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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Nutzerzentrierte Entwicklung einer ortsunabhängigen Maschinenabnahme mittels Augmented Reality

Kovacevic, Nedim, Meinzer, Jantje, Stark, Rainer 06 September 2021 (has links)
Die Nutzung von Augmented Reality (AR) stellt eine Vielzahl von Lösungsansätzen für Herausforderungen unterschiedlicher Bereiche, z.B. der Industrie, Medizin, Unterhaltungsmedien und Bildung, zur Verfügung. Speziell werden hier die Möglichkeiten von AR in der Fertigungsindustrie, genauer bei der Abnahme elektrischer Antriebe der Siemens AG, betrachtet. Dabei werden unter anderem messbare Größen wie Drehmoment, Ankerstrom, -spannung, Drehzahl, Schwingungen, Fertigungstoleranzen etc. gemessen, aber auch nicht quantifizierbare Größen wie Sichtprüfungen von Schweißnähten und Lackierung in Betracht gezogen. Angestrebt wird eine Methode, welche es zukünftig ermöglicht, die Inbetriebnahme ortsunabhängig zu verfolgen und Inspektionen aus der Ferne durchzuführen. Die Herausforderung liegt dabei darin, eine zumindest gleichwertige, wenn nicht sogar verbesserte Erfahrung und Prüfergebnisvalidität für die Beteiligten gegenüber der vor Ort Abnahme zu erzeugen. Im Rahmen des Forschungsvorhabens wurde in interdisziplinärer Zusammenarbeit zwischen Ingenieur/-innen und Sozialwissenschaftler/-innen ein Demonstrator-Konzept für eine ortsunabhängige Maschinenabnahme entwickelt.
142

Návrh digitálního dvojčete CNC obráběcího stroje / Design of digital twinn of CNC machine tool

Staněk, Václav January 2019 (has links)
The Master’s thesis deals with design of digital twins of machine tools and application of designed procedure on a case study – digital twin of the machine tool MCV 754 Quick. In the first part are described current roles of digital twins in the field of machine tools and also hardware and software options for creating them. Software and hardware tools by Siemens (Mechatronics Concept Designer and SIMIT) are used for the case study. The complex procedure of creating the digital twin is designed in the second part, starting with preparation of a model, ending with the virtual commissioning of the machine tool MCV 754 Quick. The procedure is described in detail, including preparation of 3D model of the machine tool, assignment of physical properties and joints, preparation of PLC, connection all the elements of the whole system: Sinumerik – SIMIT – Mechatronics Concept Designer and controlling the twin via CNC automation system. Output of the thesis is the virtually commissioned machine tool, capable of being controlled by Sinumerik 840D sl. This is the first step in development of the full-fledged digital twin of machine tool, which can be used for testing the functionality and capability of this new technology in industry.
143

Medicinsk digital tvilling : Den digitala människokroppen / Medical digital twin : The digital human body

Gustafsson, Ted, Rajala, Lukas, Nee, Lukas, Nordin, Herman, Nimhed, Carl, Bahnan, Gabraiel, Almrot, Jacob, Stålebrink, Lovisa January 2020 (has links)
Den här rapporten behandlar ett projekt utfört i kandidatkursen TDDD96 - Kandidatprojekt i programvaruutveckling. Projektet är utfört av åtta studenter från datateknik- ochmjukvaruteknikprogrammen på Linköpings universitet (LiU) för kunden från institutionen för medicinsk teknik (IMT) på LiU. Syftet med projektet var att ta fram en prototypmed ett grafiskt gränssnitt för uppvisning och simulering av hur kroppen påverkas av t.ex.träning, sömn och kostintag. Modellerna som simulerats är framtagna av forskningsgrup-pen integrativ system biologi för institutionen för medicinsk teknik LiU och resultatet är i form av dataändringar och grafer i programmets gränssnit.
144

