Three-dimensional nonlinear H-infinity guidance law

This paper proposes a novel three-dimensional missile guidance law design b ased on nonlinear H-infinity control. The complete nonlinear kinematics of pursuit-evasion motion is considered in the three-dimensional spherical co- ordinates system; neither linearization nor small angle assumption is made here. The nonlinear H-infinity guidance law is expressed in a simple form b y solving the associated Hamilton-Jacobi partial differential inequality an alytically. Unlike adaptive guidance laws, the implement of the proposed ro bust H-infinity guidance law does not require the information of target acc eleration, while ensuring acceptable interceptive performance for arbitrary target with finite acceleration. The resulting pursuit-evasion trajectorie s for both the H-infinity-guided missile and the worst-case target are dete rmined in closed form, and the performance robustness against variations in target acceleration, in engagement condition, and in control loop gain, is verified by numerical simulations. Copyright (C) 2001 John Wiley & Sons, L td.