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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.
41

Digital twin of a safe system

Edenhamn, Johan January 2022 (has links)
At Epiroc’s drill rigs a safe system is installed to make sure the vehicle is driven in a safe manner. In the development both machine tests and hardware-in-the-loop (HIL) tests have been performed but when changes are made the firmware in the safe modules has to be updated. To speed up the process a digital twin would be beneficial. This enables testing of parameters and formulation of criteria detecting faults. The purpose of the work is to develop a digital twin for steering and braking safe functions and evaluate the performance using data from machines as well as data from a HIL-rig. Also, the impact of the hydraulic model used in the HIL-rig is investigated. When the model is built two test cases are used to investigate how well the model replicates the behaviour of the real system and how sensitive it is to what input data is used. The biggest difference in the data is the sampling time, machine logs have 80 ms interval while logs from the rig are logged every 5 ms. It is discovered that some of the fault detection functions work very well no matter what data is used while others must have the better resolution to be trusted. The complexity of the hydraulic model used impacts the pressures but seem to have little effect on which fault codes are activated. With this the main purpose is partly achieved and further investigation is needed before the model can be used for all fault codes.
42

REAL TIME SIMULATION AND HARDWARE-IN-LOOP TESTING OF A HYBRID ELECTRIC VEHICLE CONTROL SYSTEM

Medisetti, Praveen 08 August 2007 (has links)
No description available.
43

Automation of the creation and execution of system level hardware-in-loop tests through model-based testing

Almasri, Ahmed, Aronsson Karlsson, Viktor January 2022 (has links)
The automatic creation of test cases has been a well-researched area in recent years. Indeed, the industry’s testing procedure still uses the traditional way of manual practices. However, investigations are continued to deliver new methods, but research results have not been fully adopted. In this paper, the investigated method applies the model-based testing (MBT) method to evaluate the ability to automate the creation of hardware-in-the-loop (HIL) test cases, where generated tests are created using MBT tools. The tools’ properties were compared to each other through a literature study, with the result of selecting tools to be used in a case study, and the tools selected were GraphWalker and MoMuT. The generated test cases perform similarly to their manual counterparts regarding how the test cases achieved full requirements coverage. When comparing the effort needed for applying the methods, a comparable effort is required for creating the first iteration, while with every subsequent update, MBT will require less effort compared to the manual process. Both methods achieve 100% requirements coverage, and since manual testing is created and executed by humans, some requirements are favoured over others due to company demands, while MBT tests will be generated randomly.In addition, a comparison between the used tools showcased the differences in the models’ design and their test case generation. The comparison showed that GraphWalker has a more straightforward design method and is better suited for smaller systems, while’s MoMuT can handle more complex systems but has a more involved design method.The results of the thesis showed that using MBT tools proved helpful as it covers the system requirements, can be executed in HIL and helps discover faults within the requirements and HIL system. These facts satisfy the companies’ demands. This thesis shows a promising improvement in automating the test process within the vehicular domain.
44

Engine Selection, Modeling, and Control Development for an Extended Range Electric Vehicle

