With the development of the Internet of Things, millions of sensors are being deployed in cities to collect real-time data. This leads to a need for checking city states against city requirements at runtime. In this article, we develop a novel spatial-temporal specification-based monitoring system for smart cities. We first describe a study of over 1000 smart city requirements, some of which cannot be specified using the existing logic, such as the signal temporal logic (STL) and its variants. To tackle this limitation, we develop spatial aggregation STL (SaSTL)-a novel spatial aggregation STL-for the efficient runtime monitoring of safety and performance requirements in smart cities. We develop two new logical operators in SaSTL to augment STL for expressing spatial aggregation and spatial counting characteristics that are commonly found in real city requirements. We define the Boolean and quantitative semantics for SaSTL in support of the analysis of city performance across different periods and locations. We also develop efficient monitoring algorithms that can check the SaSTL requirement in parallel over multiple data streams (e.g., generated by multiple sensors distributed spatially in a city). Additionally, we build an SaSTL-based monitoring tool to support decision making of different stakeholders to specify and runtime monitor their requirements in smart cities. We evaluate our SaSTL monitor by applying it to three case studies with large-scale real city sensing data (e.g., up to 10 000 sensors in one study). The results show that SaSTL has a much higher coverage expressiveness than other spatial-temporal logics, and with a significant reduction of computation time for monitoring requirements. We also demonstrate that the SaSTL monitor improves the safety and performance of smart cities via simulated experiments.

中文翻译：

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一种新型的基于时空规范的智慧城市监控系统


随着物联网的发展，数以百万计的传感器被部署在城市中以收集实时数据。这导致需要在运行时根据城市要求检查城市状态。在本文中，我们为智慧城市开发了一种新颖的基于时空规范的监控系统。我们首先描述了对 1000 多个智慧城市需求的研究，其中一些需求无法使用现有逻辑来指定，例如信号时序逻辑 (STL) 及其变体。为了解决这一限制，我们开发了空间聚合 STL (SaSTL)——一种新颖的空间聚合 STL——用于对智慧城市的安全和性能要求进行有效的运行时监控。我们在 SaSTL 中开发了两个新的逻辑运算符来增强 STL，以表达真实城市需求中常见的空间聚合和空间计数特征。我们为 SaSTL 定义了布尔和定量语义，以支持不同时期和地点的城市绩效分析。我们还开发了高效的监控算法，可以通过多个数据流（例如，由城市中空间分布的多个传感器生成）并行检查 SaSTL 要求。此外，我们构建了一个基于 SaSTL 的监控工具来支持不同利益相关者的决策，以指定和运行时监控他们在智慧城市中的需求。我们通过将 SaSTL 监测器应用于具有大规模真实城市传感数据的三个案例研究（例如，一项研究中多达 10 000 个传感器）来对其进行评估。结果表明，SaSTL比其他时空逻辑具有更高的覆盖表达能力，并且显着减少了监控需求的计算时间。 我们还通过模拟实验证明 SaSTL 监控器可以提高智慧城市的安全性和性能。