Nonlinear Cooperative Strategy for Active Aircraft Defense with Exact-time Convergence

This paper addresses an active aircraft Defense problem wherein an aircraft is under attack by an external in-terceptor, and a defender is launched to neutralize the attacker. We develop a nonlinear guidance law that guarantees that the defender intercepts the attacker before it reaches the vicinity of the target. The guidance strategy is derived using the concept of line-of-sight guidance, where the defender is allowed to move toward the attacker while maintaining his position between the target and the attacker. We show that knowing the attacker's maximum acceleration capability is sufficient to guarantee the successful interception of the attacking interceptor. Nevertheless, the proposed guidance strategy is derived within a nonlinear engagement framework, which elucidates its applicability for broader operating conditions, unlike the methods where the linearized dynamics were considered. Finally, we demonstrate the merits and robust performance of the proposed guidance strategies with various engagement scenarios.