Cooley, Robert Bradley 22 October 2010 (has links)
No description available.
45

Digital Twin Sterilizer

Jacobsson, Sebastian, Johnsson, Marcus January 2024 (has links)
An autoclave is an advanced machine that sterilizes objects using high-pressure and high heat, with water steam as the medium. Autoclaves are frequently found in hospitals and other places where sterility is required. This project aims to meet the company's need to create a digital twin (DT) of an autoclave. The purpose is to test the control unit that controls the physical autoclave by exposing the DT to the same program as a real autoclave. A DT is a virtual model of a physical system, and in this project, it represented the autoclave and its sensors. The model was programmed in a graphical programming language NI LabView, with the same input and output signals as a real autoclave. The model was based on data-driven logic rather than physical based logic. From a real autoclave run where signals were recorded every second, conclusions could be drawn about how much each unique analog signal changed in combination with other signals through interpolation. The interpolation of the analog signals was used to capture the characteristics of these signals.  For validation, the DT was loaded into a Hardware In the Loop (HIL) system that simulates the autoclave with the DT but retains the control unit from the autoclave, which is the unit the company wants to test. The developed DT was tested against three goals describing how closely the values should align over an accumulated time. The results were compared each second between the real run and the DT run. The data-driven DT model met one of the three goals set, however, the DT model's characteristics resembled those of the real run, making the model useful as the control system does not interrupt the simulation for disallowed or deviant values. / En autoklav är en avancerad maskin som rengör objekt till en steril nivå med ett högt tryck och hög temperatur, där vattenånga används som medium. Autoklaven har ett vanligt förekommande på sjukhus och andra platser där sterilitet är ett krav. Det här projektet går ut på att möta företagets behov av att skapa en digital tvilling (DT) av en autoklav. Syftet är att testa kontrollenheten som styr den fysiska autoklaven genom att en DT ska utsättas för samma programkörning som en verklig autoklav. En DT är en virtuell modell av ett fysiskt system och i detta projekt var autoklaven och sensorerna i maskinen en DT. Modellen programmerades i ett grafiskt programmeringsspråk, NI LabVIEW med samma in- och utsignaler som en verklig autoklav. Modellen utgår ifrån en datadriven metod och inte en fysikalisk formulerad logik. Datan samlades in från en körning av en verklig autoklav, där signalerna sparades varje sekund. Slutsatser för hur mycket varje unik analog signal förändrades i kombination med övriga signaler kunde dras med hjälp av interpolering. Interpoleringen av de analoga signalera kunde användas för att fånga deras karakteristik.  För validering integrerades DT i ett Hardware In the Loop (HIL) system som hjälper till att simulera autoklaven. HIL-systemet har kontrollenheten kvar från autoklaven som är den enhet företaget vill utföra tester på. Den framtagna DT testades mot tre mål som beskriver hur nära värdena skall ligga under en ackumulerad tid. Resultatet jämfördes för varje sekund mellan den verkliga och DT körningen. Den datadrivna DT modellen uppfyllde 1 av 3 mål som ställdes, men DT modellens karakteristik efterliknade den från verkliga körningen vilket gör modellen användbar då kontrollsystemet inte avbryter simuleringen för ej tillåtna eller avvikande värden.
46

GNSS-based Spacecraft Formation Flying Simulation and Ionospheric Remote Sensing Applications

Peng, Yuxiang 18 May 2017 (has links)
The Global Navigation Satellite System (GNSS) is significantly advantageous to absolute and relative navigation for spacecraft formation flying. Ionospheric remote sensing, such as Total Electron Content (TEC) measurements or ionospheric irregularity studies are important potential Low Earth Orbit (LEO) applications. A GNSS-based Hardware-in-the-loop (HIL) simulation testbed for LEO spacecraft formation flying has been developed and evaluated. The testbed infrastructure is composed of GNSS simulators, multi-constellation GNSS receiver(s), the Navigation & Control system and the Systems Tool Kit (STK) visualization system. A reference scenario of two LEO spacecraft is simulated with the initial in-track separation of 1000-m and targeted leader-follower configuration of 100-m along-track offset. Therefore, the feasibility and performance of the testbed have been demonstrated by benchmarking the simulation results with past work. For ionospheric remote sensing, multi-constellation multi-frequency GNSS receivers are used to develop the GNSS TEC measurement and model evaluation system. GPS, GLONASS, Galileo and Beidou constellations are considered in this work. Multi-constellation GNSS TEC measurements and the GNSS-based HIL simulation testbed were integrated and applied to design a LEO satellite formation flying mission for ionospheric remote sensing. A scenario of observing sporadic E is illustrated and adopted to demonstrate how to apply GNSS-based spacecraft formation flying to study the ionospheric irregularities using the HIL simulation testbed. The entire infrastructure of GNSS-based spacecraft formation flying simulation and ionospheric remote sensing developed at Virginia Tech is capable of supporting future ionospheric remote sensing mission design and validation. / Master of Science / Global Navigation Satellite Systems (GNSS), such as the Global Positioning System (GPS), are not only used to navigate vehicles such as automobiles and spacecraft, but they are also used as a tool to remotely study the Earth’s ionosphere. A GNSS-based hardware simulation testbed for a group of spacecraft flying in low altitude orbit with the capability to remotely sense the ionosphere has been developed and evaluated. The hardware testbed developed is composed of GNSS signal emulators, GNSS signal receiver(s), the spacecraft navigation & control system and a mission visualization system. A reference scenario of two spacecraft in low altitude orbit with an initial horizontal distance of 1000-m and a final separation of 100-m is successfully simulated. Therefore, the feasibility and performance of the hardware testbed have been demonstrated by comparing the simulation results with past work. To study the Earth’s ionosphere, advanced GNSS receivers along with newly developed software are used to measure the ionospheric electron concentration. This software can be integrated with the hardware testbed and utilized to design spacecraft missions to study the ionosphere from the space. A scenario for observing a unique ionospheric structure is implemented to demonstrate application of the hardware testbed to more general ionospheric studies. Combining the software for ionospheric measurement and the hardware testbed for two spacecraft flying in formation can support future mission design and validation.
47

