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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.
1

SIMULINK Simulation of an Air-gapless Motor

Tang, Chuyue 08 October 2018 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / A SIMULINK simulation is presented for an air-gapless motor in this thesis. By considering magnetic saturation effect, four materials are compared and discussed in Chapter three.
2

The vulnerability of laser warning systems against guided weapons based on low power lasers

Al-Jaberi, Mubarak January 2006 (has links)
Laser assisted weapons, such as laser guided bombs, laser guided missiles and laser beam-riding missiles pose a significant threat to military assets in the modern battlefield. Laser beam-riding missiles are particularly hard to detect because they use low power lasers. Most laser warning systems produced so far can not detect laser beam-riding missiles because of their weak emissions which have signals less than 1% of laser range finder power . They are even harder to defeat because current counter-measures are not designed to work against this threat. The aim of this project is to examine the vulnerability of laser warning systems against guided weapons, to build an evaluation tool for laser warning sensors (LWS) and seekers, and try to find suitable counter-measures for laser beam-riding missiles that use low power lasers in their guidance systems. The project comes about because of the unexpected results obtained from extensive field trials carried out on various LWRs in the United Arab Emirates desert, where severe weather conditions may be experienced. The objective was to help find a solution for these systems to do their job in protecting the tanks and armoured vehicles crews from such a threat. In order to approach the subject, a computer model has been developed to enable the assessment of all phases of a laser warning receiver and missile seeker. MATLAB & SIMULINK software have been used to build the model. During this process experimentation and field trials have been carried out to verify the reliability of the model. This project will enable both the evaluation and design of any generic laser warning receiver or missile seeker and specific systems if various parameters are known. Moreover, this model will be used as a guide to the development of reliable countermeasures for laser beam-riding missiles.
3

The vulnerability of laser warning systems against guided weapons based on low power lasers

Al-Jaberi, Mubarak 28 April 2006 (has links)
Laser assisted weapons, such as laser guided bombs, laser guided missiles and laser beam-riding missiles pose a significant threat to military assets in the modern battlefield. Laser beam-riding missiles are particularly hard to detect because they use low power lasers. Most laser warning systems produced so far can not detect laser beam-riding missiles because of their weak emissions which have signals less than 1% of laser range finder power . They are even harder to defeat because current counter-measures are not designed to work against this threat. The aim of this project is to examine the vulnerability of laser warning systems against guided weapons, to build an evaluation tool for laser warning sensors (LWS) and seekers, and try to find suitable counter-measures for laser beam-riding missiles that use low power lasers in their guidance systems. The project comes about because of the unexpected results obtained from extensive field trials carried out on various LWRs in the United Arab Emirates desert, where severe weather conditions may be experienced. The objective was to help find a solution for these systems to do their job in protecting the tanks and armoured vehicles crews from such a threat. In order to approach the subject, a computer model has been developed to enable the assessment of all phases of a laser warning receiver and missile seeker. MATLAB & SIMULINK software have been used to build the model. During this process experimentation and field trials have been carried out to verify the reliability of the model. This project will enable both the evaluation and design of any generic laser warning receiver or missile seeker and specific systems if various parameters are known. Moreover, this model will be used as a guide to the development of reliable countermeasures for laser beam-riding missiles.
4