Digital Twin-based Intrusion Detection for Industrial Control Systems

Varghese, Seba January 2021 (has links)
Digital twins for industrial control systems have gained significant interest over recent years. This attention is mainly because of the advanced capabilities offered by digital twins in the areas of simulation, optimization, and predictive maintenance. Some recent studies discuss the possibility of using digital twins for intrusion detection in industrial control systems. To this end, this thesis aims to propose a security framework for industrial control systems including its digital twin for security monitoring and a machine learning-based intrusion detection system for real-time intrusion detection. The digital twin solution used in this study is a standalone simulation of an industrial filling plant available as open-source. After thoroughly evaluating the implementation aspects of the existing knowledge-driven open-source digital twin solutions of industrial control systems, this solution is chosen. The cybersecurity analysis approach utilizes this digital twin to model and execute different realistic process-aware attack scenarios and generate a training dataset reflecting the process measurements under normal operations and attack scenarios. A total of 23 attack scenarios are modelled and executed in the digital twin and these scenarios belong to four different attack types, naming command injection, network DoS, calculated measurement injection, and naive measurement injection. Furthermore, the proposed framework also includes a machine learning-based intrusion detection system. This intrusion detection system is designed in two stages. The first stage involves an offline evaluation of the performance of eight different supervised machine learning algorithms on the labelled dataset. In the second stage, a stacked ensemble classifier model that combines the best performing supervised algorithms on different training dataset labels is modelled as the final machine learning model. This stacked ensemble model is trained offline using the labelled dataset and then used for classifying the incoming data samples from the digital twin during the live operation of the system. The results show that the designed intrusion detection system is capable of detecting and classifying intrusions in near real-time (0.1 seconds). The practicality and benefits of the proposed digital twin-based security framework are also discussed in this work. / Digitala tvillingar för industriella styrsystem har fått ett betydande intresse under de senaste åren. Denna uppmärksamhet beror främst på de avancerade möjligheter som digitala tvillingar erbjuder inom simulering, optimering och förutsägbart underhåll. Några färska studier diskuterar möjligheten att använda digitala tvillingar för intrångsdetektering i industriella styrsystem. För detta ändamål syftar denna avhandling till att föreslå ett säkerhetsramverk för industriella styrsystem inklusive dess digitala tvilling för säkerhetsövervakning och ett maskininlärningsbaserat intrångsdetekteringssystem för intrångsdetektering i realtid. Den digitala tvillinglösningen som används i denna studie är en fristående simulering av en industriell fyllningsanläggning som finns tillgänglig som öppen källkod. Efter noggrann utvärdering av implementeringsaspekterna för de befintliga kunskapsdrivna digitala tvillinglösningarna med öppen källkod för industriella styrsystem, väljs denna lösning. Cybersäkerhetsanalysmetoden använder denna digitala tvilling för att modellera och exekvera olika realistiska processmedvetna attackscenarier och generera en utbildningsdataset som återspeglar processmätningarna under normala operationer och attackscenarier. Totalt 23 angreppsscenarier modelleras och utförs i den digitala tvillingen och dessa scenarier tillhör fyra olika angreppstyper, namnskommandoinjektion, nätverks -DoS, beräknad mätinjektion och naiv mätinjektion. Dessutom innehåller det föreslagna ramverket också ett maskininlärningsbaserat system för intrångsdetektering. Detta intrångsdetekteringssystem är utformat i två steg. Det första steget innebär en offline -utvärdering av prestanda för åtta olika algoritmer för maskininlärning övervakad på den märkta datauppsättningen. I det andra steget modelleras en staplad ensemble -klassificerarmodell som kombinerar de bäst presterande övervakade algoritmerna på olika etiketter för utbildningsdataset som den slutliga modellen för maskininlärning. Denna staplade ensemblemodell tränas offline med hjälp av den märkta datauppsättningen och används sedan för att klassificera inkommande dataprover från den digitala tvillingen under systemets levande drift. Resultaten visar att det konstruerade intrångsdetekteringssystemet kan upptäcka och klassificera intrång i nära realtid (0,1 sekunder). Det praktiska och fördelarna med den föreslagna digitala tvillingbaserade säkerhetsramen diskuteras också i detta arbete.
145