Design and control of a 6-phase Interleaved Boost Converter based on SiC semiconductors with EIS functionality for Fuel Cell Electric Vehicle / Etude et contrôle d’un hacheur élévateur à 6 phases entrelacées basé sur des composants SiC intégrant la fonctionnalité EIS pour véhicule électrique à pile à combustible

Wang, Hanqing 07 June 2019 (has links)
Cette thèse traite l’étude et le contrôle d’un hacheur élévateur à 6 phases entrelacées basé sur des semi-conducteurs en carbure de silicium (SiC) et des inductances couplées inverses pour véhicules électriques à pile à combustible (FCEV). . L'ondulation du courant dans la pile est combustible est considérablement réduite et la durée de vie de celle-ci peut être prolongée. Les semi-conducteurs en SiC, en raison de leurs faibles pertes, permettent de meilleures performances thermiques et une fréquence de commutation plus élevée. Les volumes des composants passifs (inductances et condensateurs) sont ainsi réduits. Grâce aux inductances à couplage inverse, les pertes du noyau magnétique et du bobinage sont réduites.La stratégie de contrôle par mode glissant est développée en raison de sa grande robustesse face aux variations de paramètres. La fonctionnalité de détection en ligne de spectroscopie d'impédance électrochimique (SIE) est intégrée avec succès à l’algorithme de contrôle par mode glissant.La validation HIL (Hardware In the Loop) en temps réel du convertisseur proposé est obtenue en implémentant la partie puissance dans le FPGA et la partie commande dans le microprocesseur du système de prototypage MicroLabBox de dSPACE. La comparaison entre la simulation hors ligne et la validation HIL a démontré le comportement dynamique du convertisseur proposé et validé la mise en œuvre du contrôle dans un contrôleur en temps réel avant de futurs tests sur un banc d'essai expérimental à échelle réduite. / The objective of this thesis work is devoted to the design and control of a DC/DC boost converter for Fuel Cell Electric Vehicle (FCEV) application. A 6-phase Interleaved Boost Converter (IBC) based on Silicon Carbide (SiC) semiconductors and inversed coupled inductors of cyclic cascade structure is proposed. The input current ripple is reduced significantly and the lifespan of Polymer Electrolyte Membrane Fuel Cell (PEMFC) can be extended. Low power losses, good thermal performance and high switching frequency have been gained by the selected SiC-based semiconductors. The volumes of passive components (inductors and capacitors) are reduced. Thanks to the inverse coupled inductors, the core losses and copper losses are decreased and the compact magnetic component is achieved.Sliding-Mode Control (SMC) strategy is developed due to its high robust to parameter variations. on-line Electrochemical Impedance Spectroscopy (EIS) detection functionality is successfully integrated with SMC. No additional equipment and sensor is required.The real-time Hardwar In the Loop (HIL) validation of the proposed converter is achieved by implement the power part into the FPGA and the control into the microprocessor in the MicroLabBox prototyping system from dSPACE. The comparison between off-line simulation and HIL validation demonstrated the dynamic behavior of the proposed converter and validated the implementation of the control into a real time controller before future tests on experimental test bench.
48

