Target Defense against Sequentially Arriving Intruders

TL;DR

This paper studies a sequential target defense game where a defender aims to capture multiple intruders arriving randomly around a target, analyzing strategies and equilibrium outcomes under different information scenarios.

Contribution

It introduces a novel sequential intruder defense model with equilibrium strategies and quantifies capture probabilities for multiple intruders.

Findings

Derived equilibrium strategies for both players.

Quantified capture percentages for finite and infinite sequences.

Analyzed strategies under partial and full information scenarios.

Abstract

We consider a variant of the target defense problem where a single defender is tasked to capture a sequence of incoming intruders. The intruders' objective is to breach the target boundary without being captured by the defender. As soon as the current intruder breaches the target or gets captured by the defender, the next intruder appears at a random location on a fixed circle surrounding the target. Therefore, the defender's final location at the end of the current game becomes its initial location for the next game. Thus, the players pick strategies that are advantageous for the current as well as for the future games. Depending on the information available to the players, each game is divided into two phases: partial information and full information phase. Under some assumptions on the sensing and speed capabilities, we analyze the agents' strategies in both phases. We derive equilibrium strategies for both the players to optimize the capture percentage using the notions of engagement surface and capture circle. We quantify the percentage of capture for both finite and infinite sequences of incoming intruders.