Time-to-Go Inversion Guidance for Field-of-View Limited Impact Angle and Time Control

This paper presents a time-to-go inversion guidance approach that achieves the simultaneous control of impact time and angle under field-of-view (FOV) constraints. First, a twodimensional (2D) FOV-limited impact angle control guidance (IACG) law is inversely derived from an explicit time-to-go function. Next, the proposed 2D FOV-limited IACG law is extended to the three-dimensional (3D) scenario by decoupling the engagement geometry into flight and impact planes. The unique advantage of the 2D and 3D FOV-limited IACG laws is that they can offer exact time-to-go predictions in closedform. Using this property, FOV-limited impact time and angle control guidance (ITACG) laws can be easily developed for both 2D and 3D scenarios. Compared with similar studies, the proposed ITACG laws based on the time-to-go inversion guidance approach do not require any linearized approximations or numerical iterations, and thus possess less control effort, reduced computational complexity, and improved stability under large impact-angle errors. Finally, the effectiveness and superiority of the proposed guidance laws are validated through extensive numerical simulations.