Reserch On Time Convergence Cooperative Guidence Law For Mutiple Interceptor

With the development of military technology,the maneuverability of aircraft is increasingly improved,which poses a great threat to the modern defense system.Under this circumstance,it is difficult to meet the operational needs with a single interceptor.The cooperative operation with multiple interceptors can effectively compensate for the shortcomings of a single interceptor.Therefore,the multi-interceptor cooperative guidance has attracted wide attention from scholars at home and abroad.In addition,in actual combat,targets often adopt maneuver penetration strategies to further increase the interception difficulty of the defense system.Thus,higher requirements are put forward for the design of cooperative guidance laws for multi-interceptor missiles.In this paper,the interception of a single high-value maneuvering target by multi-interceptor missiles in the terminal guidance phase is studied.The objective is to improve the convergence characteristics of the cooperative guidance law.The design of the multi-interceptor missile cooperative guidance law is researched from perspectives of the finite-time convergence cooperative guidance law,the fixed-time convergence cooperative guidance law,the predefined-time convergence cooperative guidance law,and the appointed-time convergence cooperative guidance law with attack angle constraints and attack time constraints.The main research contents are as follows:First,for multi-interceptor missiles intercepting a single maneuvering target,a finite-time/fixed-time convergence cooperative guidance law with attack angle constraints and attack time constraints is designed.A two-dimensional mathematical model of a cooperative guidance system with attack angle and attack time constraints is established.In order to realize that all interceptors simultaneously hit the target at the desired angle under the undirected topology,a finite-time convergence cooperative guidance law is proposed based on the finite-time multi-agent consensus algorithm and the non-singular terminal sliding mode control algorithm.Through the inhomogeneous disturbance observer,the external interference caused by the target maneuver in real time is estimated and compensated to the guidance system.In order to further improve the guidance performance and the convergence speed of the guidance system,a fixed-time convergence cooperative guidance law with attack angle constraints and attack time constraints is proposed.Based on the fixed-time convergence consensus algorithm,a cooperative guidance law in the direction of line-of-sight(LOS)is designed to ensure that all interceptors hit the target at the same time.In order to further ensure the fast convergence of the LOS angle and the LOS angular rate,a fixed-time convergence cooperative guidance law in the normal direction of the LOS is designed based on a fixed-time convergence disturbance observer and adaptive sliding mode control.It improves the guidance accuracy and anti-interference ability of the cooperative guidance law.Secondly,considering that the duration of terminal guidance during the interception of maneuvering targets is very short,the designed guidance law needs to have fast convergence characteristics,and the convergence time of the guidance law also needs to have a predefined upper limit to ensure that the system stabilizes before hitting the target.To solve the above problems,this paper proposes a predefined-time convergence cooperative guidance law with attack angle constraints and attack time constraints.The proposed cooperative guidance law uses convergence time as an adjustable parameter to make the upper bound of the convergence time controllable so that the cooperative guidance law can meet the design requirements for convergence time.In the direction of the LOS,this paper proposes a cooperative guidance law based on a predefined-time consensus algorithm,so as to ensure that the remaining flight time of all missiles achieves consensus within the predefined time.In the normal of the LOS direction,based on the fixed-time disturbance observer and the predefined-time convergence theory,the cooperative guidance law for the predefined-time convergence in the normal of the LOS direction is designed.It ensures that the LOS angular rate of all missiles can converge to the neighborhood of the origin and the LOS angle can converge to the desired LOS angle within a predefined time,which effectively improves the convergence speed and robustness of the system.Finally,a fast convergence rate of the cooperative guidance system will lead to guidance performance degradation or system instability.In order to further improve the reliability and stability of the multi-missile cooperative guidance system,an appointed-time convergence cooperative guidance law is developed.It makes the multi-interceptor cooperative guidance system stabilize at a given moment under external disturbances,and weakens the influence of the uncertainty of the convergence time on the guidance performance.Based on a connected undirected graph for the communication topology,the appointed-time convergence cooperative guidance law in the LOS direction is studied to ensure that the remaining flight time of all missiles reaches an agreement at the appointed time.In order to estimate the target maneuver in real time,this paper adopts an appointed-time convergence disturbance observer and combines the backstepping method,integral sliding mode control,and appointed-time convergence theory to design an appointed-time convergence cooperative guidance law for multi-interceptor missiles in the normal direction of the LOS.It ensures that multi-interceptor missiles have good guidance performance in the cooperative interception process.