Research On Terminal Guidance Of Interception For Maneuvering Targets

The technology of the interception for maneuvering targets is one of the focuses on the missile defense system. Focusing on technology requirements of intercepting for maneuvering targets, this dissertation studies the interception modes, the seeker's capture probability, the terminal guidance law and the method to get the maneuver information. The main work and results achieved in this dissertation are summarized as follows:The interception modes of the kinetic defense system are studied. 1) The dynamic model of the interceptor is established and the characteristics of the interception along track and the interception head-on are analyzed; 2) During the terminal guidance, the maximal correct warp ability of two interception modes above is compared, then the overload distribution and the stability of corresponding interception trajectories are discussed; 3) Application problems of the interception along track are analyzed, on this basis, the primary scheme is presented.The method to calculate the seeker's capture probability is proposed and the influencing factors of the probability are analyzed. 1) The capture probability is transformed into probability that the relative position vector between the interceptor and the target locates in a cone, further, the probability is transformed to an integral of a 3-D probability density function in a cone; 2) The calculation method of this integral is researched to obtain the analytic expression of capture probability, and then the expression is simplified with some assumptions; 3) The influence on capture probability by the distance between the interceptor and targets, the seeker's maximum capture distance, the maximum view field angle and the relative position error is respectively discussed.The terminal guidance laws of the interception for maneuvering targets are researched. Moreover, a new method to gain the necessary information for terminal guidance laws is put forward. 1) The interception problem is analyzed in 2-D plane and 3-D space with the differential geometry theory, then the relative motion equations and the terminal guidance laws are deduced; 2) For the application of practical work, the differential geometry guidance law is transformed into an expression based on time domain and application methods of the guidance law are concluded; 3) A spline filter method combined with ARMA innovation models to estimate the maneuvering targets information is proposed and it makes progress on the state estimate precision.It was noticed that, if the relative position error became bigger, the estimate precision of the relative distance between the interceptor and the target would be damaged significantly. Aiming at the above problem, a new means based on the active maneuver of the interceptor, which can advance the estimate precision of the relative distance, is presented. 1) In the beginning of the terminal guidance, while the interceptor maneuvering with specific path, nonlinear filter and differential correction methods are used in the relative distance estimation by the Line-of-Sight angle sequence. The simulation results indicate this method can satisfy requirements of the terminal guidance. 2) Different maneuvers are discussed with observability analysis, according to the results, the maneuver which is vertical to the Line-of-Sight is most effective.Based on the terminal guidance law, the estimate method and the large attitude angle control scheme using the quaternion theory, the integrated 6-DOF simulating system of the terminal guidance is established to analyze two interception modes and to confirm correlative conclusion.Combining with multiple technology fields, such as joint error covariance analysis and time series analysis, this dissertation deeply researches some associated problems in the interception terminal guidance and provides a new thought for studying the similar condition. So, the dissertation has some theoretical significance. The estimate method based on the interceptor active maneuver and the analyses of interception modes are a good reference to the development of the interception for maneuvering targets.