Open Platform Communications Unified Architecture Research Articles

A Decision-Making Framework for the Smart Charging of Electric Vehicles Considering the Priorities of the Driver

During the last decade, the technologies related to electric vehicles (EVs) have captured both scientific and industrial interest. Specifically, the subject of the smart charging of EVs has gained significant attention, as it facilitates the managed charging of EVs to reduce disturbances to the power grid. Despite the presence of an extended literature on the topic, the implementation of a framework that allows flexibility in the definition of the decision-making objectives, along with user-defined criteria is still a challenge. Towards addressing this challenge, a framework for the smart charging of EVs is presented in this paper. The framework consists of a heuristic algorithm that facilitates the charge scheduling within a charging station (CS), and the analytic hierarchy process (AHP) to support the driver of the EV selecting the most appropriate charging station based on their needs of transportation and personal preferences. The communications are facilitated by the Open Platform Communications–Unified Architecture (OPC–UA) standard. For the selection of the scheduling algorithm, the genetic algorithm and particle swarm optimisation have been evaluated, where the latter had better performance. The performance of the charge scheduling is evaluated, in various charging tasks, compared to the exhaustive search for small problems.

Cloud-Manufacturing-Based Condition Monitoring Platform With 5G and Standard Information Model

Condition monitoring (CM) is the escort of smart manufacturing, which guarantees safety, precision, and efficiency of production process. However, traditional CM capacities with limited storage and computing resources cannot follow the explosive growth of manufacturing data. Empowered by the emerging Internet of Things, cyber–physical system, and cloud computing, cloud manufacturing (CMfg) characterizes a new service-oriented technology, which is reshaping the CM paradigm into an agile, scalable, and interoperable mode. In this article, a CMfg-based CM platform for smart manufacturing is proposed. A 5G wireless communication network-based edge computing system is presented to achieve data acquisition, feature extraction, and emergency response with ultrareliability and low-latency communication. In order to deal with the issue of data management and analysis, a generic open platform communications unified architecture information model oriented to the workshop is proposed in the fog layer. The cloud monitoring platform is constructed encompassing message delivery, data storage, status visualization, and training of artificial intelligence models. Finally, a CMfg-based CM system and a CMfg-based tool wear estimation system are outlined as two industrial cases. The experiments verify the feasibility and effectiveness of the proposed platform.

Improving OPC UA Publish-Subscribe Mechanism over UDP with Synchronization Algorithm and Multithreading Broker Application.

Communication protocols are evolving continuously as the interfacing and interoperability requirements are the foundation of Industry 4.0 and Industrial Internet of Things (IIoT), and the Open Platform Communication Unified Architecture (OPC UA) protocol is a major enabling technology. OPC UA was adopted by the industry, and research is continuously carried out to extend and to improve its capabilities, to fulfil the growing requirements of specific industries and hierarchical levels. Consistent issues that have to be approached are related to the latest specifications and the real-time context that could extend the applicability of the protocol and bring significant benefits in terms of speed, data volumes, footprint, security. The real-time context is essential in the automotive sector and it is highly developed within some specific protocols. The current work approaches first the conceptual analysis to improve the OPC UA interfacing using the Publish-Subscribe mechanism, focusing on real-time constraints and role distribution between entities, and considering some well-founded interfacing strategies from the automotive sector. The conceptual analysis is materialized into a solution that takes OPC UA Publish-Subscribe over User Datagram Protocol (UDP) mechanism to the next level by developing a synchronization algorithm and a multithreading broker application to obtain real time responsiveness and increased efficiency by lowering the publisher and the subscriber footprint and computational effort, reducing the difficulty of sending larger volumes of data for various subscribers and the charge on the network and services in terms of polling and filtering. The proof of concept is evaluated and the results prove the efficiency of the approach and the solution.

