In recent years, the digital twin has attracted widespread attention as an important means of digitalization and intelligence. However, the digital twin is becoming more and more complex due to the ...expansion of need on the simulation of multi-scale and multi-scenario in reality. The instance of digital twin in references mostly concentrates a particular application, while it is still a lack of a method for constructing the complex digital twin in the total elements, the variable scale of working environments, changeable process, not even the coupling effects. In this paper, a novel modeling method for such a complex digital twin is proposed based on the standardized processing on the model division and assembly. Firstly, the complex model of digital twin is divided into several simple models according to the composition, context, component, and code in 4C architecture. Composition and context make the digital twin focus on the effective elements in a specific scale and scenario. Component and code develop the digital twin in standard-based modularization. Secondly, assemble the simple models of digital twins into the complex model through information fusion, multi-scale association and multi-scenarios iterations. Ontology establishes the complete information library of the entities on different digital twins. Knowledge graph bridges the structure relationship between the different scales of digital twins. The scenario iterations realize the behavior interaction and the accuracy calculation results. It provides an implementable method to construct a complex model of digital twin, and the reuse of components and code also enables rapid development of digital twins.
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12.
Digital Twin: Where do humans fit in? Agrawal, Ashwin; Thiel, Robert; Jain, Pooja ...
Automation in construction,
April 2023, 2023-04-00, Volume:
148
Journal Article
Peer reviewed
Open access
Digital Twin (DT) technology is far from being comprehensive and mature, resulting in their piecemeal implementation in practice where some functions are automated by DTs, and others are still ...performed by humans. This piecemeal implementation of DTs often leaves practitioners wondering what roles (or functions) to allocate to DTs in a work system, and how might it impact humans. A lack of knowledge about the roles that humans and DTs play in a work system can result in significant costs, misallocation of resources, unrealistic expectations from DTs, and strategic misalignments. To alleviate this challenge, this paper answers the research question: When humans work with DTs, what types of roles can a DT play, and to what extent can those roles be automated? Specifically, we propose a two-dimensional conceptual framework, Levels of Digital Twin (LoDT). The framework is an integration of the types of roles a DT can play, broadly categorized under (1) Observer, (2) Analyst, (3) Decision Maker, and (4) Action Executor, and the extent of automation for each of these roles, divided into five different levels ranging from completely manual to fully automated. A particular DT can play any number of roles at varying levels. The framework can help practitioners systematically plan DT deployments, clearly communicate goals and deliverables, and lay out a strategic vision. A case study illustrates the usefulness of the framework.
•Digital Twin human interaction•Digital Twin can play multiple roles in a work system.•Levels of Digital Twin framework provides a common language for understanding.•Digital Twin must be evaluated for each case – a “one size fits all” does not work.
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Aiming at the difficulties in modelling, simulation and verification in digital twin workshop, a modelling and online training method for digital twin workshop is proposed. This paper describes a ...multi-level digital twin aggregate modelling method, including the status attributes, the static performance attributes and the fluctuation performance attributes, and designs a digital twin organisation system, namely, digital twin graph. According to the data demand for digital twin aggregates, a spatio-temporal data model is constructed. The digital twin model training method using truncated normal distribution is presented. Furthermore, a verification method based on real-virtual error for a digital twin model is proposed. The effectiveness of real-time status monitoring, online model training and simulation for production is verified by a case.
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With the advent of new generation information technologies in industry and product design, the big data-driven product design era has arrived. However, the big data-driven product design mainly ...places emphasis on the analysis of physical data rather than the virtual models, in other words, the convergence between product physical and virtual space is usually absent. Digital twin, a new emerging and fast growing technology which connects the physical and virtual world, has attracted much attention worldwide recently. This paper presents a new method for product design based on the digital twin approach. The development of product design is briefly introduced first. The framework of digital twin-driven product design (DTPD) is then proposed and analysed. A case is presented to illustrate the application of the proposed DTPD method.
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This paper reviews the current status and advancement of Digital Twin-driven smart manufacturing, with highlights on the following aspects:•Presented the connotation of Digital Twin-driven smart ...manufacturing and its potential impacts.•Proposed a reference model for constructing a Digital Twin, comprising of an information model, data processing and industrial communication technologies.•Discussed seven crucial research issues for developing Digital Twin applications for smart manufacturing.
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.
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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.
Digital Twin is one of the promising digital technologies being developed at present to support digital transformation and decision making in multiple industries. While the concept of a Digital Twin ...is nearly 20 years old, it continues to evolve as it expands to new industries and use cases. This has resulted in a continually increasing variety of definitions that threatens to dilute the concept and lead to ineffective implementations of the technology. There is a need for a consolidated and generalized definition, with clearly established characteristics to distinguish what constitutes a Digital Twin and what does not. This paper reviews 46 Digital Twin definitions given in the literature over the past ten years to propose a generalized definition that encompasses the breadth of options available and provides a detailed characterization which includes criteria to distinguish the Digital Twin from other digital technologies. Next, a process and considerations for the implementation of Digital Twins is presented through a case study. Digital Twin future needs and opportunities are also outlined.