Διαδικασίες και αλγόριθμοι handover για συστήματα κινητής επικοινωνίας

Γιαννής, Στέλιος 27 March 2012 (has links)
Στην παρούσα εργασία παρουσιάζεται και αναλύεται διεξοδικά ο μηχανισμός μεταπομπής (handover) σε συστήματα κινητής επικοινωνίας. Οι μέθοδοι μεταπομπής βρίσκουν σημαντική εφαρμογή στα κυψελωτά συστήματα (cellular systems) και κατηγοριοποιούνται με βάση διάφορα χαρακτηριστικά τους, σε handovers σε σκληρά ή μαλακά, οριζόντια ή κάθετα, ελεγχόμενα από το Δίκτυο ή από την κινητή συσκευή, ή υποβοηθούμενα από την κινητή συσκευή. Σημαντικό ρόλο στις διαδικασίες handover παίζουν οι αλγόριθμοι απόφασης. Βασικές κατηγορίες αλγορίθμων απόφασης handover είναι αυτοί που στηρίζονται στη στάθμη της λαμβανόμενης ισχύος του σήματος, οι αλγόριθμοι που στηρίζονται σε fuzzy logic και οι αλγόριθμοι προτεραιότητας. Στην παρούσα εργασία προσομοιάζεται ένας αλγόριθμος προτεραιότητας γνωστός ως SJ-scheme με χρήση του λογισμικού Matlab και ειδικότερα των υποσυστημάτων του Simulink και Stateflow. Το προταθέν μοντέλο αποτελείται από έξι βασικά επιμέρους υποσυστήματα: το Υποσύστημα Εισόδου (Input Subsystem), το Υποσύστημα Καθορισμού της Χωρητικότητας των Καναλιών (Channels Size Subsystem), το Υποσύστημα Μνήμης (Memory Subsystem), το Υποσύστημα Ολοκλήρωσης Κλήσεων (Call Completion Subsystem), το Υποσύστημα των Αποτελεσμάτων (Scope Subsystem) και το Υποσύστημα Handover (Handover Subsystem) που αποτελεί την «καρδιά» του μοντέλου και περιλαμβάνει δύο βασικά blocks, ένα το οποίο υλοποιεί τη διαδικασία διαχείρισης νέων κλήσεων (New_calls_process) και ένα που υλοποιεί τη διαδικασία διαχείρισης των handovers (Handover_process). Πέραν της δημιουργίας μοντέλου προσομοίωσης, στην παρούσα εργασία παρουσιάζονται αναλυτικά και σχολιάζονται τα αποτελέσματα εκτέλεσης της προσομοίωσης και τα μετρούμενα μεγέθη. Μέσα από τις γραφικές αναπαραστάσεις που παράγονται και εξετάζονται, γίνεται αντιληπτός ο τρόπος λειτουργίας και οι ιδιαιτερότητες του προτεινόμενου μοντέλου. / In the current study the mechanism of switching between cells (handover) in mobile communication systems is presented and analyzed in detail. The handover methods are mainly applied in cellular systems and categorized according to various characteristics in hard or soft handovers, horizontal or vertical handovers, and handovers controlled by the network or the mobile device, or assisted by the mobile device. Handover decision algorithms play important role in the described processes. Main categories of handover decision algorithms are those based on the received signal strength, fuzzy logic and priority. In this study, a priority algorithm known as SJ-scheme is simulated, using Matlab software and, in particular subsystems Simulink and Stateflow. The proposed model consists of six major subsystems: Input Subsystem, Channels Size Subsystem, Memory Subsystem, Call Completion Subsystem, Scope Subsystem and Handover Subsystem which is the "heart" of the model and includes two main blocks, one that implements the new call management process and one that implements the procedure for managing handovers. Besides creating a simulation model, in this work results of running the simulation and measured data are presented and discussed. Matlab plots and graphical representations produced are examined to make clear the way that the proposed model works.
5

Dynamische Simulationskopplung von Simulink-Modellen durch einen Functional-Mock-up-Interface-Exportfilter

Lang, Jens, Rünger, Gudula, Stöcker, Paul January 2013 (has links)
Für den Austausch und zur Kopplung von Simulationsmodellen ist die Nutzung herstellerübergreifender Standards wie des Functional Mock-up-Interfaces (FMI) unerlässlich. In diesem Artikel wird eine Methode zum automatisierten Export von Simulationsmodellen aus Simulink in Module nach dem Standard FMI for Co-Simulation vorgestellt. Der automatisierte Export nutzt den Quelltextgenerator von Simulink und passt diesen über Templates für den Target Language Compiler so an, dass der erzeugte Quelltext das Functional Mock-up Interface implementiert. Der Artikel beschreibt die Methode zum Auslesen der Signaldefinitionen inkl. Bezeichner und Typen aus dem Simulink-Modell und die Methode zur Generierung des FMI-Quelltextes.
6

Development of an electric driveline model for multiscale road-cargo simulations / Utveckling av en elektrisk drivlinemodell för simuleringar av godstransporter på väg