An OPC UA-Compliant Interface of Data Analytics Models for Interoperable Manufacturing Intelligence

The open platform communications unified architecture (OPC UA) has received attention as a standard for data interoperability in industries. In particular, OPC UA extends its applicability across various industrial sectors by publishing OPC UA companion specifications created in collaboration with other industrial consortiums. However, OPC UA is limited to ensure the interoperability of data analytics models because the relevant companion specifications have not been developed yet. OPC UA should be extended to implement such model interoperability so that machines seamlessly use and share data analytics models across the layers of manufacturing systems to predict and optimize their performance autonomously and collaboratively in terms of interoperable manufacturing intelligence. This article proposes an OPC UA-compliant interface for the exchange of predictive model markup language (PMML), a domain-independent standard for representing XML-based data analytics models. This article includes the design of mapping rules and OPC UA information models for the exchange between PMML and OPC UA, as well as the implementation of an OPC UA server-client prototype to publish and subscribe to OPC UA-compliant regression and neural network models which have been transformed from PMML-based models.

Multi-protocol bridge generation for M2M communication using MQTT

MQTT (Message Queuing Telemetry Transport) is known as a quasi-standard for IoT application communication between IoT devices and OPC UA (Open Platform Communication Unified Architecture) is the de facto standard that enables M2M communication in modern industry 4.0. But there are also industrial machines that still use RESTful (Representational State Transfer) APIs as their only communication interface. Integrating machines with these three protocols into automated manufacturing processes and enact a machine to machine communication between them can be challenging. This paper demonstrates how a M2M communication supporting HTTP, MQTT and OPC UA can be implemented using MQTT as the communication protocol. Furthermore, the goal is to create a model for each bridge that can be used to create interface mappings from MQTT to HTTP or from MQTT to OPC UA. This model can then easily be used to generate MQTT clients that bridge the different protocols and enable the M2M communication between machines to share their information.

The State of Integrated CAM/CNC Control Systems: Prior Developments and the Path Towards a Smarter CNC.

Current industrial practice in automated manufacturing operations relies on low fidelity data transmission methods between computer numerical control (CNC) machine tools and the computer-aided manufacturing (CAM) systems used to program them. The typical language used to program CNC machines, known as G-Code, has been in existence for nearly sixty years and offers limited resolution for command data. In addition, the proprietary nature of industrial CNC systems hampers the ability of manufacturers to expand and improve upon the capability of existing machine tools. G-Code was not designed to support transmission of feedback data, and thus both the CAM system and higher level organizational control systems are frequently blind to the state of the production process; in response, separate standards that enable data exchange with machine tools have been used by industry, such as MTConnect and Open Platform Communications Unified Architecture (OPC UA). However, these standards enable data pathways that are independent of the G-Code command data pathway, and thus provide practically no means to affect the state of a process on receipt of feedback data. As a result, control and data acquisition exist in separate realms, which makes the implementation of self-optimizing smart CNC systems challenging. This state-of-the-art review surveys existing methods for data transmission to and from machine tools and explores the current state of so-called integrated CAM/CNC systems that enable more thorough control of the machining process using intelligence built in to the CAM system. The literature survey reveals that integrated CAM/CNC systems are impeded both by the data exchange methods used to interface with CNC systems in addition to the proprietary and closed architecture of the CNC systems themselves. Future directions in integrated CAM/CNC research are identified based on the requirements identified for such systems.

A Smartphone Integrated Hand-Held Gap and Flush Measurement System for in Line Quality Control of Car Body Assembly.

