Homing Missile Guidance Studies: Observability, Adaptability, and the Linear Exponential Gaussian Guidance Law

摘要

This study is divided into two parts. First, the observability of the system states is considered when angle information is available. The pseudolinear measurements are used to determine global observability for this nonlinear estimation problem. An observer is constructed by defining a Lyapunov function of the estimation errors. Numerical experiments are used to determine the gains necessary to accurately determine all the states within the time of the engagement. If measurement noise is present, the filter is biased. Techniques of reducing the effect of the bias are explored. The second phase considers the combination of the linear exponential Gaussian (LEG) guidance law with an extended Kalman filter (EKF). The measurement variance of the EKF is estimated on-line. The error variance generated by the EKF is used in the LEG guidance law adaptively, changing its gains. This system is tested in a six-degree-of-freedom simulation of a bank-to-turn missile. (Author)