Wu, Runzhe January 2022 (has links)
Currently, the road cargo system with low or zero CO2 emission is under rapid development. Heavy-duty trucks with electrified driveline systems will be the workhorse of future freight. But developing such a brand new and very complex system and adapting it to various application scenarios, such as long-haul freight, city distribution or construction loading, is still a big problem, because there is no previous experience to refer to. There is no standard development procedure or constraint framework for uncertainty either. Simulation on a massive scale with thousands of truck agents will be of great use for developing such a road-cargo system. System engineering will be the guiding methodology for this thesis project about developing a high-performance and multi-adaptive electrified driveline system. Referring to the classical V-shape development methodology, the complex concept will be divided into different levels of subsystems, from the large application scenarios to traffic simulation, driveline system simulation, electric motor and controller blocks development, and the system integration, performance verification and output of the results. The massive scale of traffic simulation will be implemented in AnyLogic, which does not contain any accurate agent model with vehicle dynamic motion during simulation. Thus, a precise vehicle agent model needs to be developed and embedded into AnyLogic’s simulation scenario, so as to make the simulation very close to reality, and to be able to evaluate vehicle concepts as well. The driveline system will be developed in Matlab/Simulink while the information communication between them will be realised in the form of computational calculation functions through the C language program. The development of the driveline model is also progressive. First, an equation-based full glider model was constructed. It simulates the scenario of a heavy-loaded truck driving on a steep slope (30% grade), decelerating from the initial 70 km/h to 0 km/h and then remaining stationary. The second model added the functionality of velocity input and output, enabling information exchange with AnyLogic. It will judge the real-time speed and the desired speed to decide whether to accelerate or decelerate and it uses the “Bang-Bang” control method of the electric motor. But this control mode results in a massive and frequent change in the electric motor output power, leading to extremely high energy consumption and in real life significantly shortened motor lifetime. So a powerful PI controller was introduced to the third Simulink model. The PI controller is embedded in the electric motor and it will replace the “Bang-Bang” control method. The “PID” control method provides a more stable power output so that the truck’s real-time speed can approach the target speed more smoothly. This control system can adapt to a variety of speed inputs and it can decide whether to output full power or partial power, depending on the speed difference. The third version of the Simulink model with PI controller has been verified as an acceptable model through various inputs of different speeds, and it will be converted into a C language program to be embedded in AnyLogic for massive traffic simulation. / Utveckling av godstrafiksystem på väg med låga eller noll CO2-utsläpp är under snabb utveckling. Tunga lastbilar med elektrifierade drivlinesystem kommer förmodligen att vara dominerande i framtiden för vägfrakt. Att utveckla ett helt nytt system med hög teknisk komplexitet och anpassning till olika tillämpningsscenarier, som fjärrtransport, distribution eller bygg och anläggning, är en stor utmaning på grund av kritiska begränsningar i exempelvis erfarenhet. Det finns heller ingen etablerad utvecklingsmetodik baserad på tidigare erfarenhet eller ramverk för att hantera osäkerheter. Simuleringar med tusentals lastbilsagenter kan vara till stor nytta och stöd för att utveckla lastbilssystem. Systemteknik kommer att vara den vägledande metodiken för detta examensarbete för att utveckla ett avancerat och multiadaptivt elektrifierat drivlinesystem. Med hjälp av den klassiska "V"-utvecklingsmetodiken kommer drivlinemodellen delas in i olika nivåer av delsystem utifrån de tidigare nämnda olika tillämpnings-scenarierna för trafiksimulering för att sedan utföra simulering av komplett drivlinesystem, utveckling av elmotor och reglersystem till systemintegration, prestandaverifiering och analys av resultat. Trafiksimulering är tänkt att implementeras i AnyLogic, som inte innehåller någon modell baserad på fordonsdynamik där drivlineegenskaper beaktas. Därför måste en specifk fordonsdynamikmodell utvecklas för fordonsagenten och bäddas in i AnyLogics simuleringsscenario för att göra simuleringen närmre verkligheten. Drivlinesystemet har utvecklats i Matlab/Simulink för att sedan realiseras i form av beräkningsfunktioner i C. Utvecklingen av drivlinemodellen görs iterativt. Först konstruerades en ekvationsbaserad full s.k. glidermodell. Den simulerar scenariot för en tung lastad lastbil som kör i en brant sluttning (30\% lutning), bromsar in från de ursprungliga 70 km/h till 0 km/h och förblir stillastående. I den andra modellen lades till gränssnitt för agentens begynnelsevärden och tillstånd vid tidsstegets slut, vilket möjliggjorde informationsutbyte med AnyLogic. Modellen analyserar realtidshastigheten och den önskade hastigheten för att sedan avgöra om agenten ska accelerera eller bromsa. Den använder "Bang-Bang"-reglermetoden för elmotorn. Men denna reglermetod resulterar i en frekvent och stor förändring av elmotorns uteffekt, vilket leder till hög energiförbrukning och i verkligheten avsevärt förkortad motorlivslängd. Därför introducerades en PI-regulator i den tredje Simulink-modellen. PI-regulatorn är inbäddad i elmotorn och ersätter "Bang-Bang"-reglermetoden. "PID"-regulatorn ger mer stabil effekt, så att lastbilens realtidshastighet mjukare kan närma sig målhastigheten. Detta reglersystem kan anpassas till en mängd olika begynnelsehastigheter och kan bestämma om full eller deleffekt ska matas ut beroende på skillnaden mellan realtidshastighet och målhastighet. Den tredje versionen av Simulink-modellen med PI-regulator har verifierats som en acceptabel modell genom olika begynnelsehastigheter och konverterats till ett C-program för att bäddas in i AnyLogic för trafiksimulering.
7

