Digital Twin (DT) is a core concept in the digitalization process in the Industry 4.0 and upcoming innovations such as Industry 5.0 and Metaverse. This digitalization can result in a huge amount of data that has not been collected before and now can help to understand and optimize processes and products. However, an important challenge is to really understand what the data can mean and then find out new information and knowledge that can be used for further optimizations. Therefore, it is important to have the virtual representations that the DT proposes as close as possible to the real-world application in a way that it can be understood in the same way by different people and systems. In this context, semantics annotations can be used to organize data by inserting knowledge into the model and providing a common understanding of a specific concept. This paper proposes a methodology for creating semantic digital twin models using the well-known tool called Node-RED. A sequence of steps is described that covers data acquisition, semantics annotations to this incoming data, assets modeling with their relationships which generates a graph of nodes and connections that is saved into a graph database. To be able to realize such a model, 7 so-called nodes have been developed for Node-RED. Finally, a use case has been implemented to demonstrate the application of the proposed methodology.

─Smart City is one area of application for the Internet of Things (IoT) and it has been attracting attention from both academia and industry. Cities will be composed by autonomous parts that communicate and provide services to each other. For instance, cars (autonomous or not) may be seen as a service that transports people from one point to another. Interactions between users and these kinds of services will grow, making it necessary to have digitization of all these parts of the Smart City. The Digital Twin (DT) concept proposes that real-world assets have a virtual representation connecting the physical world with the cyber world. This allows to track the whole life-cycle of this object as well as perform simulations with current or previously stored data. In this context, this work proposes the use of Digital Twin for enabling and supporting car-as-a-service (CaaS). A case study has been developed to demonstrate the modeling and the deployment of the Digital Twin, highlighting how this concept can be one of the key enablers for CaaS.

The digital twin (DT) is a virtual representation of a physical object, which has been proposed as one of the key concepts for Industry 4.0. The DT provides a virtual representation of products along their lifecycle that enables the prediction and optimization of the behavior of a production system and its components. A methodology design using model-driven engineering (MDE) is proposed that strives toward being both flexible and generic. This approach is presented at two levels: first, a DT is modeled as a composition of basic components that provide basic functionalities, such as identification, storage, communication, security, data management, human-machine interface (HMI), and simulation; second, an aggregated DT is defined as a hierarchical composition of other DTs. A generic reference architecture based on these concepts and a concrete implementation methodology are proposed using AutomationML. This methodology follows an MDE approach that supports most of the DT features currently proposed in the literature. A case study has been developed, the proposed ideas are being evaluated with industrial case studies, and some of the preliminary results are described in this article. With the case study, it is possible to verify that the proposed methodology supports the creation and the deployment process of a DT.

When developing Real-Time and Embedded Systems (RTES), different types of constraints should be considered in specification, modeling, architectural design and system implementation. In most cases, these constraints describe timing, precedence or resource restriction. Correct description and evaluation of these complex information along of RTES design are directly related to their reliability, safety and quality. In this research, a methodology to describe real-time and embedded information in requirements, functional, logical and technical viewpoints is briefly presented, as well as an approach to analyze the annotated constraints. MARTE constraints have been consistently applied in designing models and implemented at lower abstraction models. Here, pseudo automated generation of timing, precedence and resources constraints is performed from the graphical models to the final source code models. Therefore, the proposed approach has a great value to RTES design once it has traced constraints along of the architectural design and it also presents a manner to check if constraints are being reached in accordance with early design description.

Architectural design of Real-Time and Embedded Systems must describe the system components (software and hardware) in a common and comprehensible manner to be understandable to several stakeholders involved in the development process. This article explores the combined adoption of a well-recognized methodology to activities of architectural system design, with the MARTE profile, considering non-functional annotations in model elements. The proposed approach aims to define a general and appropriate architectural viewpoint to the real-time and embedded domain. MARTE profile and SPES methodology are employed in modeling strategies in order to explore the requirements, services and systems components. In this paper, a case study in the automotive system domain is performed and the architectural viewpoints are able to represent functional and non-functional requirements, performance and temporal restrictions in the field of automotive systems at different levels of detail and abstraction.

