Research On Guidance Law For Intercepting High Maneuverability Targets

With the rapid development of aerospace weapons,the response time of air defense missiles in intercepting high maneuverability targets in the air is constantly shortened,which increases the difficulty of interception.How to achieve precise interception of highly maneuverable targets is of great research value.Aiming at the precise guidance problem of air defense missile intercepting air high maneuverability target aircraft,this thesis studies the guidance law of the air defense missile guidance system,estimate the acceleration of highly maneuverability targets with a speed exceeding Mach 5 in the vicinity of space,and design a three-dimensional terminal guidance law that converges in a finite time period,taking into account the dynamic time delay characteristics of the autopilot.Firstly,the coordinate systems needed to intercept high maneuverable targets are defined,and the rotation matrices between the coordinate systems,the six-degree-of-freedom mathematical model of air defense missile and the corresponding structural parameters,the mathematical model of missile aerodynamic force and aerodynamic torque are given,and threedimensional missile-target relative motion equations in line-of-sight coordinate system are established.Secondly,aiming at the problem that the maneuvering acceleration of the target cannot be accurately obtained when intercepting the highly maneuverability target,based on the "current" statistical CS model,this thesis studies an EKF for estimating and obtaining the relevant maneuvering information of the target with a single model.Thirdly,aiming at the precise guidance problem of missiles intercepting high maneuverability targets,from the perspective of guidance law,based on variable structure control theory and the finite time convergence control theory,this thesis studies a sliding mode terminal guidance law with limited time convergence considering the line-of-sight angle constraint.On this basis,the dynamic characteristics of the missile autopilot are taken into account,and the sliding mode terminal guidance law which converges in finite time and considers the dynamic time delay characteristics of autopilot is studied.Finally,in order to verify the feasibility of the EKF used to estimate the maneuvering information of the target and the sliding mode terminal guidance law with finite time convergence considering the dynamic time delay characteristics of the autopilot,this thesis has carried out many Monte Carlo simulation experiments on the interception process,and the hitting accuracy is over 95% after many simulations,which proves that the designed EKF and terminal guidance law can effectively intercept the target.