Title Participants Abstract "From Virtual Sensing to Executable Digital Twin: Towards Multi-objective, Real-time Estimation Algorithms for Vehicle Dynamics through a Digital Twin Approach" "Thijs Devos" "Driven by the digital revolution towards an industry 4.0 context, mechatronic industries such as the automotive sector have undergone major transformations in order to strengthen their flexibility and competitiveness on the market by enhancing vehicle performance and comfort. In addition, safety regulations are becoming increasingly stringent as car accidents happen evermore often due to the rise in population density, especially within large cities. All these aspects pose additional challenges towards the development of new vehicles, corresponding subsystems and control algorithms in order to increase performance, comfort, and safety, which usually presents a trade-off. This has led, amongst others, to the development of Advanced Driving Assistance Systems (ADAS) to enhance passenger vehicle safety, comfort, and performance. To further increase market flexibility and reduce vehicle development costs, Original Equipment Manufacturers (OEMs) are heavily investigating the capabilities of digital twins or virtual representations of physical assets. The idea has already been launched at the end of the 20th century, although thus far practical realizations are still lacking due to the challenging effort needed to synchronize available models and data with the physical asset. Therefore, one of the main goals of this research is to develop a practical realization of a digital twin framework in order to show the potential of virtual assets to reduce development costs and increase market flexibility. In order to achieve this, current state-of-the-art approaches related to vehicle dynamics modeling and virtual sensing must be improved, and novel parameter synchronization strategies have to be developed to ensure that virtual representations are sufficiently accurate. It should be noted that, although the framework was specifically developed for the automotive industry, the general principles are applicable to other sectors as well since this work adopts a physics-based approach. The digital twin as developed in this work is based on three main building blocks, namely (i) a family of vehicle dynamics models, (ii) a range of virtual sensing methodologies allowing communication between virtual models and the physical asset, and (iii) a parameter synchronization tool which provides up-to-date parameters between different models through a general synchronization strategy. Since different applications will require different model complexity, a modeling framework is developed which uses the general theory of classical mechanics to derive equations of motion and consequently provides various solving strategies depending on the complexity of the derived equations. Using this framework, a family of vehicle models is created with the application towards low-velocity driving scenarios and state estimation algorithms in mind. Furthermore, a virtual sensing framework is proposed, which includes an extensive observability analysis in combination with dynamic coupling analysis and a novel sensor selection methodology to allow communication between virtual models and the physical asset. Through the use of a Singular Value Decomposition (SVD), this work shows it is possible to identify unobservable states and to stabilize the estimator Ricatti equation using an observable transformation on the covariance equations, if and only if the targeted quantities of interest are independent from decoupled internal model states. This allows further increasing model complexity without having to increase the amount of required sensors for full observability. Last but not least, a novel sensor selection algorithm was developed which is capable of taking previous observability considerations into account. The selection methodology ranks the possible sensors according to their relative contribution to the targeted quantity of interest estimation performance, characterized by corresponding covariances as calculated by the Extended Kalman Filter (EKF). This approach is capable of handling different sensor types, alternative sensor locations, and sensor accuracy as indicated by their corresponding noise level, which is heavily linked to the associated cost. The combined result of this work is the practical realization of such a digital twin framework for vehicle dynamics applications aiming for the development of real-time estimation algorithms, validated on an internally built demonstration platform, dubbed as the LMSD Concept Car. The estimation methodologies were experimentally validated on several test vehicles including an electric Range Rover Evoque, a Ferrari 250LM, a Goodyear SightLine test vehicle, and the LMSD Concept Car platform. The latter vehicle platform was used to prove that real-time applicability of estimation schemes featuring reduced-complexity models is possible and provides accurate estimation results. Additionally, the work shows that the virtual