Escaping the Double Threat: Modified PPN Law and Evasion Strategy for 2-on-1 Pursuit

Recent research on guidance strategies has seen an increased focus on cooperative guidance strategies for the three body engagement scenario, where the target aircraft and its defender interceptor cooperate to thwart the threat posed by an attacking interceptor (also called the pursuer). However, with an increased number of pursuers, such strategies are unlikely to be effective since even after the defender neutralizes one of the pursuers, the remaining pursuers can still intercept the target aircraft. This leads to a demand for the development of defensive guidance strategies for scenarios where non-cooperating pursuers pursue a target when the target does not have enough defenders to nullify the threat posed by each pursuer individually. This paper first proposes a variant of the pure proportional navigation (PPN) guidance law that allows a pursuer to successfully intercept its target while evading a defender released by the target. Subsequently, we show that when two such non-cooperating pursuers employ the aforesaid strategy against a target with a solitary defender, the pursuers' strategy fail since they are lured into trajectories by the cooperating aircraft-defender team that leads to their mutual collision. Simulations are performed to validate the claims of the proposed guidance strategy.