OEM&Lieferant Ausgabe 2/2018 / OEM&Supplier Edition 2/2018

Industry 4.0 128 Currently digital twins are discussed in Industry 4.0-working groups when talking about the asset administration shell [2] or industry 4.0- components. From our point of view, the digital twin will become a major topic for research in the coming years, because digital twins are not single objects or monolithic data models, but are comprised of different aspects of digital representations, functionalities, models, inter- faces etc. From a manufacturing and its engin- eering perspective, it is evident that digital twins require and cover different types of as- pects, such as Self-description using unique attributes and parameters describing configuration data, e.g. for auto-identification, to connect ma- chines and components easily to MES and other Industrial IoT-solutions [3] . Description of skills, including parts of con- trol code leading to the result that an as- sembly of components and their respective parts of control logic fit to finally running control program. This leads to a PLUGand- WORK, allowing for plugging in new com- ponents at runtime, and integrating them automatically on a functional level [4] . Models of the correct runtime behavior of a machine, a line or an entire manufacturing shop, based on learned data from machine learning. Offline and online simulation including the very different types of simulation such as fi- nite element simulation, virtual commission- ing or physics simulation in which produced goods interact with machine kinematics. Ideally, different simulation models must be able to interact to come to an integrated simulation model. Up to now, the digital twin has been used especially in the context of simulation; as we point out here, this definition is much too narrow. Digital factory describing machines and other manufacturing resources, buildings and utilities. Building information model (BIM) might also be part of a digital twin as long as it contains relevant information, e.g. topology. The concept of digital factories al- ready has a long history and is described by well-known standards, such as VDI 4499. Services that a cyber-physical component offers to its users. IT security, access rights, handling of certifi- cates, version management and compatibil- ity checks of different versions of digital twins [5] . For Industry 4.0 and the digitization of manu- facturing digital twins are essential. Their con- tent must be used through different stages of the lifecycle, within different types of platforms and various tools, from engineering to after sales services. The following use cases already show the potential benefits, e.g. to optimize products and processes almost during runtime: 1. Automation supplier WAGO has developed an approach called DIMA (decentralized in- telligence for modular equipment), enabling modules from different vendors to be inte- grated to a final production system. Its core is the Module Type Package (MTP), a kind of self-description of the modules. The MTP can be accessed through an interface and contains communication parameters, func- tional production services that the module The Digital Twin – an essential key technology for Industry 4.0 By Dr. Olaf Sauer, Fraunhofer IOSB Currently the Digital Twin (see figure 1) is one of the emerging technologies under discussion in several domains; it is a concept of modelling assets with all geometrical data, kinematic functionality and logical behavior using digital tools. The digital twin refers directly to the physical asset and allows simulating, controlling and improving it. Accord- ing to Gartner today less than 1% of the physical machines and components “are modeled such that the models capture and mimic behavior” [1] . Image: © Fraunhofer IOSB / Graphic: © 2017 Gartner, Inc. Hype Cycle for Emerging Technologies 2017