This paper addresses the problem of visual target tracking in scenarios where a pursuer may experience intermittent loss of visibility of the target. The design of a Switched Visual Tracker (SVT) is presented which aims to meet the competing requirements of maintaining both proximity and visibility. SVT alternates between a visual tracking mode for following the target, and a recovery mode for regaining visual contact when the target falls out of sight. We establish the stability of SVT by extending the average dwell time theorem from switched systems theory, which may be of independent interest. Our implementation of SVT on an Agilicious drone [1] illustrates its effectiveness on tracking various target trajectories: it reduces the average tracking error by up to 45% and significantly improves visibility duration compared to a baseline algorithm. The results show that our approach effectively handles intermittent vision loss, offering enhanced robustness and adaptability for real-world autonomous missions. Additionally, we demonstrate how the stability analysis provides valuable guidance for selecting parameters, such as tracking speed and recovery distance, to optimize the SVT's performance.

翻译：本文研究了在追踪者可能间歇性丢失目标可见性的场景下的视觉目标跟踪问题。提出了一种切换视觉跟踪器（SVT）的设计，旨在满足同时保持接近性和可见性的竞争性要求。SVT在用于跟随目标的视觉跟踪模式与当目标脱离视线时用于重新建立视觉接触的恢复模式之间交替切换。我们通过扩展切换系统理论中的平均驻留时间定理，建立了SVT的稳定性，该扩展本身可能具有独立的研究价值。我们在Agilicious无人机[1]上对SVT的实现，展示了其在跟踪各种目标轨迹方面的有效性：与基线算法相比，它将平均跟踪误差降低了高达45%，并显著提高了可见性持续时间。结果表明，我们的方法有效处理了间歇性视觉丢失问题，为现实世界的自主任务提供了更强的鲁棒性和适应性。此外，我们还展示了稳定性分析如何为选择参数（例如跟踪速度和恢复距离）以优化SVT的性能提供有价值的指导。