This paper presents the design and the characterization of a portable laser triangulation measurement system for measuring gap and flush in the car body assembly process. Targeting Human in the Loop (HILT) operations in the manufacturing sector, and in line with the vision of human empowerment with Industry 4.0 technologies, the instrument embeds features to ease operators’ activity and compensate possible misuse that could affect the robustness and the quality of data acquired. The device is based on a smartphone integrated with a miniaturized laser triangulation system installed in a cover. The device embodies additional sensors and control systems in order to guarantee operators’ safety (switching on and off the laser line based on specific conditions), support operators during the measurement execution task, and optimize the image acquisition process for minimizing the uncertainty associated to the measurement. The smartphone performs on-board processing and allows Wi-Fi communication with the plant IT infrastructure. Compliance to Industry 4.0 requirements is guaranteed using OPC-UA (Open Platform Communications—Unified Architecture) communication protocol enabling the exchange of live data with the plant middleware. The smartphone provides also an advanced high-resolution color display and well proven and ergonomic human–machine interfaces, which have been fully exploited in the design. The paper introduces the system optical layout and then presents the algorithms implemented to realize the gap and flush measurement. The paper finally presents the calibration of the instrument and estimates its calibration uncertainty in laboratory conditions. Then it discusses how performance decays when the operator handles the instrument on a reference car body. Finally, it shows the analysis of uncertainty when the device is used on real car bodies of different colors in a production line. It is observed that the measurement uncertainty of the whole measurement chain (measurand + instrument + operator + uncontrolled environmental conditions) is larger than the instrument calibration uncertainty because the measurement process is affected by the operator and the variable conditions of the production line.

Insights into Mapping Solutions Based on OPC UA Information Model Applied to the Industry 4.0 Asset Administration Shell

In the context of Industry 4.0, lot of effort is being put to achieve interoperability among industrial applications. As the definition and adoption of communication standards are of paramount importance for the realization of interoperability, during the last few years different organizations have developed reference architectures to align standards in the context of the fourth industrial revolution. One of the main examples is the reference architecture model for Industry 4.0, which defines the asset administration shell as the corner stone of the interoperability between applications managing manufacturing systems. Inside Industry 4.0 there is also so much interest behind the standard open platform communications unified architecture (OPC UA), which is listed as the one recommendation for realizing the communication layer of the reference architecture model. The contribution of this paper is to give some insights behind modelling techniques that should be adopted during the definition of OPC UA Information Model exposing information of the very recent metamodel defined for the asset administration shell. All the general rationales and solutions here provided are compared with the current OPC UA-based existing representation of asset administration shell provided by literature. Specifically, differences will be pointed out giving to the reader advantages and disadvantages behind each solution.

Heterogeneous Connection and Process Anomaly Detection of Industrial Robot in Intelligent Factory

Since the concept of industry 4.0 was proposed in 2011, the trend of industry 4.0 has been surging around the world. Intelligent factory is one of the main research points in the industry 4.0 era. In order to improve the intelligent level of the factory, the connection-and-cognition ability has to be established for the factory and its equipment. Connection builds data pipes among equipment and systems while cognition automatically turns the data into knowledge. In an intelligent factory, industrial robot plays a leading role. Hence, the aim of this paper is to synthetically study connection and cognition of industrial robots in intelligent factories. To be specific, open platform communications unified architecture (OPC UA) is applied to establish heterogeneous connection of industrial robots with factory management software. A long short-term memory (LSTM) joint auto encoder method is proposed to establish the unsupervised anomaly detection cognition ability for industrial robot process (e.g. grinding, welding and assembling). In summary, this study puts OPC UA and LSTM auto encoder technology together to study heterogeneous connection and process anomaly detection of industrial robots in intelligent factory. The experimental results showed that the proposed method successfully realized heterogeneous connection of an industrial robot and detected process anomaly from the robot built-in sensors’ data.

Industrial Internet of Things and Fog Computing to Reduce Energy Consumption in Drinking Water Facilities

