Simple guidance law against highly maneuvering targets

In this paper, a simple guidance law against highly maneuvering targets is suggested. The considered law is based on the well-known proportional navigation, and its main feature is that it yields zero miss distance for any flight time, initial condition or target maneuver. First, a proportional navigation missile-target guidance model is formulated, assuming planar geometry and linear missile dynamics. Then, based on the method of adjoints, the class of guidance loop dynamics rendering zero miss distance is characterized . The relationship between miss distance and the finite time stability of the guidance loop is presented. Design implications of the suggested guidance are outlined. The proposed method is then applied on binomial fifth-order missile dynamics, with the target performing an optimal sinusoidal avoidance maneuver. It is shown that the suggested guidance law requires less missile maneuverability than proportional navigation. It is also shown that when the missile maneuverability is limited, zero miss distance can be obtained provided that the missile has a small maneuverabilityadvantage over the adversary. Furthermore, for the fifth-order missile model, it is illustrated that even when the missile maneuver capability equals the sinusoidal target maneuver amplitude, zero miss distance can be obtained provided that the missile time constant is small enough. a o