스트랩다운 탐색기 유도탄의 PNG에 적용되는 LOS rate 유도

Abstract

This paper presents the method of a LOS (line-of-sight) rate derivation from image plane values of the output of the strapdown seeker and coordinate frame transformation. The LOS rate is applied to calculate PNG (proportional navigation guidance) laws for missile. Gimbaled seekers may provide LOS directly for guidance system. However, the strapdown seekers provide LOS angles from body to target in a body frame. For PNG the LOS angles need to be changed to their rates in the inertial frame. The proposed derivation of LOS rate is verified by simple but realistic simulation of a short range ground to ground missile. The homing guidance using the LOS rate results in 10 meter miss-distance accuracy. Even though the result is similar to the one of gimbaled seeker, the strapdown seeker missile has significant cost savings advantage with eliminating the gimbals as well as eliminating frictional cross coupling between pitch and yaw tracking channels.