Development of Real-Time and Embedded Systems (RTES) involves a number of complex activities performed by a diversity of stakeholders. In most cases, RTES requires a number of different physical and logical components with numerous functional and non-functional constraints. Therefore, it is essential to ensure the representation, specification and analysis of quality activities of these systems since the early design activities. SPES (Software Platform Embedded Systems) methodology has been considered to describe a framework to develop RTES, but it does not specify directly how and which modeling languages should be adopted. Thus, this research adopts SPES guidelines and applies SysML and MARTE profiles to create models in the architectural viewpoints, while it highlights functional properties and different non-functional constraints of the system. A formalization of design viewpoints is presented in order to contribute to quantitative measurement to describe an analysis of the design complexity since the initial design activities. As contributions of this paper, it can be highlighted a proposal to formalize the RTES design activities (viewpoints), a measurement of the system design complexity since the initial design activities (in accordance with the design activities) and, also, the definition of a formalized manner to analyse RTES complexity without the interference of user external knowledge.

Faults in industrial communication protocols represent an important problem for industrial systems as they may lead to severe losses. Observing the need for approaches to deal with this type of problem, this paper studies reliability aspects related to industrial communication protocols and the modeling of possible communication faults. The work proposes a requirements specification based on aspect-oriented concepts to map and model common faults in design phases of embedded systems. A model integrating fault modeling in communication protocols extending the Real-Time From Requirements to Design using Aspects (RT-FRIDA) framework is presented. A case study on vehicular networks was conducted considering the nonfunctional requirements specification of an Active Suspension System. Then, a sequence of fault requirements based in recent studies is modeled and presented to validate the proposed approach. The main contribution of this work is to enable the use of fault modeling in communication protocols and aspect-oriented modeling techniques to mitigate the fault impact in the timing behavior of critical tasks. This study indicates the use of observers' technique modeled to fault diagnosis, so that they can be aggregated into a real-time control system.

The Internet of Things concept is increasingly being used in projects from different areas. Often, projects encompass applications from different domains that need to share information for a common purpose. These types of systems can become complex because they involve different domains and it can be difficult to share information without misinterpreting certain information. Ontologies can be a way to describe information to be shared between different domains. The present work aims to propose a tool that facilitates the creation of Internet of Things systems using ontologies and through this model generate code automatically to pre-automate the integration of devices. A tool has been developed that facilitates the extraction of information from the ontology and it has been validated in the case study.

As the number of network connected devices in an industrial system increases, the management and handling of all the information generated become a challenge. In this work we explore concepts of Cyber-Physical System model the virtual part of industrial devices (sensor, machines, CLPs) using the Digital Twin concept and propose an architecture based on web services for accessing their data. We present a case study where an Augmented Reality system access the Twin Model data via web services and display real-time information to the user. Moreover, we present a review of how the involved concepts, which have a strong computational background, relate to industrial applications and how they can expand the possibility of services and business models.

The gist of the paper is to demonstrate that the economical utilization of the country`s energy supply requires generating electric power wherever hydraulic or fuel energy is available, and collecting the power electrically, just as it is distributed electrically. In the first section a short review of the country`s energy supply in fuel and water power is given, and it is shown that the total potential hydraulic energy of the country is about equal to the total utilized fuel energy. In the second section it is shown that the modern synchronous station is necessary for large hydraulic powers, but the solution of the problem of the economic development of the far more numerous smaller water powers is the adoption of the induction generator. However, the simplicity of the induction generator station results from the relegation of all the functions of excitation, regulation, and control to the main synchronous station. The economic advantage of the induction generator station is that its simplicity permits elimination of most of the hydraulic development by using, instead of one large synchronous station, a number of induction generator stations and collecting their power electrically. The third section considers the characteristics of the induction generator and themore » induction-generator station, and its method of operation, and discusses the condition of ``dropping out of step of the induction generator`` and its avoidance. In the appendix the corresponding problem is pointed out with reference to fuel power, showing that many millions of kilowatts of potential power are wasted by burning fuel and thereby degrading its energy, that could be recovered by interposing simple steam turbine induction generators between the boiler and the steam heating systems, and collecting their power electrically.« less