Unmanned Aircraft Systems (UAS) are being increasingly used in delivery, infrastructure surveillance, fire-fighting, and agriculture. According to the Federal Aviation Administration (FAA), the number of active small commercial unmanned aircraft is going to grow from 385K in 2019 to 828K by 2024. UAS traffic management (UTM) system for low-altitude airspace is therefore immediately necessary for its safe and high-density use. In this paper, we propose the first formalization of FAA's Concept of Operations for UTM for building and analyzing traffic management protocols and systems. We formalize FAA's notion of operation volumes (OVs) that express aircraft intent in terms of 4D blocks of airspace and associated real-time deadlines. We present a prototype coordination protocol using OVs, involving participating aircraft and an airspace manager. We formally analyze the safe separation and liveness properties of the protocol. Our analyses showcase how the de-conflicting and liveness of the system can be proven assuming each aircraft conforms to the deadlines specified by OVs. Through extensive simulations, we evaluate the performance of the protocol in terms of workload and response delays. Our experiments show that the workload on the airspace manager and the response time of each aircraft grow linearly with respect to the number of aircraft. The experiments also delineate the trade-off between performance, workload, and violation rate across different strategies for generating OVs. Lastly, we implement a UTM violation detection and resolution mechanism on top of our protocol. We include a simple fault injection technique that introduces failures with different probabilities. We demonstrate how to use it to empirically evaluate the impact of aircraft failure on the safety of surrounding aircraft, and how the performance of the airspace manager changes under different failure probabilities.

中文翻译：

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无人空中交通管理 (UTM)：形式化、原型实施和性能评估

无人机系统 (UAS) 越来越多地用于交付、基础设施监视、消防和农业。据美国联邦航空管理局 (FAA) 称，现役小型商用无人机的数量将从 2019 年的 38.5 万架增加到 2024 年的 82.8 万架。和高密度使用。在本文中，我们提出了 FAA 的 UTM 运营概念的首次形式化，用于构建和分析交通管理协议和系统。我们将 FAA 的运营量 (OV) 概念正式化，该概念以 4D 空域块和相关的实时截止日期来表达飞机意图。我们提出了一个使用 OV 的原型协调协议，涉及参与的飞机和空域管理者。我们正式分析了协议的安全分离和活性特性。我们的分析展示了如何在假设每架飞机都符合 OV 指定的截止日期的情况下证明系统的去冲突和活跃性。通过广泛的模拟，我们评估了协议在工作负载和响应延迟方面的性能。我们的实验表明，空域管理器的工作量和每架飞机的响应时间随飞机数量呈线性增长。实验还描绘了生成 OV 的不同策略之间的性能、工作负载和违规率之间的权衡。最后，我们在我们的协议之上实施了 UTM 违规检测和解决机制。我们包括一个简单的故障注入技术，它引入了不同概率的故障。我们演示了如何使用它来实证评估飞机故障对周围飞机安全的影响，以及空域管理器在不同故障概率下的性能如何变化。