A New Layer Structure of Cyber-Physical Systems under the Era of Digital Twin

Abstract

Cyber-Physical Systems (CPS) are new systems designed to support and synthesize sensing, communication, and computing components that interact with physical objects so that the system can sense, monitor, control, and respond to changes occurring in their operating environments. With developing Internet of Things (IoT), edge/cloud computing, and Artificial Intelligence (AI), another new paradigm - Digital Twin (DT), as an enabler for realizing the Metaverse of CPS has emerged recently. The DT provides a virtual replica of the physical world, allowing for real-time monitoring, control, and analysis of safety-critical systems like the CPS. Even though many CPS-related problems can be addressed using DT concepts, it is critical to define DT’s integration clearly to leverage its features to the best possible extent. This paper introduces a new layer called the data layer in the CPS layer architecture to support different DT functionalities. Like the layer and abstract design paradigm of modern operation systems and computer networks, the data layer serves as an abstraction layer, providing immense flexibility and interchangeability of various data sources, supporting applications, and adapting to other components and environments. This also accelerates the growth of smart-world systems and their integration in different application domains (smart grid, smart transportation, smart manufacturing, smart cities, smart healthcare, etc.). To this end, this paper presents a new data layer structure to support CPS applications and the integration of multiple CPS. We propose a hierarchical architecture to synthesize DT techniques as an independent layer in our architecture, deeply integrated into existing CPS. We discuss key issues: leveraging the data layer to support applications in various CPS, incorporating the data layer and physical layer, and building a data layer using distributed computing, naming services, etc. Finally, the paper outlines future research directions based on the presented new data layer architecture for CPS.