Three-Dimensional Nonsingular Impact Time Guidance With Limited Field-of-View

This article proposes barrier Lyapunov function-based guidance strategies to achieve target interception, by a seeker-equipped interceptor having a limited field-of-view (FOV), at a prespecified impact time. A novel approach to respect the FOV constraint, using the conditions on time-to-go of the engagement, is first proposed. Guidance commands are then derived to steer the course of the interceptor in a way so as to adhere to the necessary conditions. Guidance strategy is first derived for 3-D engagements, and then, the same for planar scenarios is presented as a special case. The set of achievable impact times for given initial conditions, while satisfying FOV constraints, is first obtained, and then, a way to expand the achievable range of impact time is suggested using a two-stage approach. The behavior of lead angle is analyzed, and it is shown that guidance commands remain nonsingular and converge to zero near interception. Simulations are shown to validate the efficacy of proposed methods for various initial engagement geometries.