Generation Of Cyber-physical Systems Research Articles

Immersive Digital Twin under ISO 23247 Applied to Flexible Manufacturing Processes

Digital twin (DT) technology provides a path for implementing cyber–physical systems (CPS) and developing smart manufacturing because they are essential tools for monitoring and controlling manufacturing processes. It is considered a vital technology in smart manufacturing and is being widely researched in academia and industry. Furthermore, the combination of DTs and immersive environments has shown great potential for integrating novel capabilities into the new generation of CPS. This research presents an architecture for implementing immersive digital twins under ISO 23247 in flexible manufacturing processes. The proposed system is based on the integration of DT technologies in conjunction with augmented reality (AR) and gesture tracking, and validation was performed in the sorting station of the MPS 500 to increase the interaction and flexibility between physical and virtual environments in real time, thus enhancing the capabilities of the DT. The methodology used for the design and implementation of the DT includes (1) general principles and requirements; (2) models with functional views based on domains and entities; (3) attributes of the observable manufacturing elements; and (4) protocols for the exchange of information between entities. The results show that the integration of these technologies improves the monitoring, control, and simulation capabilities of processes using 3D resources and immersive environments, achieving a higher level of interactivity. In addition, error detection tests were carried out, where a reduction of time was observed in the resolution of errors that may be caused by internal or external disturbances of the process, thus avoiding production delays.

Security Perspective Analysis of Industrial Cyber Physical Systems (I-CPS): A Decade-wide Survey

Considering the exceptional growth of Cyber Physical Systems (CPSs), multiple and potentially grave security challenges have emerged in this field. Different vulnerabilities and attacks are present in front of new generation CPSs, such as Industrial CPS (I-CPS). The underlying non-uniform standards, device heterogeneity, network complexity, etc., make it difficult to offer a systematized coverage on CPS security in an industrial environment. This work considers the security perspective of I-CPSs, and offers a decade-wide survey including different vulnerabilities, attacks, CPS components, and various other aspects. The comparative year-wise analysis of the existing works w.r.t objective, approach referred, testbed used and derived inference, is also presented over a decade. Additionally, the work details different security issues and research challenges present in I-CPS. This work attempts to offer a concise and precise literature study focused on the state-of-the-art I-CPS security. This work also encourages the young researchers to explore the wide possibilities present in this emerging field.

Towards next generation cyber-physical systems and digital twins for construction

The construction industry continues to seek innovative ways to safely, timely and cost-effectively deliver construction projects. Several efforts have been made to automate construction processes but marginial success has been achieved in effectively reducing the long standing risks suffered by the industry. While industry 4.0 promises to improve project efficiency, reduce waste and improve productivity, the transition to this will depend on the successful adoption of many emerging technologies such as virtual design modeling technologies, sensing technologies, data analysis, storage and communication technologies, human-computer interaction technologies, and robotics. To accelerate innovation, digital twins and cyber-physical systems will be a necessity to advance automation and real-time control with these technologies. While digital twin represents a digital replica of the asplanned and as-built facility, cyber physical systems involve integration of physical systems with their digital replica through sensors and actuators. Despite evidence of the efficacy of cyber-physical systems and digital twins for reducing non-fatal injuries, enhancing safety management, improving progress monitoring and enhancing performance monitoring and control of facilities, their adoption in the construction industry is still in its infancy. This paper sheds light on the opportunities offered by cyber-physical systems and digital twins in other industry sectors and advocates for their increased deployment in the construction industry. This paper describes cyber-physical integration of emerging technologies with the physical construction or constructed facility as the next generation digital twin and cyber-physical systems. Potential scenarios of next generation cyber physical system and digital twin for improving workforce productivity, health, and safety, lifecycle management of building systems, and workforce competency are presented.

