Research Of Multi-Interceptor Cooperative Guidance Law With Line-of-Sight Angle Constraint

With the development of missile technology,the penetration ability of missile is increasing.So it is more difficult to accomplish the interception mission by single missile.Multi-missile cooperative combat has the characteristics of large kill radius and high success rate of interception.And it is an effective means to implement saturation attack and interception.To improve the guidance accuracy of intercepting the unknown maneuvering target,the observer is designed to estimate target’s motion information.The problem of multi-missile cooperative interception with the desired Line-of-Sight(LOS)angle is studied in the thesis,and the main work is as follows:(1)Aiming at the problem that it is difficult to accurately measure the target’s maneuvering information,the target motion is regarded as the external disturbance of the guidance system.First,a fixed-time sliding mode disturbance observer(FTSMDO)is designed to estimate the disturbance,and its fast convergence performance is analyzed.Then,the effectiveness of the observers is verified by simulation.(2)To solve the problem of multi-missile intercepting target with desired LOS angle,this paper designs a three-dimensional(3D)cooperative guidance law which satisfies the constraints of miss distance and LOS angle,taking the estimated time-to-go as the coordination variable.First,the guidance law on the LOS direction is designed,which can guarantee fixed time consensus of missiles’ time-to-go.Next,in the elevation direction and azimuth direction of LOS,based on the sliding mode control theory,the guidance commands are proposed respectively to guarantee LOS angles converge to desired values and LOS angular rates converge to zero in fixed time.Finally,the effectiveness of the 3D cooperative guidance law is demonstrated by simulation result.(3)To avoid the introduced error of time-to-go,chattering and singularity,taking the range-to-go and relative velocity as the coordination variables.Based on the integral sliding mode,a 3D cooperative guidance law with LOS angle constraint is designed.It is proved that the cooperative guidance law can ensure that the range-to-go and relative velocity of all missiles converge to consistent respectively,and the LOS angle converge to its desired value within fixed time.The simulation results show that the 3D integral sliding mode cooperative guidance law can be used to intercept different maneuvering targets,and the upper bound of the convergence time is independent of the initial states.