asset is a powerful tool, enabling various non-trivial analyses using parts of the digital twin to evaluate different vehicle dynamics aspects such as design changes, new controller designs, different powertrain layouts, flexible coupling between subsystems and/or vehicle components and many more." "Critical appraisal of using digital human model, virtual human, human digital twin and digital twin" "Steven Truijen" "This paper addresses the need to define and discuss the relationship between the digital human model, the human digital twin and the digital twin. Nowadays, in scientific literature, the new terms human digital twin or digital twin are mentioned in different fields of applications, omitting the concept digital human model. However, a model is not the same as a twin. Simultaneously, the question of whether a digital human model can be a digital twin and what the relationships are between a digital twin and vice versa arises. Or how do the terms virtual humans, human digital twins, and digital human models interact? Is there a distinction between virtual and digital human models? All these questions are discussed and evaluated in this critical appraisal based on scientific literature research." "Relay selection in Bluetooth Mesh networks by embedding genetic algorithms in a Digital Communication Twin" "Jorg Wieme, Mathias Baert, Jeroen Hoebeke" "Bluetooth Mesh (BM) technology is a suitable candidate to realize mesh networks leveraging on a mains-powered backbone. However, the flooding-based technology requires additional management in order to operate efficiently. Consequently, it offers a diverse set of configuration options to control network behavior, including the selection of relays in the backbone that rebroadcast packets further into the network. In the past, Digital Twin technology has been applied to design a Digital Communication Twin (DCT) of a BM network. The DCT (or Digital Twin Network, DTN) can be used to find an optimal network configuration for given application requirements. This includes a relay selection approach that finds a set of relays to assure sufficient path redundancy in the network. However, existing results prove that this approach can be improved in terms of computation time, flexibility and validity of the proposed set of relays. In this paper, we present a reinterpreted version of a genetic algorithm to tackle this issue. The results show it achieves better results on all three improvement targets, compared to the original approach. Furthermore, it showcases the flexibility and adaptability of the DCT whilst adequately improving the relay selection approach." "Towards an ontology-driven approach for digital twin enabled governed IT management" "Henderik A. Proper, Dominik Bork, Geert Poels" "The Digital Transformation of our society requires IT infrastructures to be more agile, more adaptive, and more connected than ever. At the same time, the owners of such infrastructures are confronted with an increase in regulatory pressure (e.g., the GDPR). These develop-ments put a lot of stress on IT management and governance. To enable IT management and governance to better deal with these challenges, we propose to digitally transform IT governance and management itself by using a Digital Twin based approach. In line with this, we aim to create on ontology-driven Digital Twin for Governed IT Management (DT4GITM) framework. The goal of this framework is to act as a reference architecture for a Digital Twin based infrastructure that connects three interrelated systems: the IT governance processes, the governed IT management processes, and the managed organizational IT assets. The core of the framework involves a generic Governed IT Management (GITM) Domain Ontology, which is planned to be operationalized by a Knowledge Graph based approach that realizes an integrated view on the heterogenous data streams originating from the IT governance and man- agement processes, and the managed IT assets. In this paper, we start by outlining the planned DT4GITM framework and the pivotal role of the GITM Domain Ontology within this. We then elaborate our incremental, and scenario-/case-driven strategy towards the development of the framework as a whole, and the GITM Domain Ontology in particular. This is followed by the elaboration of a specific DT4GITM scenario which serves as a first proof of principle." "A Real-time Physics Based Digital Twin for Online MOSFET Condition Monitoring in PV Converter Applications" "Leander VAN CAPPELLEN, Martijn Deckers, Omid ALAVI, Michael DAENEN, Johan Driesen" "This article proposes a fast, lightweight and physics-based digital twin to estimate the real-time junction, case and heat sink temperatures of the switching device in a photovoltaic (PV) boost converter. A lookup table approach is used to model the electric behavior while a traditional Cauer approach is used for the thermal model. To extract the thermal resistances of the MOSFET layers and convection, a finite element method (FEM) simulation is performed. To validate the digital twin, a physical replica of the