The industry is generally preoccupied with the evolution towards Industry 4.0 principles and the associated advantages as cost reduction, respectively safety, availability, and productivity increase. So far, it is not completely clear how to reach these advantages and what their exact representation or impact is. It is necessary for industrial systems, even legacy ones, to assure interoperability in the context of chronologically dispersed and currently functional solutions, respectively; the Open Platform Communications Unified Architecture (OPC UA) protocol is an essential requirement. Then, following data accumulation, the resulting process-aware strategies have to present learning capabilities, pattern identification, and conclusions to increase efficiency or safety. Finally, model-based analysis and decision and control procedures applied in a non-invasive manner over functioning systems close the optimizing loop. Drinking water facilities, as generally the entire water sector, are confronted with several issues in their functioning, with a high variety of implemented technologies. The solution to these problems is expected to create a more extensive connection between the physical and the digital worlds. Following previous research focused on data accumulation and data dependency analysis, the current paper aims to provide the next step in obtaining a proactive historian application and proposes a non-invasive decision and control solution in the context of the Industrial Internet of Things, meant to reduce energy consumption in a water treatment and distribution process. The solution is conceived for the fog computing concept to be close to local automation, and it is automatically adaptable to changes in the process’s main characteristics caused by various factors. The developments were applied to a water facility model realized for this purpose and on a real system. The results prove the efficiency of the concept.

Design of software-defined gateway for industrial interconnection

Abstract Industrial site interconnection is regarded as the focus of Industrie 4.0. However, there are various types of equipment and communication interfaces on the industrial site, and it is difficult to unify numerous heterogeneous protocols. Herein, based on the idea of software-defined, a smart gateway is rationally designed for industrial interconnection scenes with hardware platformization and software modularization. The function, interface, and parameters of the gateway can be defined. Moreover, it can conveniently and quickly connect with multiple heterogeneous devices. Therefore, this well-designed gateway offers an opportunity for equipment data collection, normalization processing and transmission protocol conversion to OPC UA (Open Platform Communications Unified Architecture) or MQTT (Message Queuing Telemetry Transport). As demonstrated in test results, this gateway obtains an advanced design concept, scalable architecture and strong applicability in heterogeneous scenes.

Evaluation of OPC-UA communication in an autonomous advanced manufacturing cell implementation

Abstract: The recent development of advanced manufacturing concepts brings new challenges for developing countries in order to prepare their workforce and industries for local and global markets. To explore and disseminate advanced manufacturing concepts, the first autonomous advanced manufacturing cell developed in Brazil as a result of a partnership between global and local companies and academia was designed and evaluated. This paper aims to describe the advanced manufacturing cell, the equipment composing the infrastructure, and the network topology and equipment that could deal with the heterogeneity of equipment and protocol. Moreover, the behavior of the Open Platform Communications Unified Architecture (OPC UA) communication framework (and related protocols) as the integration element between the equipment composing the cell was evaluated. The results indicated that the OPC UA communication framework promotes a low traffic overhead and can also be used to carry data from the traditional protocols in their fields without restrictions that could hinder production. The paper also discusses how the exchange of data occurred between the equipment used in the production and the control systems via the protocol studied. The OPC UA communication framework protocols presented a messaging structure and data transport characteristics that satisfy the integration needs between equipment of several manufacturers that composed an autonomous cell of advanced manufacturing. This paper also presents some key challenges to integrating all equipment not addressed by the OPC UA reference model.

Practical Implementation of an OPC UA TSN Communication Architecture for a Manufacturing System

In modern manufacturing systems, various industrial communication systems (e.g., fieldbus systems and industrial Ethernet networks) have been used to realize reliable information exchange. However, these industrial communication solutions are largely incompatible with each other, which do not satisfy the new requirements of Industry 4.0. Recently Time-Sensitive Networking (TSN) has been developed to improve the real-time capabilities to the standard Ethernet, and is considered to be a promising real-time communication solution for Industry 4.0. In this work, we propose a communication architecture for a manufacturing system using the Open Platform Communications Unified Architecture (OPC UA) and TSN technologies. TSN is adopted as the communication backbone to connect heterogeneous industrial automation subsystems. The OPC UA is adopted to realize horizontal and vertical communication between subsystems in the field layer and the entities of the upper layers. We implement a laboratory-level manufacturing system to validate the proposed architecture. The experimental results demonstrate the feasibility and capability of the proposed architecture. Moreover, we evaluate the performance of a key TSN substandard, i.e., IEEE 802.1Qbv, in the laboratory-level manufacturing system. The evaluation results demonstrate that IEEE 802.1Qbv can indeed provide excellent real-time capabilities for industrial applications.