Modélisation et contrôle d’un robot spatial flexible pour la capture d’un débris en rotation / Modeling and Control of a Flexible Space Robot to Capture a Tumbling Debris

Dubanchet, Vincent 14 October 2016 (has links)
Les débris en orbite sont actuellement une source de préoccupation majeure pour les acteurs du spatial et pour le reste de la population, comme en témoignent les articles de presse et les œuvres cinématographiques sur le sujet. En effet, la présence de ces objets menace directement les astronautes en mission et les satellites en opération. Parmi les nombreuses options déjà envisagées pour les traiter, cette thèse se concentre sur l’approche robotique, en proposant des outils et des méthodes de modélisation et de contrôle pour un satellite chasseur équipé d’un bras manipulateur. Des modèles dynamiques et des schémas de simulation optimisés sont ainsi développés pour tout système multi-corps constitué d’une base mobile supportant un nombre quelconque d’appendices rigides ou flexibles. Par la suite, les trajectoires de capture sont générées en conservant la continuité en accélération avec le mouvement naturel du point cible, dans le but de saisir aussi délicatement que possible le débris en rotation. Le suivi de cette trajectoire par l’effecteur du robot chasseur est alors assuré par une loi de contrôle à deux niveaux, dont le réglage repose sur la synthèse H1 structurée. Une étude de robustesse est également mise en place pour assurer la stabilité et les performances du système en boucle fermée, malgré les changements de configuration du bras. Enfin, la validation des travaux de thèse est réalisée par voie numérique avec un simulateur haute-fidélité, et par voie pratique avec un banc d’essais robotique incluant des composants physiques en temps réel. / On-orbit debris are currently causing deep concern for space agencies, related companies, and also among the population. ¿is is evidenced by the numerous scientific articles and recent movies on the matter. Indeed, these objects pose a serious threat for the astronauts on mission and for operational satellites. Among the various technical concepts already designed to address these threats, this thesis focuses on space robotics. Tools and methods are thus introduced for the modeling and control of a chaser satellite equipped with a manipulator. Dynamic models and optimized simulation schemes are developed to handle any multi-body system made up of amoving base embedding various appendages, either rigid or flexible. ¿en, a trajectory planner is designed to ensure acceleration continuity with the natural motion of the debris in order to perform a soft capture. ¿is reference trajectory is tracked by the end-effector of the chaser using a two-level control law, which is tuned by the structured H1 synthesis. A robustness analysis is also presented to assess the stability and the performances of the closed-loop system with respect to the motion of the robotic arm. Finally, the outcome of the thesis is validated by a twofold approach: by numerical means with a highfidelity simulator, and by practical ones with a robotic test bench including physical components in real time.
49

Device-level real-time modeling and simulation of power electronics converters / Modélisation et simulation en temps réel au niveau composant des convertisseurs d’électronique de puissance

