Research On Terminal Guidance Law For Countermeasures Based On Differential Game Theory

Under the condition of high-tech war,the development trend of high maneuverability,intelligence and clustering is presented for both sides of the offensive and defensive confrontation.In the future high dynamic confrontation environment,both sides of the confrontation will face opponents with stronger maneuverability,higher intelligence level and larger cluster size.For the attacker,it is necessary to improve the interception ability against the target.On the one hand,it can improve the hitting accuracy and single-shot interception probability by improving the navigation and guidance control system.On the other hand,a many-to-one way can be adopted to improve the damage probability of the target through cooperative interception.On the contrary,for the defense side,on the one hand,it can increase the attacker's miss probability by improving the early warning ability by releasing bait and interference or implementing optimal evasion maneuver.On the other hand,active defense can be adopted,such as launching defensive missiles,carrying out active interception on the attacker and maneuvering at the same time,so as to achieve the purpose of anti-interception through active cooperation.In this thesis,the terminal guidance method in offensive and defensive countermeasures is taken as the main line of research.Based on the theory of differential game,the research and analysis are mainly carried out around the active defense guidance law,cooperative guidance law and integrated guidance/estimation design method.The main research contents and achievements of the thesis are as follows:Aiming at the typical pursuit-evasion problem,the optimal evasion maneuver strategy of the target vehicle under the condition that the interceptor missile adopts the linear optimal guidance law is studied.If the interceptor missile guidance law is known,the optimal evasion maneuver strategy is deduced in the pursuit problem in the atmosphere.The typical linear guidance laws are analyzed on the condition of complete information and incomplete information pursuit-evasion scene,the optimal evasion maneuver strategy is verified.In order to improve the interception efficiency,the differential game guidance law with terminal collision angle constraint is studied.Considering the dynamic characteristics of the missile body,the linear quadratic optimal guidance law and the linear quadratic differential game guidance law are designed respectively by introducing the terminal collision angle constraint,which can realize the ability of rounding up and intercepting the target from different directions and angles.Considering the scenario of multiple interceptor missiles,a cooperative differential game guidance law with dynamic characteristics is proposed to improve the adaptability of the guidance system to the changes of target maneuvering overload.To effectively improve the survivability of the target spacecraft in the face of high-performance attack missile,the target-defender-attacker problem has been studied based on differential game theory to design the active defense guidance law.The target and the defender can maneuver cooperative against attack missile interception.It can reduce the overload requirements of the defender.An active defense guidance law with terminal collision angle constraint is proposed,which can realize multi-angle interception of defensive missile against attacker,enhance attack capability of defender,and improve survivability of target.The problem of target state estimation of the interceptor missile using passive detection equipment such as infrared is studied.And the observability of relative distance is worth studying under the condition of passive measurement.In the terminal guidance,the relative distance observability is poor because the collision triangle has been formed between the missile and the target.The traditional guidance law usually inhibits the rotation of line-of-sight angle.For exoatmospheric interception problem of maneuvering targets,the integrated estimation guidance method was designed.An observability enhancement differential game laws has been puts forward by using the nonlinear filter and the singular regional characteristics in the differential game guidance law,it can improve the observability under the passive detection.In active defense,using multiple defenders to intercept one attacker,on the one hand,can improve the probability of attacker interception,on the other hand,control the flight trajectory by introducing different collision angles of the defenders.It can increase the relative angle of view and improve the observability of the attacker.Based on the theory of differential game,a cooperative guidance law with relative collision angle constraints is designed,and a cooperative state estimator is designed by using nonlinear filtering.It can effectively improve the survivability of target aircraft by taking full advantage of cooperative active defense and cooperative detection.The research of this paper consider the design of guidance laws in a variety of scenarios,involved in active defense guidance law,cooperative guidance law and integrated guidance/estimated design problems.Several terminal guidance methods were studied,and a variety of guidance for different scenarios are put forward.It has a certain theoretical significance and practical value in engineering.