A Differential Game Approach to Collision-Aware Multi-Agent Target Defense in 3D UAV Systems

Abstract

This paper presents a differential game-based framework for defending a stationary target in three-dimensional (3D) space using autonomous unmanned aerial vehicles (UAVs). The scenario involves a single attacker attempting to reach the target while multiple defenders coordinate to intercept it. Each agent is modeled using position-level single-integrator dynamics for high-level control design. The interaction is cast as a continuous-time zero-sum game with a quadratic cost functional, where optimal strategies are derived using a time-varying Riccati differential equation. To ensure safe coordination during close-proximity operations, collision avoidance is incorporated via repulsion-based augmentation of defender controls. Furthermore, the high-level control inputs are tracked using a low-level proportional-derivative (PD) controller within a realistic 6-DOF UAV dynamic model implemented in Simulink. Simulation results validate the effectiveness of the proposed framework in achieving successful interception while maintaining defender safety and realistic trajectory tracking. © 2025 IEEE.