CPS: Breakthrough: Analysis, Identification and Mitigation of Delay Performance Bottlenecks of Network Infrastructure in Cyber-Physical Systems

现代社会正在见证建立在网络基础设施上的各种分布式网络物理系统（CPS）的流行。关键任务CPS应用的国际标准，如工业过程控制系统和航空电子设备，要求其网络基础设施提供确定性延迟性能。然而，将CPS理论概念与现实世界的网络性能相结合的问题在很大程度上仍未得到探索。该项目解决了这个开放的问题，以便可以正式分析网络挑战空间中的反馈控制CPS。该项目的成果可以应用于许多其他涉及实时控制和自适应的CPS应用领域，如车辆控制和通信系统、工业过程控制和片上网络系统。更广泛的影响包括为研究界开发公开可用的开源软件，并通过提供研讨会和教程以及组织研讨会来教育广泛的受众，从高中和本科生到学术和工业研究人员，以最大限度地提高代表性不足群体的参与。该项目的主要目标是建立一个系统的方法来设计、表征和改进CPS中的网络基础设施，作为设计和实施具有时间关键任务的CPS的突破性成果。与现有的依赖于预定义或假定的设备/系统规范的研究不同，新方法通过探索基于网络计算的网络设备建模和来自测量的流量源，平衡了理论分析和经验评估。与针对前馈网络的最先进方法相比，该项目还侧重于非前馈网络，包括对非前馈网络延迟性能分析的组合、代数和基于优化的方法的研究，以及对网络CPS延迟性能瓶颈的识别和缓解的研究。本项目将使用基于PLC（可编程逻辑控制器）的工业自动化系统进行案例研究，不仅展示了系统方法的使用和功能，还提供了相关算法的参考实现。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Modern societies are witnessing the prevalence of a wide assortment of distributed cyber-physical systems (CPS) built upon network infrastructure. International standards for mission-critical CPS applications, such as industrial process control systems and avionics, require their network infrastructure to provide deterministic delay performance. However, the problem of integrating CPS theoretical concepts with real-world network performance remains largely unexplored. This project addresses this open problem so that feedback control CPS in network-challenged spaces can be analyzed formally. The project result can be applied to many other CPS application domains involving real-time control and adaptation, such as vehicular control and communication systems, industrial process control, and network-on-chip systems. Broader impacts include developing publicly-available open-source software for the research community and educating a wide spectrum of audience, from high-school and undergraduate students to academic and industry researchers, by offering seminars and tutorials and organizing a workshop with strategies to maximize the participation of under-represented groups.The main goal of this project is to establish a systematic approach to the design, characterization, and refinement of network infrastructure in CPS as a breakthrough result for designing and implementing CPS with time-critical tasks. Different from existing studies relying on predefined or presumed device/system specifications, the new approach balances theoretical analyses with empirical evaluations by exploring network-calculus-based modeling of networking devices and traffic sources from measurements. This project also focuses on non-feedforward networks, in contrast to state-of-the-art methods targeting feedforward networks, and includes investigation of compositional, algebraic, and optimization-based approaches to delay performance analysis of non-feedforward networks and research on identification and mitigation of delay performance bottlenecks in networked CPS. This project will use PLC (Programmable Logic Controller)-based industrial automation systems for case studies, not only demonstrating the usage and capabilities of the systematic approach but also providing reference implementation of related algorithms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.