With the introduction of the Internet of Things (IoT) and cyberphysical system (CPS) concepts in industrial application scenarios, industrial automation is undergoing a tremendous change. This is made possible in part by recent advances in technology that allow interconnection on a wider and more fine-grained scale. The purpose of this article is to review technological trends and the impact they may have on industrial communication. We will review the impact of IoT and CPSs on industrial automation from an industry 4.0 perspective, give a survey of the current state of work on Ethernet time-sensitive networking (TSN), and shed light on the role of fifth-generation (5G) telecom networks in automation. Moreover, we will point out the need for harmonization beyond networking.

The Future of Industrial Communication: Automation Networks in the Era of the Internet of Things and Industry 4.0

This paper reviews the recent development of Digital Twin technologies in manufacturing systems and processes, to analyze the connotation, application scenarios, and research issues of Digital Twin-driven smart manufacturing in the context of Industry 4.0. To understand Digital Twin and its future potential in manufacturing, we summarized the definition and state-of-the-art development outcomes of Digital Twin. Existing technologies for developing a Digital Twin for smart manufacturing are reviewed under a Digital Twin reference model to systematize the development methodology for Digital Twin. Representative applications are reviewed with a focus on the alignment with the proposed reference model. Outstanding research issues of developing Digital Twins for smart manufacturing are identified at the end of the paper.

/pdf/digital-twin-driven-smart-manufacturing-connotation-znpb1qad7f.pdf

Digital Twin-driven smart manufacturing: Connotation, reference model, applications and research issues

This book provides an in-depth description of event-based systems, covering topics ranging from local event matching and distributed event forwarding algorithms, through a practical discussion of software engineering issues raised by the event-based style, to state-of-the-art research in event-based systems like composite event detection and security. The authors offer a comprehensive overview, and show the power of event-based architectures in modern system design, encouraging professionals to exploit this technique in next generation large-scale distributed applications like information dissemination, network monitoring, enterprise application integration, or mobile systems.

/pdf/distributed-event-based-systems-33fttbtql7.pdf

Distributed event-based systems

In recent years, industrial wireless sensor networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems, and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment, and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper, a detailed discussion on design objectives, challenges, and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines, and possible hazards in industrial atmosphere are discussed. This paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. This paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs.

/pdf/a-critical-analysis-of-research-potential-challenges-and-14no6a3bs7.pdf

A Critical Analysis of Research Potential, Challenges, and Future Directives in Industrial Wireless Sensor Networks

Having gained momentum from its promise of centralized control over distributed network architectures at bargain costs, software-defined Networking (SDN) is an ever-increasing topic of research. SDN offers a simplified means to dynamically control multiple simple switches via a single controller program, which contrasts with current network infrastructures where individual network operators manage network devices individually. Already, SDN has realized some extraordinary use cases outside of academia with companies, such as Google, AT&T, Microsoft, and many others. However, SDN still presents many research and operational challenges for government, industry, and campus networks. Because of these challenges, many SDN solutions have developed in an ad hoc manner that are not easily adopted by other organizations. Hence, this paper seeks to identify some of the many challenges where new and current researchers can still contribute to the advancement of SDN and further hasten its broadening adoption by network operators.

Advancing Software-Defined Networks: A Survey

Networks in the automotive and aerospace area as well as in production facilities have to support time-critical (i.e., hard real-time) communication. For such applications, time-triggered Ethernet-based networking solutions provide the required timeliness, i.e., reliable packet delivery with deterministic latencies and low jitter. However, the routing and scheduling of the time-triggered traffic is an NP-hard problem. Hence, existing solutions to this problem make certain abstractions to reduce complexity if necessary. Nonetheless, such abstractions exclude feasible routing and scheduling options from the design space. Specifically, it is a typical approach to model routing and scheduling as separate problems, which are solved successively or with heuristic coupling. Therefore, we present a novel ILP formulation that can be used to jointly solve the routing and scheduling problem for time-triggered Ethernet networks. Using this formulation, it is possible to solve various scheduling problems that are infeasible when using a fixed shortest path routing with separate scheduling. Compared to a fixed load balanced routing with separate scheduling, schedules computed with our formulation offer lower communication latencies.