On the use of singular perturbation based model hierarchies of an electrohydraulic drive for virtualization purposes

Zagar, Philipp, Scheidl, Rudolf 25 June 2020 (has links)
Virtualization of products means the representation of some of their properties by models. In a stronger digitalized world, these models will gain a much broader use than models had in engineering so far. Even for one modelling aspect different models of the same product will be used, depending on the specific need of the model user. That need may change in the course of product life, between first product concepts till over the different phases of development, to product use, maintenance, or even recycling. Since a digitalized world use of these diverse models will not be limited to experts model consistency will play a much stronger role. Model hierarchies will play a stronger role and can serve also as means for teaching product users a deeper understanding of product properties. A consistent model hierarchy leading from a simple to a more advanced property representation can support this learning process. In this paper perturbation methods are analyzed as a means for setting up model hierarchies in a consistent manner. This is studied by models for the behavior of a electrohydraulic drive, which consists of a variable speed motor, a pump, a double stroke cylinder and a counterbalance valve. Model hierarchy is achieved by model reduction in the sense of perturbation theory. The use of these different models for different questions in a system design context and their interrelations are exemplified.
146

Development of Advanced Process Control for Controlling a Digital Twin as a Part of Virtual Commissioning

Uddin, Md Mehrab January 2021 (has links)
Over the last few decades, the complexity and variety of automation systems have increased dramatically. Commissioning has grown more and more critical for the entire industry. Conventional commissioning is time-consuming and expensive. It's always been a challenge in manufacturing to put new designs into production or implement new technologies, control codes, or tactics. In Virtual Commissioning (VC), control programs of the physical system's Digital Twin (DT) can be validated in Software-in-the-Loop (SIL) before the actual commissioning. The emergence of new VC tools and methods has become a tremendous advantage, bringing the values of shorter duration, flexibility, and lower risks to the commissioning process. In this thesis, advanced process control was developed using the software Matlab and Simulink in conjunction with the engineering tools S7-PLCSIM Advanced and STEP 7 TIA Portal to conduct VC. A VC approach with four key steps is taken to evaluate the possibility of validating advanced process control. The steps are modeling DT of a rolling mill, model-based control design, simulation model development in Simulink, communication between the simulation model and the PLC program using S-7 TIA Portal, and PLCSIM Advanced. Also, a simulated Human-Machine Interface was designed to operate and visualize the process. VC of the rolling mill process was verified and validated by Model-in-the-Loop (MIL) and SIL simulation. The simulation gives satisfactory results as both MIL and SIL show identical outputs of the process.
147

Benefits & Challenges of Process Plant Digital Twins in Process Industries : A Single Case Study Approach in the Mineral Processing Industry

Jensen, Tobias January 2022 (has links)
Background: The Digital Twin is an increasingly trending technology that utilizes many of the key technologies relevant to the digitalization of industries and Industry 4.0, such as AI, Big Data, and IoT, to bring a virtual asset and a physical asset together to perform analysis and execute real-time decision making backed up by data (Grieves & Vickers, 2017; Rasheed et al., 2020). Current research on the benefits and challenges of Digital Twins in process industries is sparse and under-developed, and the significance of Digital Twins in their operational lifecycle phase requires investigation (Perno et al., 2020; Schleich et al., 2019; Sjödin, 2013). Research Questions: RQ1: What are the benefits of industrial process plant Digital Twins for companies in process industries? RQ2: What are the challenges that companies will face with industrial process plant Digital Twins in process industries? Literature Review: A theoretical framework was developed based on the applications, challenges, and enablers researched in other industries which acted as a foundation for the data collection process. Research Method: The thesis follows a qualitative research approach. A single-case study was employed with a large equipment supplier in the mineral processing industry, where data was collected through 17 semi-structured interviews with people possessing in-depth knowledge about the needs of the mineral processing industry. Findings: Five main benefits of industrial process plant Digital Twins in process industries were identified, Process performance, Monitoring and control, Predictive maintenance and scheduling, Business opportunities, and Safety. Correspondingly, four main challenges were identified, Perception and presentation, Privacy and security, Data management and performance, and Mutual scope and focus. Conclusions: The thesis project's managerial and theoretical implications include providing equipment suppliers in process industries with what benefits there lie with industrial process plant Digital Twins and which challenges must be overcome. By providing these benefits and challenges to equipment suppliers, they can prioritize which of these are most important to consider in their situation. The thesis contributes to the research of Digital Twins and adds to the sparse existing knowledge of what the benefits and challenges are of industrial process plant Digital Twins in process industries. The main limitation is the absence of process plant companies during the data collection phase.
148

