Composite Guidance for Impact Time Control Under Physical Constraints

This article presents a composite guidance law comprising a three-stage proportional navigation (PN) structure for the simultaneous arrival of multiple missiles. Motivated by the fact that the selection of the navigation constant considerably influences the trajectory shape, the proposed composite law is designed to have different navigation constants at each stage to achieve the desired impact time. The three stages of the proposed law are configured to sequentially increase, maintain, and decrease the magnitude of the look angle by switching only the navigation constant, through which the seeker’s field-of-view constraint, which is mainly determined by the look angle, can be satisfied without additional considerations. Furthermore, the simple PN-based structure of the proposed law makes it possible to obtain an exact closed-loop solution, providing various useful information for practical implementation, such as the expected trajectory, required guidance command, and range of achievable impact time. In addition, the relevant investigations based on the theoretical analysis as well as the demonstration results obtained through the numerical simulation are presented herein.