Bai, Hao 11 October 2019 (has links)
Pour le développement des convertisseurs d’électronique de puissance, la simulation en temps réel joue un rôle essentiel dans la validation des performances des convertisseurs et de leur contrôle avant leur réalisation. Cela permet de simuler et reproduire avec précision les formes d’ondes des courants et tensions des convertisseurs de puissance modélisés avec un pas de temps de simulation correspondant exactement au temps physique. Les circuits d’électronique de puissance sont caractérisés par le comportement non linéaire des interrupteurs. Par conséquent, les représentations des dispositifs de commutation sont cruciales dans la simulation en temps réel. Le modèle au niveau système est largement utilisé dans les simulateurs temps réel du commerce et les plates-formes expérimentales, qui modélisent les comportements des interrupteurspar deux états stationnaires distincts - passant et bloqué - et négligent tous les phénomènes transitoires. Ces dernières années, la simulation temps réel au niveau du composant est devenue populaire car elle permet de simuler les formes d'onde de commutation transitoires et de fournir des informations utiles concernant les contraintes sur les interrupteurs , les pertes, les effets parasites et les comportements électrothermiques. Néanmoins, la simulation temps réel au niveau du composant est contrainte par le pas de temps transitoire réalisable en raison des quantités de calcul accrues introduites par la non-linéarité du modèle de commutation.Afin d'intégrer le modèle au niveau du composant dans la simulation en temps réel, cette thèse porte sur l'exploration approfondie des techniques de modélisation et de simulation en temps réel au niveau composantdes convertisseurs d’électronique de puissance. Les techniques de simulation en temps réel les plus récentes sont d’abord examinées de manière exhaustive, tant au niveau du système que du composant. En outre, deux approches de modélisation au niveau du composant sont proposées, à savoir le modèle haute résolution quasi-transitoire (HRQT) et le modèle transitoire linéaire par morceaux (PLT). Dans le modèle HRQT, le modèle de réseau est implémenté par une simulation au niveau système tout en générant les formes d'onde de commutation transitoires avec une résolution de 5 ns, ce qui permet de simuler le convertisseur de puissance avec des transitoires rapides jusqu'à des dizaines de nanosecondes. Compte tenu des effets des transitoires sur l’ensemble du réseau, les modèles non linéaires des IGBT et diodes sont linéarisés par morceaux dans le modèle PLT. À l'aide de techniques efficaces de découplage de circuits, le modèle du convertisseur de puissance au niveau composant peut être simulé de manière stable avec un pas de temps de simulation global de 50 ns. Les deux modèles proposés sont testés et validés via différents cas sur une plate-forme temps réel de National Instruments basée sur un FPGA, comprenant un convertisseur boost boosté entrelacé (FIBC) pour le modèle HRQT, un convertisseur DC-DC-AC pour le modèle PLT et un convertisseur modulaire à plusieurs niveaux (MMC) pour les deux. Des résultats précis sont produits par rapport aux outils de simulation hors ligne. L'efficacité et les valeurs d'application sont également vérifiées par les résultats d’essais en temps réel. / In the development cycles of the power electronics converters, the real-time simulation plays an essential role in validating the converters’ and the controllers’ performances before their implementations on real systems. It can simulate and reproduce the current and voltage waveforms of the modeled power electronics converters accurately with a simulation time-step exactly corresponding to the physical time. The power electronics circuits are characterized by nonlinear switching behaviors. Therefore, the representations of switching devices are crucial in real-time simulation. The system-level model is widely used in both commercial real-time simulators and the experimentally built real-time platforms, which models the switching behaviors by two separate steady states – turn-on and turn-off, and neglects all the switching transients. In recent years, the device-level real-time simulation has become popular since it can simulate the transient switching waveforms and provide useful information with regard to the device stresses, the power losses, the parasitic effects, and electro-thermal behaviors. Nevertheless, the device-level real-time simulation is constrained by the achievable transient time-step due to the increased computational amounts introduced by the nonlinearity of the switch model.In order to integrate the device-level model in the real-time simulation, in this thesis, the device-level real-time modeling and simulation techniques of the power electronics converters are deeply explored. The state-of-art real-time simulation techniques are firstly reviewed comprehensively with regard to both system-level and device-level. Moreover, two device-level modeling approaches are proposed, including high- resolution quasi-transient model (HRQT) and the piecewise linear transient (PLT) model. In HRQT model, the network model can be implemented by system-level simulation while generating the transient switching waveforms with a 5 ns resolution, which is good at simulating the power converter with fast switching transients down to tens of nanoseconds. Considering the effects of the transient behaviors on the entire network, the PLT model is proposed by piecewise linearizing the nonlinear IGBT and diode equivalent models. With the help of effective circuit decoupling techniques, the device-level power converter model can be simulated stably with a 50 ns global simulation time-step. The proposed two models are tested and validated via different case studies on National Instruments (NI) FPGA-based real-time platform, including floating interleaved boost converter (FIBC) for HRQT model, DC-DC-AC converter for PLT model, and modular multi-level converter (MMC) for the both. Accurate results are produced compared to offline simulation tools. The effectiveness and the application values are further verified by the results of the real-time experiments.
50

