Look-Angle-Shaping Guidance Law for Impact Angle and Time Control With Field-of-View Constraint

In this paper, we propose a guidance law that considers the field-of-view (FOV) limitation as well as the impact angle and time constraints. In order to develop the guidance law, we first design a desired look angle that satisfies the FOV limitation and impact angle constraint. Since the desired look angle is designed as a function of a gain that determines the length of the remaining trajectory, the impact time can also be controlled by adjusting the gain. The guidance law is derived so as to stabilize the actual look angle to the desired look angle based on the sliding mode control method. As a result, the proposed guidance law can intercept the stationary target at the desired impact angle and time with satisfying the FOV constraint. The proposed law is expected to achieve more accurate performance in real applications owing to its closed-loop structure with analytic formulation than the existing approach based on open-loop structure using numerical routine. The effectiveness of the proposed guidance law is demonstrated by numerical simulations.