From Digital Shop floor to Real-Time Reporting: an IIoT Based Educational Use Case

The Smart Production Lab (Lab)at the FH JOANNEUM in Kapfenberg, Austria, is a digital learning and research factory with an interdisciplinary focus on vertical and horizontal IT-integration. It is aiming at a higher transparency and productivity by applying latest digital technologies. The key technology is the Industrial Internet of Things (IIoT). Therefore, research driven IoT use cases are further developed such as hybrid IoT-concepts and architectures involving edge and cloud computing. State-of-the-Art use cases apply of-the-shelf technologies for ready-to-use implementations and teaching purposes. This paper introduces a case-based teaching concept in the area of IIoT. It provides students with a hands-on experience as well as deep insights in what is meant by modelling and implementing an IoT data flow from the shop floor to real-time reporting. For this purpose, on the operational technology (OT) layer IoT nodes were attached to the machinery in the Lab gathering and providing data for the IoT middleware layer, based on Open Platform Communication Unified Architecture (OPC UA). This central middleware-layer is represented by the open source platform Node-RED. In the respective use case the data is transformed in order to be stored in a NoSQL database, from where it can be accessed for real-time reporting either by cloud or on premise applications. The interdisciplinary nature of these use case consists of integrating the different aspects of a digital production, involving disciplines such as automation, digital retrofitting, operational technology, and informational technology. Thus, it provides students with a comprehensive understanding of the benefits and limitations of IIoT.

Development of a Digital Architecture for Distributed CNC Machine Health Monitoring

Abstract With the advancement of the Internet of Things, machines are expected to become more connected by transmitting operational data in ways that can readily be consumed by analytics engines. In recent years, a substantial amount of research has been conducted to create techniques of acquiring and utilizing machine data to inform supply chain decisions and monitor machine health. In modern manufacturing equipment, standard interfaces such as MTConnect and Open Platform Communications–Unified Architecture facilitate the data acquisition process by providing a means of easily capturing machine controller data. With data from these interfaces, monitoring quantities such as machine utilization are possible by monitoring the MTConnect interface and performing analysis on the machine state. In a distributed manufacturing environment, a means of remotely accessing this data must be developed. The infrastructure responsible for this data transmission must be secure, scalable, and standardized. If detailed machine health metrics are to be analyzed, the infrastructure should be able to accommodate data from sources beyond the machine controller itself. Supplementing the controller data with that from additional sensors, such as accelerometers, temperature, humidity, and current sensors, a more complete picture of machine health status can be created. This article will present a digital architecture that meets these criteria and demonstrate the use cases in machine utilization and health monitoring.

An Introduction to OPC UA TSN for Industrial Communication Systems

The industrial communication market is dominated by Ethernet-based fieldbus systems. Although they share similar requirements and market segments, their implementations and ecosystems differ considerably. As a result, end customers and device manufacturers are faced with a multitude of technologies that need to be produced, run, diagnosed, maintained, and kept in stock. Although the availability of products and services is largely satisfactory, dealing with multiple solutions generates high costs and limits IoT capability. This paper introduces Open Platform Communication Unified Architecture Time-Sensitive Networking (OPC UA TSN) as a new technology and presents the current view. This time, the industrial prospects of fulfilling industrial communication requirements while leveraging the cost benefits of standard Ethernet hardware in the midterm are in reach. We anticipate that OPC UA TSN will reveal itself as a game changer in the field of industrial automation, being a candidate for establishing a holistic communication infrastructure from the sensor to the cloud.