Utilization of a tailormade condition monitoring device for third party motors

Grahn, Pontus January 2018 (has links)
Our society moves towards digitalization and the industry is not an exception. Siemenshas developed a wireless condition monitoring device called Simotics Connect in order tohelp them to move forward in the world of digitalization. The Simotics Connect has threeinbuilt sensors. One for temperature, one for vibrations and one for magnetic flux density,a product that is new in the market. This master thesis has investigated its usability forthird party motors, which has not been done.Four areas were investigated, the status in the current market, creating a motorgeometry estimation based on nameplate data, presenting a temperature model to calculatea motor’s cross section temperature and, finally, proposed a stator current model using themagnetic field measurement.Market research has shown that a space for the Simotics Connect to thrive in mostdefinitely exists.The motor geometry estimation, that is based on preliminary electromagnetic sizing,creates a digital twin for the motor that has sufficient accuracy as a tool when calculatinge.g. temperature calculations but lacks accuracy for more advanced and sensitivecalculations e.g for magnetic flux density measurement usability.The temperature model that is presented shows great accuracy when calculating thecross section temperature in the stator but the accuracy decreases for the cross sectiontemperature in the rotor.A stator current model is proposed using a proportional relationship between themagnetic flux density and stator current. The results indicates a linear relationship, thoughusing the digital twin to calculate the proportional constant were concluded to not beaccurate enough. / Sammhället rör sig idag mot digitalisering och industrin är ej ett undantag. Siemens harutvecklat en trådlös underhållsmätare kallad Simotics Connect för att hjälpa dem strävamot en värld inom digitalisering. Simotics Connect hat tre inbyggda sensorer. En för temperatur,en för vibrationer och en för magnetisk flödestäthet, vilket är nytt på marknaden.Detta masterprojekt har undersökt användningen av Simotics Connect för tredjepartsmotorer,vilket ej har gjorts tidigare.Fyra områden undersöktes, statusen på den nuvarande marknaden, en motorgeometriuppskattningmodellbaserad på namnskylsdata, en temperaturmodell för att beräknamotorns tvärsnittstemperatur och, slutligen, en statorströmmodell som använder sig avmagnetiska flödestäthetsmätningen.Marknadsundersökningen har visat att det finns ett utrymme för Simotics Connectatt blomstra inom på den nuvarande marknaden.Motorns geometriska uppskattning, som är baserad i preliminär elektromagnetiskgeometribestämning, skapar en digital tvilling av motorn som är tillräckligt noggrann föratt aggera som ett verktyg vid t.ex. temperatursberäkningar men saknar noggrannhet förmer avancerade och känsliga beräkningar, t ex för användbarhet inom magnetisk flödestäthetsberäkningar.Temperaturmodellen som presenteras visar stor noggrannhet vid beräkning av statornstvärsnittstemperatur, men noggrannheten minskar för rotorns tvärsnittstemperatur.En statorströmmodell föreslås med ett proportionellt förhållande mellan magnetflödesdensitetenoch statorströmmen. Resultaten indikerar ett linjärt förhållande, men användandetav den digitala tvillingen för att beräkna proportionell konstant konstateras attinte vara tillräckligt noggrann metod.
149

CALIBRATION AND VALIDATION OF A HIGH FIDELITY DISCRETE ELEMENT METHOD (DEM) BASED SOIL MODEL USING PHYSICAL TERRAMECHANICAL EXPERIMENTS

