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

Abstract: 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.