Practical guidance considering filtering performance for attacking maneuvering targets

For missiles with passive seeker, they are usually little observable because only the line of sight (LOS) information is obtained without distance information. It's difficult to take both aspects that the observability of filtering model and hit accuracy of the maneuvering target, into account at the same time. For this problem, the motion tracking sliding mode guidance law is adopted in this paper, and the specified form of LOS rate and the method to determine value of its parameters are given. Firstly, the relative motion model and the conclusion that it is necessary to reduce the LOS rate to improve the accuracy of the guidance, are given. Then, features of standard PNG (Proportional Navigation Guidance), MAPNG (Modified Augmented Proportional Navigation Guidance) and MTSMG (Motion Tracking Sliding Mode Guidance) are analyzed. With regard to MTSMG, a LOS rate curve form is designed, which can both improve the observability and hit accuracy. Finally, the relationship between the upper limit of LOS rate and the relative distance is deduced, and the method to select parameters is given in order to determine the final value of the expected LOS rate. Simulation results show that, compared with the standard PNG and MAPNG method, the hit accuracy of improve method in is paper is higher and the filtering performance is good.