Design of Guidance Law for Extra-Atmospheric Vehicle Based on Eatimation of Maneuvering Target

Abstract

A modified augmented proportional navigation (MAPN) guidance law is proposed for the extra-atmospheric vehicle by using the adaptive extended Kalman filtering(AEKF) observer to estimate the target maneuver acceleration. The traditional Proportional Navigation (PN) guidance law has higher accuracy, in fact, it has been shown that PN is optimal solution for a stationary target. But for highly maneuvering targets, the accuracy of traditional PNG guidance law may sharply degrade. The Augmented Proportional Navigation (APN) guidance law add an acceleration compensation of the target which is introduced on the basis of PN guidance law to overcome the effect of the acceleration on the guidance accuracy. However, the target maneuver acceleration can not acquired directly with measurement, and a new method to estimate the target maneuver acceleration is established via the adaptive extended Kalman filtering(AEKF) observer in this paper. Mostly, APN law is powerful and useful for maneuvering target intercept, but the observability of the filter becomes depressed and divergent. In order to improve the observability of the system, the MAPNG law is derived by adding the line-of-sight (LOS) information into the APN. Simulation results indicated that, for homing against maneuverable targets, the MAPN guidance law is better than the PN guidance law in the following aspects：the higher guidance accuracy; the lower miss distance and the shorter interception time. It shows that the new guidance law provides significant performance improvements over the commonly used classical proportional navigation law.