boost converter is built and a real mission profile is applied. The resulting heat sink temperature profile has a mean average error of 0.8 degrees C with an increase in error at higher temperatures. In future work this twin will be used to separate the effect of temperature and degradation on the on resistance of the MOSFET to monitor degradation during operation." "Advanced Digital Twin Framework for Electric Truck" "Duong Tran Phuoc, Leo Xenakis, Shantanu Pardhi, Iban Vicente Makazaga, Michael Glensvig, Hans Michael Koegeler, Robinson Medina, Steven Wilkins, Omar Hegazy" "This paper introduces an advanced digital twin (DT) framework for electric truck, which consists of a universal multi-layer DT architecture and multi-disciplinary AVL software suites. The proposed DT framework can realize all functionalities conducted within key spaces in a generic DT concept: physical space, communication channel for data fusion, and digital twin space. A workflow and a management platform are introduced to generate, operate, calibrate, and run DTs. Furthermore, a pre-DT model of energy consumption estimation is developed based on a longitudinal model, to evaluate the conceptual designs during early design stage. The holistic digital twin framework enables support at the industrial level of new fully integrated architectures and designs for electric truck applications in a European project named NextETRUCK. Original equipment manufacturers (OEMs) and tier-one suppliers will be able to push beyond the investigation of another generation of efficient and affordable electric trucks." "The Digital Twin concept and its role in reducing uncertainty in synchromodal transport" "Tomas Ambra, Cathy Macharis, An Caris" "Transparency and information exchange are important parts of synchromodality that contribute to better overview of options when tackling delays, dynamic switching, and handling of unexpected events that affect delivery lead-times and costs. The most challenging aspect when making decisions in a complex adaptive dynamic system, is the ever-changing environment as we introduce more flexibility which may lead to more unpredictable outcomes. This paper presents 2 simple illustrative cases to asses different transparency levels and the adaptive behavior of assets; 1) a static case where assets do not have the ability to respond proactively to disruptive events, and 2) a dynamic case where assets have the ability to query their environmental context and exchange information. The severity of the events is captured by probability distribution functions by deploying Monte Carlo simulations to showcase the potential benefits of the Digital Twin concept in a synchromodal context. The links between current Digital Twin applications and synchromodal transport are discussed in order to spark a new wave of reducing uncertainties in dynamic environments. Lastly, the paper sheds more light on how to connect closed virtual simulations with the real physical system." "TEMPERATURE DISTRIBUTION DETERMINATION OF THERMOPLASTIC COMPOSITES SAMPLES IN BIAS EXTENSION TESTS USING A DIGITAL TWIN" "Ramak Hossein Abadi" "Designing a production process such as thermoforming for thermoplastic composites might be challenging as it requires material characteristics at high temperatures. Material characterization tests (e.g., bias extension) in the molten state can encounter several difficulties, one of the most important ones is maintaining a uniform temperature distribution on the sample. Accordingly, during this research, a set of thermal tests has been initially done at different temperature levels. During these tests, the temperature was measured at several locations. Next, we developed a finite element model for both the sample and the clamp. In the final step, the boundary conditions of the FE model have been determined by coupling the experimental results and the numerical model. Results show the strong dependency of the sample temperature gradient on the clamps, which has been ignored in the previous studies. Moreover, a sensitivity study is done to select the best location for the temperature sensor for future studies." "Digital twin of a laser line scanner: uncertainty evaluation and scan path planning" "Michiel Vlaeyen" "According to the Guide of the Expression of Uncertainty in Measurement every measurement needs to be accompanied with an uncertainty. A digital twin of a measurement system can be used to determine the measurement uncertainty through Monte Carlo simulations. In the past, the state of the art has developed virtual coordinate measuring machines to determine the measurement uncertainty. However, this research was never fully extended towards a digital twin of an optical measurement system. One of the main reasons is the high number of different error contributors inherent to non‑contact probing. The goal of a digital twin is to mimic its physical counterpart. Therefore, the first objective of this thesis is the development of a digital twin of a laser line scanner mounted on a coordinate measuring machine. The considered error contributors