Introduction to the Special Issue on Decentralized Blockchain Applications and Infrastructures for Next Generation Cyber-Physical Systems

introduction Introduction to the Special Issue on Decentralized Blockchain Applications and Infrastructures for Next Generation Cyber-Physical Systems Share on Editors: Kim Kwang Raymond Choo University of Texas at San Antonio University of Texas at San AntonioView Profile , Uttam Ghosh Vanderbilt University Vanderbilt UniversityView Profile , Deepak Tosh University of Texas El Paso University of Texas El PasoView Profile , Reza M. Parizi Kennesaw State University Kennesaw State UniversityView Profile , Ali Dehghantanha University of Guelph University of GuelphView Profile Authors Info & Claims ACM Transactions on Internet TechnologyVolume 21Issue 2June 2021 Article No.: 38epp 1–3https://doi.org/10.1145/3464768Online:15 June 2021Publication History 0citation68DownloadsMetricsTotal Citations0Total Downloads68Last 12 Months68Last 6 weeks5 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

Staleness Control for Edge Data Analytics

A new generation of cyber-physical systems has emerged with a large number of devices that continuously generate and consume massive amounts of data in a distributed and mobile manner. Accurate and near real-time decisions based on such streaming data are in high demand in many areas of optimization for such systems. Edge data analytics bring processing power in the proximity of data sources, reduce the network delay for data transmission, allowlargescale distributed training, and consequently help meeting real-time requirements. Nevertheless, the multiplicity of data sources leads to multiple distributed machine learning models that may suffer from sub-optimal performance due to the inconsistency in their states. In this work, we tackle the insularity, concept drift, and connectivity issues in edge data analytics to minimize its accuracy handicap without losing its timeliness benefits. Thus, we propose an efficient model synchronization mechanism for distributed and stateful data analytics. Staleness Control for Edge Data Analytics (SCEDA) ensures the high adaptability of synchronization frequency in the face of an unpredictable environment by addressing the trade-off between the generality and timeliness of the model.

Staleness Control for Edge Data Analytics

A new generation of cyber-physical systems has emerged with a large number of devices that continuously generate and consume massive amounts of data in a distributed and mobile manner. Accurate and near real-time decisions based on such streaming data are in high demand in many areas of optimization for such systems. Edge data analytics bring processing power in the proximity of data sources, reduce the network delay for data transmission, allow large-scale distributed training, and consequently help meeting real-time requirements. Nevertheless, the multiplicity of data sources leads to multiple distributed machine learning models that may suffer from sub-optimal performance due to the inconsistency in their states. In this work, we tackle the insularity, concept drift, and connectivity issues in edge data analytics to minimize its accuracy handicap without losing its timeliness benefits. To this end, we propose an efficient model synchronization mechanism for distributed and stateful data analytics. Staleness Control for Edge Data Analytics (SCEDA) ensures the high adaptability of synchronization frequency in the face of an unpredictable environment by addressing the trade-off between the generality and timeliness of the model. Making use of online reinforcement learning, SCEDA has low computational overhead, automatically adapts to changes, and does not require additional data monitoring.

System‐of‐systems tools and techniques for the analysis of cyber‐physical systems

AbstractDynamic and real‐time adaptive configuration of Cyber‐Physical Systems (CPSs) results in increased complexity due to a variety of heterogeneous and interdependent variables and creates unique challenges. For example, (a) Emergent Behavior: How do we ensure that system constituents dynamically and adaptively collaborate to produce a consistent repeatable functionality while supporting the capability to upgrade the individual entities through technology infusion; (b) Scale: How do we ensure scalability of these systems by managing complexity; and (c) Risk Management: How do we evaluate and manage the risks associated with the connection and interdependencies of heterogenous systems. Design and development of this new generation of CPSs can be viewed through the lens of System‐of‐Systems (SoS) methodology which is designed to analyze and assess the evolving topologies created by interactions within a large complex system operating in dynamic and uncertain environment. In this paper, we propose the use of several SoS tools and techniques for the analysis and design of next‐generation CPSs. Our SoS methodologies address features such as diversity of component systems, complex hierarchical structures, dynamic and emergent behavior, and interactions between components. Therefore, they are suitable to treat some of the challenging features of CPSs. However, it is necessary to modify these methodologies to address specific aspects of CPSs. Constraints and metrics from SoS methodology, applied to the design space, will support decision on component systems and the topology of their connections, and provide a set of “good designs,” with desired characteristics.