•Definitions of a Digital Twin can be characterized by three primary components.•Digital Twins can be distinguished from other digital modeling and simulation.•Successful Digital Twin scoping based on set outcomes and principle of parsimony.
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More and more organizations recognize the need for digitalization. An essential concept in this context is the Digital Twin (DT). At its core, a DT is a virtual representation of physical reality and ...the associated data exchange. Despite its relevance, practice shows that the application of true DTs is relatively low. Often benefits are intangible and costs are perceived as too high. One of the critical factors affecting benefits, defined as the difference of savings potential and costs, is fidelity. The DT fidelity defines how precisely the virtual representation mirrors its physical reality. Contrary to what most definitions suggest, an optimum fidelity exists where the net benefit is maximized. However, there is a lack of methods that support in conceptualizing DTs with optimum fidelity in manufacturing organizations. Elaborating on suitable fidelity levels is a subjective process dependent on the experience of DT developers. Consequently, the Digital Twin Fidelity Calculation Model (DT-FCM) was developed in this article using Design Science Research. The DT-FCM provides a novel approach to enable the calculation of the optimum DT fidelity based on a specific objective. As a crucial part of the DT design cycle, DT-FCM integrates seamlessly with existing models. The DT-FCM provides a systematic approach that increases the probability of success with the application of DTs.
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•The Digital Twin Object (DTO) is defined to achieve the model's goal of standardization, modularity, and ease of configuration.•The General Construction Process obviates the need for repetitive ...machine model assembly and coding of basic functions.•The Rapid mounting and communication configuration mechanism decouples data storage, information analysis, and communication configuration in the DTO.
A large-scale manufacturing workshop includes a wide variety and a large amount of equipment. When equipment is mapped as a digital twin (DT) model, the DT model has complex and implicit or non-hierarchical relationships, which makes the development of a DT workshop system (DTWS) for a manufacturing plant challenging. To address this problem, this paper proposes a rapid construction method of equipment model (RCMEM) for a discrete manufacturing DT workshop system, which can meet the requirements of complex manufacturing business scenarios, improve the efficiency and quality of the DT model construction at the equipment level, and form an efficient equipment model construction method. First, a DT object (DTO), which represents a basic unit of the DT model, is defined. The DTO is used to derive the DT model at the equipment level. The DTO collects and wraps generalization-capable functions from equipment into components, and geometric, functional, and communicative descriptions are combined into a single model. The DT model can increase the scalability, reusability, and modeling quality by reusing the DTO capabilities. Further, a general construction process of the DTO model of multi-axis computer numerical control (CNC) machines is presented. This process standardizes the common capabilities of the equipment models and minimizes the construction time of machines’ DT models. Furthermore, a rapid mounting and communication configuration mechanism (RMCCM) is proposed. This mechanism enables fast DTO network communication and improves interoperability in a multi-source data environment. This paper also proposes a DTWorks Software development kit, which can help developers to build digital factory standalone applications. The RCMEM is implemented into the DTWorks. Finally, a real DTWS case is used to examine the differences in equipment model building before and after the application of the RCMEM. The results demonstrate the good effectiveness of the RCMEM in complex business settings.
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•A hybrid predictive maintenance method for CNC machine tools driven by Digital Twin model and Digital Twin data is proposed.•Digital Twin model is built in multi-domain and reflects the actual ...working conditions; Digital Twin data is gathered by different types of sensors and used for data-driven remaining useful life prediction model; then the system observation value and theoretical derivation value are fused by particle filtering algorithm. The validity and accuracy of the proposed method are verified by cutting tool life prediction of CNC machine tools.•This method enables the Digital Twin model and data to be better integrated and applied, thus can give out a more accurate and intelligent result than before.
As a typical manufacturing equipment, CNC machine tool (CNCMT) is the mother machine of industry. Fault of CNCMT might cause the loss of precision and affect the production if troubleshooting is not timely. Therefore, the reliability of CNCMT has a big significance. Predictive maintenance is an effective method to avoid faults and casualties. Due to less consideration of the status variety and consistency of CNCMT in its life cycle, current methods cannot achieve accurate, timely and intelligent results. To realize reliable predictive maintenance of CNCMT, a hybrid approach driven by Digital Twin (DT) is studied. This approach is DT model-based and DT data-driven hybrid. With the proposed framework, a hybrid predictive maintenance algorithm based on DT model and DT data is researched. At last, a case study on cutting tool life prediction is conducted. The result shows that the proposed method is feasible and more accurate than single approach.
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