ILP-based joint routing and scheduling for time-triggered networks

For companies in the automation industry, the development of real-time Ethernet to connect devices is of high economic interest to replace conventional fieldbus systems Therefore, many approaches for adapting Ethernet to real-time requirements come from industrial applications This is a challenging task as the original Ethernet standard IEEE 8023 was not designed for real-time data transmission Likewise, protocols basing on Ethernet like TCP, UDP, and IP do typically not consider real-time requirements Hence, adaptations on several OSI layers become necessary to make the industrial system meet hard real-time requirements For this purpose, a multitude of realtime capable Industrial Ethernet systems has been developed, which solve the problems of standard Ethernet- and TCP/IP- or UDP/IP-based communication in a variety of ways This paper gives a summary of different Industrial Ethernet protocols for the real-time data transmission via Ethernet in automation environments Advantages and disadvantages of these protocols are analyzed with regard to their sustainability in terms of their realtime capability, reliability, scalability, self-configuration of the network, and hardware requirements Against the background of connected devices tremendously growing in number and computational power in the prospective “Industrial Internet”, consequences for future developments are drawn

/pdf/survey-on-real-time-communication-via-ethernet-in-industrial-1ke4t5dwqx.pdf

Survey on real-time communication via ethernet in industrial automation environments

Future applications of the Industrial Internet of Things will increasingly depend on the timely exchange of information and data. Time-Sensitive Networking, which is currently being standardized, therefore extends switched Ethernet networks by realtime communication capabilities offering deterministic message delays. In its time-triggered communication variant, a network path needs to be planned for each realtime data flow and corresponding transmission time slots have to be reserved on the network links along that path. In this paper, we present the first joint mathematical model for path routing and time slot scheduling that combines multicast support with an individual transmission scheduling on each link along a flow's path. We provide a formalization as an Integer Linear Programming (ILP) problem and discuss several optimizations to significantly reduce the ILP solver's runtime without affecting the solution quality. In a thorough evaluation, we show the applicability of our approach and analyze the effects and trade-offs of different objective functions.

ILP-Based Routing and Scheduling of Multicast Realtime Traffic in Time-Sensitive Networks

In industrial automation environments, networks providing a reliable and timely data delivery are required. Fulfilling this need, Industrial Ethernet (IE) systems have established as an important networking technology in many application areas. Although there are several IE solutions on the market, all of these systems have notable drawbacks, like limited scalability or the introduction of a Single Point of Failure (SPoF). Therefore, we propose a novel IE system that is based on Software Defined Networking (SDN). Originally meant for data center and IT networks, the SDN concept offers features like central network management functions and a fine-grained traffic control that allows to support many applications with diverse requirements even in the same network. Thereby, SDN is also perfectly suited for complex automation environments. To guarantee RT data transmission as well as scalability and an efficient resource usage, our IE system uses a Medium Access Control (MAC) scheme that is based on a Time Division Multiple Access (TDMA) mechanism that is extended by simultaneous data transmissions on physically separate links. The enhanced TDMA mechanism is configured by a joint routing and scheduling algorithm that takes application requirements into account. Our theoretical analysis as well as results achieved with a prototype implementation of the system confirm the applicability of our concept in demanding automation environments with applications that require a worst case communication latency below 1 ms.

Application-aware industrial ethernet based on an SDN-supported TDMA approach

This survey addresses the question if existing realtime capable Internet technologies for wired communication can meet the requirements of future industrial IoT scenarios with a rising number of heterogeneous devices to be connected and increasing amounts of data to be exchanged in real-time. The development towards an industrial IoT is further referred to as Industry 4.0 in Germany and Industrial Internet in the USA, respectively. We first investigate selected widespread technologies at all layers of the ISO/OSI model with respect to their realtime capability, scalability and dynamic reconfiguration, standard compliance and platform complexity as well their capability to integrate non-real-time devices. On the one hand, we note that TSN technology at physical and link layer is standardized but exhibits very high platform complexity for the switches and is thus costly. Subsequently, it is hence discussed if purely software-based approaches can enable RT communication over Ethernet. Moreover, even though TSN-enabled network components can enforce real-time behavior, scheduling and routing algorithms for computing the respective network configuration are not part of the TSN standards. Those algorithms could be executed on a central SDN controller to achieve high performance and realtime capability, however, the scalability of such a centralized approach is limited by the fact that corresponding algorithms have exponential computational complexity. Hence, one of the future research directions outlined proposes to trade off distributed against centralized scheduling and routing approaches with regard to scalability and dynamic reconfiguration, real-time capability, and platform complexity. We conclude there is a need for the advancement of existing and for the development of new, possibly hybrid, real-time capable approaches that combine the advantages of centralized and distributed solution in order to meet all requirements.

Eike Schweissguth

Papers

ILP-based joint routing and scheduling for time-triggered networks

Survey on real-time communication via ethernet in industrial automation environments

ILP-Based Routing and Scheduling of Multicast Realtime Traffic in Time-Sensitive Networks

Application-aware industrial ethernet based on an SDN-supported TDMA approach

Real- Time Capable Internet Technologies for Wired Communication in the Industrial IoT-a Survey