Visibility Augmentation of the Proportional Navigation Guidance

The paper presents a visibility augmentation method for a classical proportional navigation guidance law that helps the pursuer maintaining visual contact with the target, and also allows to recover loss of line-of-sight. The concept of visibility is formally introduced in a modified pursuit-evasion differential game, and it appears in the Lagrangian term of the players’ cost functions. Target visibility is then quantified by means of a visibility function, which adds an augmentation term to the proportional navigation structure. Numerical simulations are used for validation. A further simplification of the guidance law is also presented, using the same arguments that lead to the proportional navigation guidance simplest expression, i.e. considering the players on a nominal collision course. The new simplified law is validated in simulation, and compared against its original expression.