Research On Active Defense Law Based On Sliding Mode Theory

With the rapid development of missile defense technology,traditional missile penetration measures,including decoy release,multiple warheads,electronic jamming,warhead maneuvering and orbit change,are facing great challenges.In order to improve the penetration ability of high value aircraft,it is very important to study the missile active defense penetration technology.Active defense is a strategy of protecting high-value targets by launching defending missile to intercept the attacking missile.At the same time,in order to further improve the success rate of active defense penetration,it is necessary to restrict the terminal anti-interception angle and time of the defense projectile,while meeting the accurate anti-interception miss amount,so as to meet the coordinated angle and time strike requirements.In this dissertation,the nonlinear relative motion mathematical models of target missile,defending missile and attacking missile interceptor are established.Considering the unknown maneuvering information of the incoming interceptor,the sliding mode control theory is applied to study the cooperative penetration guidance method with terminal space-time constraints in the active defense scenario,which improves the penetration performance of the active defense.The research contents are as follows:(1)The active defense problem with terminal collision angle constraint is investigated,the nonlinear kinematic model is considered,and the guidance information of the attacking missile is unknown.The design of cooperative guidance law with terminal constraint is investigated based on sliding mode control theory.By introducing a globally fast convergent sliding mode approach law and a new type of nonsingular terminal sliding mode surface with fixed time convergence,an active defensive sliding mode guidance law with terminal intercept angle constraint that can converge rapidly is derived.In addition,the unknown maneuvering of interceptor missile is considered as system disturbance,which is estimated by constructing an extended state observer,and the estimated value is fed back to the sliding mode guidance law as compensation.Simulation results show that the active defense sliding mode guidance law with terminal interception angle constraints can improve the speed of sliding mode convergence,and achieve the desired terminal interception angle constraint and zero miss distance constraint.(2)The observability of the state information of the incoming interceptor in the process of active defense penetration is investigated,by increasing the line of sight angle difference between target missile and attacking missile and defending missile and attacking missile,transforming observability into LOS angle constraint.Using sliding mode control theory and optimization theory,considering the unidirectional and bidirectional cooperative cooperation modes between the target missile and the defending missile,the cooperative guidance laws of target missile and defending missile satisfying the observable enhanced detection information are proposed respectively.Under the unidirectional cooperative cooperation mode,the target missile adopts independent maneuver.Based on the double power reaching law and the exponential reaching law with state feedback,the sliding mode guidance law of defending missile is established.In the two-way cooperative mode,base on the oneway cooperative guidance law,the objective function of weighted sum of acceleration between target and defending missile is introduced,and the optimal control theory is applied to deduce the two-way cooperative guidance law.Simulation results show that the proposed cooperative guidance law can guarantee both the good measurement observability and the well defensive guidance accuracy.(3)The three-dimensional active defense problem of multi-defending missiles against attacking missile is investigated,a three-dimensional cooperative penetration guidance law satisfying the space-time constraint of terminal is proposed.Considering the time coordination and the angle coordination of terminal interception between the defending missile and the attacking missile,the corresponding guidance law is derived from the line of sight direction and line of sight normal direction of the defending missile and attacking missile respectively.In the direction of line of sight,the time coordinated guidance law is derived based on the multi-agent consistency theory,so that each defending missile can hit the attacking missile at the same time.In the normal direction of the line of sight,based on the finite time sliding mode control method,a space cooperative guidance law satisfying the terminal interception angle constraint is derived.In addition,the state observer is used to estimate the acceleration disturbance of the attacking missile,which reduces the chattering phenomenon of the three-dimensional cooperative guidance law.The simulation results show that the proposed three-dimensional cooperative guidance law can ensure that each defending missile can hit the target missile at the same time with different terminal intercept angles.