engagement scenarios.The initial capture condition is analyzed.Finally,the efficiency of the extended DGGL is validated through interception simulations of pursuing and head-on engagements.The approaches to acquire information of relative motion under the condition of passive measurement are discussed.In order to solve this problem,the state equation representing relative motion and the passive measurement equation are established.The adaptive extended Kalman filtering(AEKF)and two-step filtering(ATSF)are used to estimate the system state,and then the guidance command is calculated through making use of the estimated values.The simulation results demonstrate that the precision o f guidance information provided by the two filters both can satisfy the requirement of terminal guidance precision.In addition,the performance of ATSF is better than AEKF.The method of terminal guidance and control applied to kinetic kill vehicles(KKVs)adopting the side window detection is researched.The true proportional navigation and theory of sliding mode are employed to guide KKV and control its attitude,respectively.By means of designing the switch control law of orbit thrusters and resorting to the pulse-width and pulse-frequency modulator,the continuous control commands are transformed into the ones of starting up or shutting down thrusters.The simulations indicate that the proposed method of guidance and control is able to meet the constraints of side window and realize the kinetic kill when it is applied to intercept high-speed maneuvering targets in the terminal course.This dissertation's studies are capable of providing theoretical bases for developing the terminal guidance and control technology of intercepting maneuvering targets and technical supports for the development of our country's next generation of AMDS.