Self-Adaptation Techniques in Cyber-Physical Systems (CPSs)

Cyber-Physical Systems (CPSs) are large-scale complex systems that monitor and control physical processes by using computer algorithms tightly integrated with networking and their users. Monitoring and controlling the physical environment is a hot topic for today's researchers and engineers in academia and industry. Within this realm, an important feature of current and future Information and Communications Technology (ICT) systems is self-adaptation-yet there is a shortage of information focusing on this characteristic in the literature, particularly as it relates to CPSs. Here, we investigate current state-of-the-art research on CPSs from this perspective, and evaluate the main self-adaptive approaches proposed in the literature, along with their results, strengths, and weaknesses. We also discuss appropriate techniques for enabling self-adaptation capabilities within CPSs at different architectural layers. Overcoming the challenges associated with designing and implementing self-adaptive mechanisms in CPSs will provide a path for bolstering a new generation of CPSs with greater robustness and reliability.

Architecture of homeostatic security control for digital manufacture systems based on software-defined networks

The authors have offered the homeostatic control system architecture for digital manufacture security based on the software-defined network technology. We have highlighted the development features of digital manufacture systems and defined the technology advantages of software- defined networks, which allow these networks to be successfully applied with flexible and adaptive topology for a highly efficient new generation of cyber-physical systems. We have also described the main operating principles of software-defined networks in digital manufacture systems. A description of homeostatic security control technology, which includes a combination of engines to provide stability of the system’s internal environment and structural and functional resistance to external disturbances, is provided. We have proposed and described in detail the homeostatic security control system architecture including three generalized components: monitoring unit, decision-making unit, protection and control unit.

Cyber-Physical Systems Security—A Survey

With the exponential growth of cyber-physical systems (CPS), new security challenges have emerged. Various vulnerabilities, threats, attacks, and controls have been introduced for the new generation of CPS. However, there lack a systematic study of CPS security issues. In particular, the heterogeneity of CPS components and the diversity of CPS systems have made it very difficult to study the problem with one generalized model. In this paper, we capture and systematize existing research on CPS security under a unified framework. The framework consists of three orthogonal coordinates: (1) from the \emph{security} perspective, we follow the well-known taxonomy of threats, vulnerabilities, attacks and controls; (2)from the \emph{CPS components} perspective, we focus on cyber, physical, and cyber-physical components; and (3) from the \emph{CPS systems} perspective, we explore general CPS features as well as representative systems (e.g., smart grids, medical CPS and smart cars). The model can be both abstract to show general interactions of a CPS application and specific to capture any details when needed. By doing so, we aim to build a model that is abstract enough to be applicable to various heterogeneous CPS applications; and to gain a modular view of the tightly coupled CPS components. Such abstract decoupling makes it possible to gain a systematic understanding of CPS security, and to highlight the potential sources of attacks and ways of protection.

Towards an experience based collective computational intelligence for manufacturing

Knowledge based support can play a vital role not only in the new fast emerging information and communication technology based industry, but also in traditional manufacturing. In this regard, several domain specific research endeavours have taken place in the past with limited success. Thus, there is a need to develop a flexible domain independent mechanism to capture, store, reuse, and share manufacturing knowledge. Consequently, innovative research to develop knowledge representation models of an engineering object and engineering process called Virtual engineering object (VEO) and Virtual engineering process (VEP) has been carried out and extensively reported. This paper proposes Virtual engineering factory (VEF), the final phase to create complete virtual manufacturing environment which would make use of the experience and knowledge involved in the factory at all levels. VEF is an experience based knowledge representation for a factory encompassing VEP and VEO within it. The novelty of this approach is that it uses manufacturer’s own previous experience and formal decisions to collect and expand intelligence for future production. The experience based collective computational techniques of Set of Experience Knowledge Structure (SOEKS) and Decisional DNA (DDNA) are used to develop aforesaid models. In this article the concept and architecture of VEF is explained as well as the integration of all three levels of virtual manufacturing i.e. VEO, VEP and VEF is presented. Furthermore, a case-study is presented to validate the practical implementation of the proposed concept. The benefits of this approach are manifold as it creates the environment for collective intelligence of a factory and enhances effective decision making. The models and research presented here embody the important first step into developing the future computational setting as required by the emerging next generation of cyber-physical systems.

