In this paper, we address the problem of enclosing an arbitrarily moving target in three dimensions by a single pursuer, which is an unmanned aerial vehicle (UAV), for maximum coverage while also ensuring the pursuer's safety by preventing collisions with the target. The proposed guidance strategy steers the pursuer to a safe region of space surrounding the target, allowing it to maintain a certain distance from the latter while offering greater flexibility in positioning and converging to any orbit within this safe zone. Our approach is distinguished by the use of nonholonomic constraints to model vehicles with accelerations serving as control inputs and coupled engagement kinematics to craft the pursuer's guidance law meticulously. Furthermore, we leverage the concept of the Lyapunov Barrier Function as a powerful tool to constrain the distance between the pursuer and the target within asymmetric bounds, thereby ensuring the pursuer's safety within the predefined region. To validate the efficacy and robustness of our algorithm, we conduct experimental tests by implementing a high-fidelity quadrotor model within Software-in-the-loop (SITL) simulations, encompassing various challenging target maneuver scenarios. The results obtained showcase the resilience of the proposed guidance law, effectively handling arbitrarily maneuvering targets, vehicle/autopilot dynamics, and external disturbances. Our method consistently delivers stable global enclosing behaviors, even in response to aggressive target maneuvers, and requires only relative information for successful execution.

翻译：本文研究单个追踪飞行器（无人机）在三维空间中环绕任意运动目标的问题，旨在实现最大覆盖范围的同时，通过避免与目标碰撞确保追踪飞行器的安全性。所提出的制导策略将追踪飞行器引导至目标周围的安全空间区域，使其在保持与目标特定距离的同时，能够在该安全区内更灵活地定位并收敛至任意轨道。本方法的特色在于采用非完整约束对加速度作为控制输入的飞行器进行建模，并利用耦合交战运动学精心设计追踪飞行器的制导律。此外，我们借助李雅普诺夫屏障函数的概念，将其作为强大工具以非对称边界约束追踪飞行器与目标间的距离，从而确保追踪飞行器在预设区域内的安全性。为验证算法的有效性与鲁棒性，我们通过在软件在环仿真中实现高保真四旋翼模型进行了实验测试，涵盖了多种具有挑战性的目标机动场景。所得结果证明了所提制导律的强适应性，能有效应对任意机动的目标、飞行器/自动驾驶仪动力学及外部干扰。即使在应对激进的目标机动时，本方法仍能持续提供稳定的全局环绕行为，且仅需相对信息即可成功执行。