Finite-Time Impact Time Guidance using Deviated Pursuit against Maneuvering Targets

This paper proposes several nonlinear impact time control guidance strategies against maneuvering targets, based on Lyapunov and sliding mode control theories. These strategies correspond to different quanta of information available to the interceptor, about the target's maneuver. The use of deviated pursuit paradigm in the guidance design enables the use of exact time-to-go expression for intercepting moving but non-maneuvering targets, without any small-angle approximations in heading angles. In deriving the guidance commands, the time-to-go is estimated by assuming a non-maneuvering target at each instant. Due to the inherent robustness of the proposed strategies, maneuvering targets can also be successfully intercepted at desired impact times, despite this assumption. Numerical simulations are presented to validate the efficacy of proposed guidance strategies for different initial engagement geometries and levels/types of target maneuvers.