Analysis and design of secure cyber-physical systems

Cyber-physical systems (CPSs) are new emerging systems that seamlessly integrate physical systems, communication systems and computation systems. Their wide use has been witnessed in the past decades in many crossdiscipline fields such as smart energy systems, industrial process control, aerospace and automobile engineering, health-care and assisted living, to just name a few. For many of these systems, secure operations are of key concerns. In particular, for some safety-critical applications, security is of paramount importance. Diverse motivations and strong incentives exist everywhere and at any time for launching malicious attacks on the CPSs, for example, economic reasons (e.g., by reducing or even not paying electricity charge) and terrorism the purpose of which is apparent. Unlike traditional wired and point-to-point control systems where an attacker may not easily launch any attack, the new generation CPSs widely utilize existing network infrastructure such as wireless communications, local area networks, etc., for information delivery and high-level supervisory monitoring and control. This, although brings unprecedented convenience to the system design and implementation, introduces security loopholes to the closedloop system where an attacker may launch various types of popular attacks that have rooted deeply in the intrinsic architecture of the network protocols pervasively used today. For example, attackers may launch the so-called Denialof-Service (DoS) attacks and may eavesdrop a communication channel and learn the content of the transmitted data when the data is conveyed over wireless channels. Worst of all, the attackers may intercept the data, inject some malicious content into it, and then send it out as if the data were intact. By properly manipulating the data content, the attackers may control the entire system and steer the system state to any arbitrary positions. Secure data transmission is almost taken for granted in early research of CPSs. Data imperfection is indeed widely considered. The models of such imperfection (e.g., in terms of random data packet drops and delays, quantization, etc.), however, are very much limited and do not include the possibility that the communicated data may not be the “true” data collected by the sensors or computed by the controllers, which may be already modified in a malicious way by the attackers. Very recently in July 2010, Stuxnet, which is a control system malware and targets vulnerable Supervisory Control And Data Acquisition (SCADA) systems in a power grid, raises new questions and inspires novel research on cyber-physical system security. The control and systems community has made significant progress in analyzing security issues arising in a CPS and designing counter measures to make the system more resilient to malicious attacks in the past few years. Various performance metrics have been proposed for different applications including indexes for state estimation (e.g., mean square errors of state estimation in a smart grid), feedback control (e.g., LQR or LQG cost of wireless networked control systems), etc. Most of the developed approaches, such as secure detection, estimation and robust control, which aim to identify the abnormality arising in a system state, can only provide limited counter measures to certain strict types of malicious attacks, such as replay attacks, DoS attacks, and integrity attacks on linear systems.

MA-LTRT: A Novel Method to Improve Network Connectivity and Power Consumption in Mobile Ad-hoc Based Cyber-Physical Systems

Recently, the development in wireless devices has made it possible to connect numerous devices by constructing networks only amongst themselves. Cyber-physical Systems (CPSs) are likely to emerge through such network environments to connect both humans and machines so that a smart society can evolve with remarkably convenient and yet foreseen pervasive communication. It is, however, difficult to establish adequate network infrastructures anywhere and anytime. Therefore, a critical research issue is to formulate an effective method for constructing networks. To address this issue, we focus on mobile ad-hoc based CPSs, which is a network system consisting of mobile devices. Because it does not require any specific facility, the mobile ad-hoc based CPS may be considered to be a good candidate for realizing next generation CPSs. It, however, presents two major research challenges, namely the difficulty to maintain high connectivity in the network constructed by only mobile nodes, and the need to reduce the power consumption of the nodes. For addressing these two challenges in the mobile ad-hoc based CPS, we propose a novel method called mobility aware, local tree-based reliable topology to construct the network with adequate network connectivity while ensuring a low level of power consumption.

Towards Middleware-Based Cooperation Topologies for the Next Generation of CPS

Cyber-Physical Systems (CPS) integrate embedded computers that control physical processes. Application domains for CPS may be found in intelligent buildings, healthcare, transportation and factory automation, among many others. Typically, they are based on low profile computing elements, such as sensors and actuators that must communicate to carry out complex tasks. They must address certain issues such as managing available resources and service redundancy, as well as solving heterogeneity. In particular, managing communication issues can be relatively complex. In this scenario, middleware technologies can help developers in the design of state-of-the-art CPS. This work describes the design principles of CPS that require cooperation. More specifically, it presents a generic family of logical information exchange and cooperation topologies capable of adapting dynamically to changes in the environment. These topologies may be implemented on top of several middleware specifications as a means for managing distributed resources and service redundancy of CPS at run-time.