Research On Game Guidance Method Based On Fractional Sliding Mode

With the development of aerospace technology,the battlefield environment and the situation of attack and defense are becoming more and more complex.In order to improve the survivability of the battlefield,the target intercepted by missile presents the development trend of high-speed and large maneuver.At the same time,with the development of the aircraft to the direction of intelligence,the penetration maneuver strategy of the target may present diversity,and have the game ability to decide the penetration strategy according to the battlefield situation.This brings a severe challenge to intercept and guidance technology.It is of great strategic significance to study the advanced interception and guidance technology which can deal with high-speed,large maneuvering and strong game targets.Based on the background of interceptor intercepting maneuvering target,this paper studies the estimation method of target maneuvering state,the design of intercepting guidance law with angle constraint and the game guidance method based on target maneuvering estimation.In the process of intercepting and guiding operations,the acquisition of guidance information and the estimation of the target's maneuvering state is a key technology.Because the guidance information needed in the terminal guidance process is usually the higher derivative of the seeker detection information,the differentiator is used to obtain the guidance information.Based on the high-order sliding mode differentiator,a robust precise differentiator for uniform convergence of the initial differential error is designed by introducing the high-order term and designing the switching strategy,which improves the convergence speed of the differentiator and makes it more suitable for the application in the terminal guidance process.After the accurate estimation of guidance information,such as approach velocity,LOS angular velocity and LOS angular acceleration,the target maneuver acceleration can be estimated according to the r elative motion model of missile and target.Finally,the accuracy and uniform convergence of the robust exact differentiator are verified by simulation,and the feasibility of using the differentiator to estimate the maneuvering information of the target i s verified.In order to make the missile give full play to the performance of warhead and achieve the best effect of target damage,the interceptor missile is expected to hav e the ability to attack the target from a specific angle.Therefore,on the premise of meeting the guidance accuracy requirements,the guidance law also needs to meet the attack angle constraints.Fractional sliding mode control theory is an advanced control method developed in recent years.It has the advantages of fractiona l calculus and sliding mode control theory.This paper designs interceptor guidance law based on it.The fractional linear sliding surface and fractional terminal sliding surface are selected respectively,and the corresponding guidance law is designed.Then,Lyapunov stability theory and fractional calculus are used to prove the stability of the guidance law.Finally,the effectiveness of the designed guidance law is verified by simulation.Based on the matrix game theory,the interception penet ration problem is regarded as a two person zero sum game problem.In this paper,the mixed strategy game theory is used to expand the strategies of both sides.The guidance strategy selection problem of interceptor is transformed into a multi parameter opt imization problem with equality constraints.The improved particle swarm optimization algorithm is used to optimize.Finally,the feasibility of the game guidance method is verified by simulation.