Probing-based testing for SCADA systems : A novel method for hardware-in-the-loop integration testing of SCADA systems / Probbaserad testning av SCADAsystem : En ny metodik för integrationstestning av SCADAsystem på verklig hårdvara

Heddini, August January 2024 (has links)
Integration testing in software refers to a type of tests where system components are tested as a group for the purpose of verifying their interfaces. It is an important phase in system testing which aims at verifying the compliance of the system with specified functional requirements and the elimination of errors in the interaction of system components. Often integration testing is performed on complex systems with additional requirements for the testing approaches wherein the hardware limitations and time delays need to be taken into account. The testing of such systems is commonly performed through hardware-in-the-loop (HIL) tests. Despite the advances in both integration testing and HIL testing, combining the two for complex systems is still a challenging issue requiring a new set of potential solutions. In this thesis work we propose a new solution approach for HIL integration testing of Supervisory Control and Data Acquisition (SCADA) systems which does not require any simulation of the system under test. The solution presented in this thesis is based on the utilization of probes which are deployed to select component interfaces and through which real-time, inter-component communication can be observed without interference. The feasibility of the proposed approach is evaluated by applying it to a proof-of-concept test of the SCADA control system for a wave-energy converter in development by the thesis host company CorPower Ocean. In the results chapter we further discuss the architectural solution of the probing-based approach and provide further implementation details. Our conclusion is that the proposed approach corresponds to a promising, light-weight, and modular testing solution that can be used to perform live software integration tests of a fully connected system with little to no interference on its operation. / Inom mjukvarubranschen är integrationstester en typ av testning där grupper av systemkomponenter testas tillsammans för att säkerställa funktionaliteten av deras gränssnitt. Det är en viktig fas inom systemtestning som försäkrar att systemet som helhet uppfyller designkraven samt som minimerar felrisken i interaktioner mellan delkomponenter. Integrationstester utförs ofta på komplexa system där testningen i sig har ytterligare krav som inskränker metodvalet, till exempel då hänsyn behöver tas till hårdvarubegränsningar eller timing. Ofta genomförs testningen av sådana system med så kallade hardware-in-the-loop-tester (HIL). Trots modern utveckling inom både integrations- och HIL-testning är det fortfarande mycket utmanande att kombinera båda metoderna för komplexa system och nya lösningar behöver utvecklas och utvärderas. I denna avhandling föreslås en ny sådan lösning för HIL-testning av Supervisory Control and Data Acquisition (SCADA) -kontrollsystem som inte kräver att någon del av systemet simuleras under testernas utförande. Lösningen är baseras på användandet av mjukvarusonder som sätts in vid utvalda komponentgränssnitt och som i realtid kan observera interkomponentkommunikation utan störningspåverkan på komponenterna i sig. Den beskrivna lösningen utvärderades genom att utföra en praktisk konceptvalidering mot SCADAkontrollsystemet för avhandlingens värdbolag CorPower Oceans vågenergigenerator. I avhandlingen beskrivs även den arkitekturella lösning som krävdes för att genomföra sonderingsbaserad testning på ett reellt system samt implementationsdetaljer för konceptvalideringen. Slutsatsen är att den föreslagna lösningen beskriver en lovande och modulär testningsmetodik som kan användas för att genomföra mjukvaruintegrationstester av komplexa, sammankopplade system i realtid, utan simuleringar och utan betydande störningspåverkan på systemets operation

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