Analysis Of Encounter Conditions For Intercepting A Hypersonic Target

Because of the high velocity of the hypersonic vehicles, it requires hit-to-kill and higher guidance accuracy is a must. But the target’s trajectory form is very complicated, also the near space’s detection environment is complex. All these bring difficulties to detection and tracking during the midcourse guidance process.Limited by the midcourse guidance precision, errors would arise during the handover between midcourse guidance and terminal guidance. These errors will also affect the terminal guidance accuracy. At the same time, during the terminal guidance process, the target may escape interceptor by maneuvering, which will also affect the interception accuracy. It is worth noting that the handover errors and the target maneuver have different impact under different encounter conditions. Therefore, it’s important to analyse the influence on the interception accuracy affected by the handover errors and the target maneuver under different encounter conditions. This article focuses on the study of hypersonic vehicles. In order to achieve a successful interception of the hypersonic target whilst ensuring high accuracy, analysis is needed for encounter conditions in order to design suitable conditions in the handover between midcourse guidance and terminal guidance.First of all, the problem description of the analysis of encounter conditions is given, and interception models are established with the introduction of the intersection angle. The characteristics of the hypersonic target and the difficulties of interception are given. And the problem of the analysis of encounter conditions are described to explain the purpose and significance of the analysis. It is pointed out that the intersection angle is an important parameter to characterise interception geometry. And then the analysis model of interception geometry with the introduction of the intersection angle and the missile-target relative motion model with the introduction of the intersection angle are established respectively. It laid the mathematical foundation for the static analysis and dynamic analysis of encounter conditions.Secondly, the analysis of the encounter conditions with interception geometry and the interceptor’s maneuverablity considered is carried out. Take the target initial position errors, the target velocity prediction error and the target normal maneuver into account, the relations between the maximum allowable target initial position errors, the maximum allowable target velocity deviation, the maximum allowable target normal acceleration and the encounter conditions that can ensure a successful interception are given, and an available intersection angle interval can be get. All these are verified through the simulation.At last, the analysis of the encounter conditions based on Monte Carlo method is carried out. Take the target initial position error, the target radial velocity deviation and the target normal maneuver into account, the simulations of terminal guidance process are given based on Monte Carlo method, and the statistical solutions of the encounter conditions that can meet the requirements are obtained. Through the analysis of special encounter conditions and the comparison of the simulations, it can be concluded that the target radial velocity deviation and the target normal maneuver are the main factors of the analysis of the encounter conditions, while the target initial position error is not.