are relevant for the measurement conditions in which this research is performed, namely a metrology laboratory. In order to accomplish the first objective, an equation to model the systematic error and the random error of the laser line scanner is formulated. This equation is a second degree polynomial function with variables dependent on the relative position and orientation of the probing system towards the object. The coefficients of the model are experimentally determined. The developed method is reproducible with the standard equipment available in a metrology laboratory. The proposed model and the incorporation of the constraints of a laser line scanner allow to simulate the probing device. Furthermore, an updated method of virtual coordinate measuring machine is proposed. This is essential for the digital twin, since the laser line scanner is positioned and oriented by a coordinate measuring machine. The introduced virtual coordinate measuring machine distinguishes itself from the state of the art by its clear description of the representation of the incorporated errors. The kinematic errors of the model are elaborated with a new‑defined equation. The combination of the virtual coordinate measuring machine and the model of the laser line scanner form the digital twin. The obtained results are validated through a series of experimental measurements in the metrology laboratory. The second objective is to determine the task‑specific measurement uncertainty, when measuring with a laser line scanner. The in‑house developed digital twin allows to perform measurements virtually, thus the measurands are virtually determined. As a consequence a variety of geometrical properties, with a known nominal value, can be scrutinized. Different measurement strategies are applied to measure a feature, in order to investigate the influence on the uncertainty budget. As validation the virtually obtained conclusions are compared with the experimentally obtained data. The third objective is to determine the scan path of the laser line scanner autonomously. The manufacturing industry tends to manufacture an increased amount of lot‑size‑one products with small tolerances. As a result of this tendency, the quality inspections become a bottleneck in the manufacturing process. Optical probes are able to reduce the measurement time compared to conventional tactile measurements. Digital twins allow to estimate the uncertainty offline without the need of repeated online measurements. However, the manual determination of the scan path is time‑consuming and is detrimental for the traceability of the measurement. The scan path generation for complex geometries is challenging, hence, the third objective was formulated. The proposed algorithm to determine the scan path autonomously takes the uncertainty budget of toleranced features and all the constraints of the measurement system into account. Making this task autonomously reduces the inspection time and allows the transition of the measurement system towards the Industry 4.0. The validation of the proposed algorithm is performed on two objects. The algorithm was able to autonomously generate a scan path which is able to cover the entire measurable surface and to determine the measurement uncertainty." "Digital twin driven intelligent systems and emerging metaverse" "This book covers the notion of the digital twin, which has the potential to alter the way systems are governed and manufactured. It also addresses the metaverse as an emerging technology with its roots in literature, cross-platform avatars, and artificial intelligence-oriented cybersecurity issues. The untapped potential of the metaverse and digital twins as enabling technologies for the next-generation industries is emphasized in various chapters. Digital twin technology enables manufacturers to comprehend their products throughout product design better, integrate simulation, tracking, and optimization in real-time, and appropriately analyze operations. Especially for complicated products or systems, testing on a digital twin is more efficient (more accessible, quicker, less error-prone, and less expensive). The product is examined in its virtual version before it is displayed in the actual world. Additionally, the digital twin minimizes operational expenses and increases the longevity of equipment and assets. By prolonging the life of the thing, they represent and enhance its working efficiency; it may minimize operating costs and prospective capital spending. The digital twin idea is becoming a reality as it has begun to be used in several industries, including energy, manufacturing, construction, transportation, aerospace, smart cities, healthcare, cyber security, finance, and agriculture. Academic and industrial experts highlighted the most compelling use cases of digital twins and metaverses and the challenges inherent in their implementation. Readers who want to make more effective systems will find the book useful. Also, people who want to get an idea and vision of how technology will change our lives will benefit from this book."