Research On Guidance Law With Multiple Constraints For Intercepting Maneuvering Target

With the development of aerospace technology,the speed,maneuverability and electronic countermeasures of the target are constantly improved,which requires the defense system to have better performance.The traditional terminal guidance law constrained by miss distance is facing great challenges.In the system confrontation environment,the missile is required not only to have high interception performance,but also to have the ability of cooperative operation.In this paper,the guidance law with multiple constraints for intercepting high-speed maneuvering targets are studied considering the missile space attack orientation constraint,the unknown maneuvering of the target,the acceleration saturation constraint and the impact time constraint.The main research contents are as follows:Firstly,the convergence process of the line-of-sight angle is studied based on prescribed performance control method.A novel error transformed function is designed and a special sliding mode surface is proposed based on tanh boundedness function,and the two/three-dimensional performance constraint guidance law is designed to simultaneously constrain the convergence time,the maximum overshoot and the steady-state error.The simulation results are compared under different missile models and target maneuvers.Secondly,a double integral auxiliary system is designed to compensate the influence of acceleration saturation on the system state,and the three-dimensional anti-saturation performance constraint guidance law based on "state compensation" and "improved constraint function" are designed to solve the contradiction problem between performance constrained control and saturation control.The effectiveness and superiority of the proposed guidance law are verified by simulation comparison in special scenarios such as controller saturation caused by sudden disturbance.Thirdly,the distributed and leader-follower fixed-time convergence cooperative guidance law with undirected/directed connectivity of the communication topology are designed based the consistency theory,terminal sliding mode control and nonlinear disturbance observer.A fixed-time convergence time-coordinated guidance law is designed in the line-of-sight direction based on the instantaneous time-to-go and the coordination variables,respectively.By designing a improved performance constraint function including the steady-state convergence time,the line-of-sight angle prescribed performance constraint guidance law is designed in the normal direction.Simulation results in different scenarios verify the superiority of the proposed guidance law.Finally,considering the cooperative guidance system under normal overload control of missile,a cooperative proportional guidance law with terminal angle constraint is designed based on time-varying navigation ratio and the angle feedback bias term.Furthermore,considering the problem of impact time control for intercepting maneuvering target,the impact time control guidance law is proposed based on sliding mode control.By switching proportional guidance in the later stage,the impact time of each missile can be adjusted to the maximum extent on the premise of ensuring the guidance accuracy,so as to complete the sequential or simultaneous attack on the target.