Research On The Time Convergence Guidance Method For The Intercept Missile

With the rapid development of modern guidance and control technology,precision guided weapons are becoming more and more threatening to national defense and security.Therefore,the interception performance of defense missile is required to be higher.The incoming enemy target evades interception by maneuvering in the termianl guidance phase.In order to ensure the successful interception against target,the defense missile should be capable of intercepting maneuvering targets.As the core of defense missile guidance system,the guidance technology directly affects the operational effectiveness of defense missile.The terminal guidance time is usually short for defense missile intercepting maneuvering target.Based on the finite/fixed time control theory,it is great theoretical and practical significance to design the interception guidance law which can ensure the rapid stability of missile guidance system.The research background of this paper is defense missile intercepting maneuvering target.The interception guidance methods are studied for defense missile.To improve the guidance precision and operational effectiveness of defense missile,two kinds of interception guidance methods are studied which are respectively that a single missile intercepts a target with the desired attack angle and multiple missiles cooperatively intercept a target.The main contributions of this paper are summarized as follows:The capability requirement of a single missile hitting a target at the desired attack angle is proposed to maximize the operational effectiveness of intercepting maneuvering target with a single missile.Based on the finite time control theory,the finite time guidance law with terminal attack angle constraint is designed for the guidance problem of a single missile intercepting maneuvering target at the desired attack angle.Firstly,the relative kinematics equation between missile and target is derived according to the plane geometry relation of missile intercepting maneuvering target.Then,the two-dimensional guidance system is established with the terminal attack angle constraint.The two-order sliding mode guidance law with finite time convergence is designed which is based on fast non-singular terminal sliding mode control theory and super-twisting control theory.Furthermore,based on the designed two-order sliding mode guidance law and combined with adaptive control theory,the adaptive two-order sliding mode guidance law with finite time convergence is designed for the unknown upper boundary value of the first derivative of guidance system disturbance.Finally,the guidance performance of the missile under the two finite time guidance laws is verified by simulation.The initial launch conditions will affect the stability time of missile guidance system,and thus the guidance performance will be affected.Based on the fixed time control theory,the fixed time guidance law considering the terminal attack angle constraint is designed to ensure the stability time of missile guidance system does not depend on the initial launch conditions of missile.Firstly,based on the traditional two-dimensional guidance system of missile intercepting maneuvering target,the improved two-dimensional guidance system with terminal attack angle constraint is established for the condition that guidance command can not adjust the system states under certain conditions.Then,the sliding mode guidance law with fixed time convergence is designed which is based on fixed-time fast non-singular terminal sliding mode control theory and fixed-time disturbance observer.Furthermore,based on adaptive control theory and fixed-time non-singular terminal sliding mode control theory,the adaptive sliding mode guidance law with fixed time convergence is designed for the unknown boundary value of guidance system disturbance.Finally,under the two fixed time guidance laws,the missile can ensure the guidance system reach stability in a fixed time.The guidance performance of the missile is verified by simulation.The design of two-dimensional guidance law ignores the coupled dynamics that is in the three-dimensional missile-target relative motion equation.Based on finite/fixed time control theory,the three-dimensional guidance laws with terminal atttack angle constraints are designed to make the designed guidance law easier for practical engineering application.Firstly,the relative kinematics equation between missile and target is derived according to the three-dimensional geometry relation of missile intercepting maneuvering target.Then,the three-dimensional coupled guidance system with terminal attack angle constraints is established which considers the guidance purpose of intercepting maneuvering target with desired terminal attack angle.Based on fast non-singular terminal sliding mode control theory and adaptive control theory,the three-dimensional sliding mode guidance law with finite time convergence is designed to ensure the fast stability of guidance system.Furthermore,the three-dimensional guidance law with fixed time convergence is designed which is based on fixed time fast non-singular terminal sliding mode control theory.Finally,under the designed two guidance laws,the missile can ensure the guidance system reach stability in a finite/fixed time.The guidance performance of the missile is verified by simulation.Considering the limited operational capability of a single missile,the missile needs to have the ability to cooperate with other missiles to intercept the target.Based on multi-agent consistency theory,the cooperative guidance law without radial velocity measurement and the cooperative guidance law under constrained communication are designed for the cooperation and communication problems of multiple missiles intercepting a single maneuvering target.Firstly,the three-dimensional cooperative guidance system is established for intercepting maneuvering target by multiple missiles.Based on system homogeneity theory,fixed time disturbance observer and adaptive control theory,the fixed time cooperative guidance law is designed without the radial velocity measurement between missile and target.Then,the two-dimensional cooperative guidance system is established for intercepting maneuvering target by multiple missiles.The cooperative guidance law considering communication delay and switching communication is designed which is based on linear matrix inequality theory,finite time disturbance observer and adaptive control theory.Finally,under the designed two cooperative guidance laws,multiple missiles can intercept a single maneuvering target simultaneously.The guidance performance of each missile is verified by simulation.