Multiplayer Reach-Avoid Differential Games in 3D Space Inspired by Harris' Hawks' Cooperative Hunting Tactics

This paper investigates a multiplayer reach-avoid differential game in 3-dimensional (3D) space, which involves multiple pursuers, multiple evaders, and a designated target region. The evaders aim to reach the target region, while the pursuers attempt to guard the target region by capturing the evaders. This class of research holds significant practical value. However, the complexity of the problem escalates substantially with the growing number of players, rendering its solution extremely challenging. In this paper, the multiplayer game is divided into many subgames considering the cooperation among pursuers, reducing the computational burden, and obtaining numerically tractable strategies for players. First, the Apollonius sphere, a fundamental geometric tool for analyzing the 3D differential game, is formulated, and its properties are proved. Based on this, the optimal interception point for the pursuer to capture the evader is derived and the winning conditions for the pursuer and evader are established. Then, based on the Apollonius sphere, the optimal state feedback strategies of players are designed, and simultaneously, the optimal one-to-one pairings are obtained. Meanwhile, the Value function of the multiplayer reach-avoid differential game is explicitly given and is proved to satisfy Hamilton-Jacobi-Isaacs (HJI) equation. Moreover, the matching algorithm for the case with pursuers outnumbered evaders is provided through constructing a weighted bipartite graph, and the cooperative tactics for multiple pursuers are proposed, inspired by the Harris' Hawks intelligent cooperative hunting tactics. Finally, numerical simulations are conducted to illustrate the effectiveness of the theoretical results for both cases where the number of adversary players is equal and unequal between the 2 groups.

War Game between Two Matched Fleets with Goal Options and Tactical Optimization

A war game between two matched fleets of equal size and capability is designed and simulated in this work. Each fleet is composed of a carrier vessel (CV), a guided missile cruiser (CG), and two guided-missile destroyers (DDGs). Each vessel is equipped with specific weapons, including fighters, missiles, and close-in weapon system (CIWS), to carry out tactical operations. The maneuverability, maximum flying distance, and kill probability of different weapons are specified. Three goal options, a defense option and two more aggressive ones, are available to each fleet. A particle-pair swarm optimization (P2SO) algorithm is proposed to optimize the tactical parameters of both fleets concurrently according to their chosen options. The parameters to be optimized include take-off time delay of fighters, launch time delay of anti-ship missiles (ASHMs), and initial flying directions of fighters and ASHMs, respectively. All six possible contests between options are simulated and analyzed in terms of payoff, impact scores on CV, CG, DDG, and the number of lost fighters. Some interesting outlier cases are inspected to gain some insights on this game.