Lyapunov stability based three-dimensional guidance for missiles against maneuvering targets

Two guidance laws using the Lyapunov stability theory are presented in this paper. The first one is an adaptive variable structure guidance, where the switching gain of the variable structure term is determined by an adaptive law. The second one is an augmented proportional navigation guidance, where the terms related to the information on the acceleration, including tangential and normal acceleration, and velocity relative heading angle of the target are grouped into two terms, and are estimated. In the proposed algorithms, not only the target maneuvering, but also the tangential acceleration of the missile, is considered. Simulation results show that no biggish acceleration commands of the missile are required in the final stage of the engagement when using the proposed algorithms.