Omkar Ravindra Ghike (13163217) 27 July 2022 (has links)
<p>A procedure for calibrating a discrete element (DE) computational soil model for various moisture contents using a conventional Asperity-Spring friction modeling technique is presented in this thesis. The procedure is based on the outcomes of two physical soil experiments:</p> <p>(1) Compression and (2) unconfined shear strength at various levels of normal stress and normal pre-stress. The Compression test is used to calibrate the DE soil plastic strain and elastic strain as a function of Compressive stress. To calibrate the DE inter-particle friction coefficient and adhesion stress as a function of soil plastic strain, the unconfined shear test is used. This thesis describes the experimental test devices and test procedures used to perform the physical terramechanical experiments. The calibration procedure for the DE soil model is demonstrated in this thesis using two types of soil: sand-silt (2NS Sand) and silt-clay(Fine Grain Soil) over 5 different moisture contents: 0%, 4%, 8%, 12%, and 16%. The DE based models response are then validated by comparing them to experimental pressure-sinkage results for circular disks and cones for those two types of soil over 5 different moisture contents. The Mean Absolute  Percentage Error (MAPE) during the compression calibration was 26.9% whereas during the unconfined shear calibration, the MAPE was calculated to be 11.38%. Hence, the overall MAPE was calculated to be 19.34% for the entire calibration phase.</p>
150

Buildings in the Digital Era : An Explorative Study of Digital Twins in the Built Environment

Kästel, Siw Kristine, Wallén, Joanna January 2024 (has links)
In recent years, digital twins (DT) have gained traction in enhancing operation and maintenance procedures across various industrial sectors, such as manufacturing, energy, and aerospace. Yet their utilization remains more limited in the built environment. The aim of this paper is to investigate the current conceptualizations of DTs within the context of the Swedish built environment, shedding light on the maturity of DTs for built assets and the key value drivers influencing their adoption. The study reveals that DTs for built assets are in early developmental stages, lacking the maturity required to encompass the full spectrum of attributes inherent in a conventional DT. Despite stakeholders labeling these initiatives as DTs, our findings indicate a closer alignment with the concept of BIM-based digital models. This observation resonates with existing literature, highlighting the absence of a universally accepted definition for DTs. Within the Operations and Maintenance (O&amp;M) phase, we have identified the following four primary value drivers shaping the adoption of BIM-based DTs: 1) commercial transparency and trusted transactions, 2) efficiency and cost reduction in routine operations, 3) operational continuity, and 4) added services. These findings contribute to the ongoing discourse surrounding the convergence of BIM and DTs, offering insights into the practical implications and value propositions that drive the integration of these technologies within the built environment. / Under de senaste åren har användningen av digitala tvillingar (DT:ar) blivit allt vanligare för drift- och underhållsförfaranden inom olika industrisektorer, såsom tillverkning, energi och flyg- och rymdindustrin. Användningen är dock fortfarande begränsad inom bygg- och fastighetsbranschen. Syftet med denna studie är att undersöka de nuvarande konceptualiseringarna av DT:ar inom ramen för den svenska fastighetsbranschen, belysa mognaden hos tekniken och undersöka de viktigaste värdedrivande faktorerna som påverkar utvecklingen och användningen i drift- och underhåll av fastigheter. Studien visar att användningen av DT:ar i fastighetsbranschen befinner sig i ett tidigt utvecklingsstadie och att begreppet inom industrin inte helt överensstämmer med visionen kring konceptet. Resultaten stämmer överens med befintlig litteratur, som belyser avsaknaden av en allmänt accepterad definition för DT:ar. I drift- och underhållsfasen har vi också identifierat följande fyra primära värdedrivande faktorer för användingen av BIM-baserade DT:ar: 1) kommersiell transparens och pålitliga transaktioner, 2) kostnadsbesparingar i rutinmässigt drift- och underhållsarbete, 3) kontinuerligt driftsarbete, samt 4) tilläggstjänster. Resultaten från denna studie bidrar till den pågående diskussionen om koncepten BIM och DT, och ger ytterligare insikt i de praktiska värdeskapande processerna och belyser användningsområden av DT:ar i fastighetsbranschen.

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