Residential Flexibility Management: A Case Study in Distribution Networks

Demand-side flexibility management is a key enabler of the transformation towards the high penetration of renewable energy resources. We present a flexibility-management system called Flex4Grid, which is designed to provide a low-cost solution for residential consumers wishing to participate in power-grid balancing. The Flex4Grid system continuously forecasts the need for flexibility in a power grid and informs consumers about the flexibility-management periods. Consumers can provide their flexibility to an aggregator in exchange for a reward, which depends on the selected incentive scheme. The automation of the flexibility-management events is provided by interfacing with devices and the system via the Z-Wave and open platform communication unified architecture (OPC UA) technologies. The Flex4Grid system has been deployed in three pilots in Slovenia and Germany. A large-scale pilot in Celje, Slovenia, with 1047 participants, was used to collect statistical data regarding how consumers participate in the flexibility-management events. A critical peak-pricing incentive scheme was used in the Celje pilot. The smaller German pilots with a total of 185 participants were used for testing the technical capabilities of the system. User-satisfaction surveys were performed in all three pilots. The results indicate that the proposed approach is appropriate for engaging consumers in flexibility-management events. On average, the pilots' participants reduced their load by 10% during a peak event. The overall scores of the user-satisfaction survey were 3.4 and 3.9 on a 5-point Likert scale for the German and Slovenian pilots, respectively. These are good results for a prototype system; however, improvements to the stability and usability of the system are required.

A Novel CPPS Architecture Integrated with Centralized OPC UA server for 5G-based Smart Manufacturing

The deployment of a Cyber Physical Product System (CPPS) is an important system that must be accompanied in order to build a smart factory. Based on 5G network, it is true that Smart Factories move physical factories to a digital-based cyber world through CPPS and monitor and control them intelligently and autonomously. However, the existing architectures of CPPS present only abstract modeling forms of architecture, and there was a lack of research into applying the OPC UA Framework (Open Platform Communication Unified Architecture), an international standard for data collection and exchange at smart plants, as the basic framework of CPPS. Architecture Configuration This enables the implementation of CPPS, which can include both cloud and IoT, only when field data distributed under a CPPS architecture is collected and centralized on a centralized server. In this study, a CPPS architecture was implemented through a central OPC UA server that applied the technology system to the OPC UA Framework compliant with the Central Processing UA Framework based on the 5G network, and a CPPS architecture, including how the OPC UA modeling process automatically generated CPPS logic and data processing processes, were actually implemented to study its performance and availability.

Design and Implementation of CPPS and Edge Computing Architecture based on OPC UA Server

CPPS (Cyber Physical Production System) must be accompanied to build a smart factory. Through the CPPS, it is the reality of a smart factory to move physical factories to a digital based Cyber world and to monitor and control them intelligently and autonomously. However, the existing CPPS architectures present only an abstract modeling architecture, and the application of the OPC UA (Open Platform Communication Unified Architecture) Framework, which is the international standard for data exchange in smart factories, as the basic system of CPPS. In addition, the construction of CPPS using the cloud is still in its infancy, and a cloud platform accompanied by Edge Computing is needed considering the real-time, unstructured and distributed control of factories. In this paper, we propose an architecture that implements CPPS in the cloud with a cloud CPPS architecture applicable to real factories for smart factories, distributed control using Edge Computing with Container Docker, and an architecture that provides fault tolerance through load balancing and clustering using Edge Orchestration. Some implementations have been tested for availability.

Microgrids platform: A design and implementation of common platform for seamless microgrids operation

One of the main and essential features in microgrids is a reliable and secure communication networks which enable two-way communication between microgrids components and between microgrids to other systems. Microgrids components, as well as the other related system, currently work on different communication standards such as IEC 61850, Common Information Model (CIM), Open Platform Communication-Unified Architecture (OPC-UA), Modbus, and Distributed Network Protocol (DNP3). Therefore, it requires a harmonization system to enable them to communicate each other. This paper presents a development of a common platform for microgrids that provides interoperability between components with different communication standards. This common platform also provides necessary infrastructures to the various business owners who involve in the microgrids system. First, various communication standards used in the microgrids platform are described including the harmonization between particular standards. Then, the development of microgrids platforms including Substation Configuration Language (SCL) studio, SCADA, Integrated Model Harmonization Studio (IMHS), and integrated Gateway is presented. Finally, the conformity of the proposed microgrids platform is verified on IEEE 9-bus network.