Three-Dimensional Field of View Constraint Impact Time Guidance Law for Varying-Speed Missile

This paper proposes a three-dimensional (3D) field-of-view (FOV) constraint impact time control guidance (ITCG) law for intercepting non-maneuvering targets under aerodynamic and gravitational effects. First, based on a novel impact time error, a line-of-sight (LOS) rotation rate profile is designed to achieve both zero miss distance and impact time constraints. Then, a feedback guidance law is developed by using fixed-time control technique to ensure the tracking error converges to zero within a fixed time. Finally, the proposed ITCG law is applied to intercept non-maneuvering targets through the predicted interception point (PIP) technique. Unlike existing studies, this proposed ITCG law converts the ITCG problem into a stabilization tracking control problem, enabling precise impact time control without using model decoupling or linearization. Moreover, the FOV constraint is satisfied through proper guidance gain k selection without introducing switching logic or auxiliary functions, which significantly enhances engineering applicability. Finally, extensive numerical simulations have validated the effectiveness of the proposed ITCG law.