Development of Friction/Blended Braking Capability for an Electric Driveline Model for Multi-Scale Road-Cargo Simulations / Utveckling av friktion/blandad Bromsförmåga för en elektrisk Drivlinjemodell för Multi-Scale Road-Cargo Simuleringar

Wu, Fangge January 2023 (has links)
This thesis focuses on the critical development of friction and blended braking capabilities for an electric driveline model intended for multiscale road-cargo simulations. In the rapidly evolving landscape of transportation, electric driveline technology has emerged as a key player in achieving sustainability and efficiency goals. This study addresses the pivotal aspect of braking performance within this context, aiming to optimize energy utilization and enhance road safety. Using a systems engineering approach, MATLAB, and Simulink, the work in this thesis focused on the construction of a comprehensive model of a Volvo FH truck with friction/blended braking and an Anti-lock Braking System (ABS). The model underwent rigorous validation against the New European Driving Cycle (NEDC) and subsequent simulation under NEDC, US06, WLTC3 driving cycles. The primary objective was to assess the impact of activating or deactivating the blended control system on the State of Charge (SOC) and energy consumption. Through iterative refinement, the model's energy consumption per kilometer closely approximated actual FH truck test values. Activating the blended control system consistently led to reduced energy consumption across all driving cycles, underscoring its potential to enhance sustainable and safe transportation solutions. Importantly, the ABS system functioned effectively throughout the simulations, ensuring vehicle safety, while the model maintained a consistent output speed aligned with the input speed. This abstract summarizes the research's focus, methodology, and key findings, highlighting the successful development and validation of a Volvo FH truck model with friction/blended braking and ABS systems. The results underscore the blended control system's capacity to improve energy efficiency, contributing to the pursuit of sustainable and efficient transportation solutions in the evolving landscape of electric driveline technology. / Detta examensarbete fokuserar på utvecklingen av en elektrisk drivlinemodell som inkluderar mixning av konventionell friktionsbromssystem och den elektriska drivlinans moment under regenerering. Modellen är avsedd för multiskaliga väg-och godstransportsimuleringar. I den snabbt föränderliga transportsektorn är elektrisk drivlineteknologi en viktig del för att uppnå hållbarhets- och effektivitetsmål. Detta arbete behandlar den avgörande aspekten av bromsprestanda i detta sammanhang och har som mål att optimera energianvändningen och kontrollera vägsäkerheten. Genom att använda s.k. systems engineering-metodik, MATLAB och Simulink, utvecklades en dynamisk modell av en Volvo FH-lastbil med friktions-/mixad bromsning och system för låsningsfria bromsar (ABS). Modellen genomgick en rigorös validering mot New European Driving Cycle (NEDC) och efterföljande simuleringar enligt NEDC, US06 och WLTC3-körcykler. Det primära målet var att bedöma effekten av att aktivera eller inaktivera det mixade kontrollsystemet på laddningsnivå (SOC) och energiförbrukning. Genom iterativ förbättring approximerade modellen energiförbrukningen per kilometer nära de faktiska provvärdena för FH-lastbilar. Aktivering av det blandade kontrollsystemet ledde konsekvent till minskad energiförbrukning för alla körcykler och underströk dess potential att förbättra hållbara och säkra transportsystem. Det är viktigt att notera att ABS-systemet fungerade effektivt genom alla simuleringar och säkerställde fordonssäkerheten, samtidigt som modellen beräknade en hastighet i linje med körcykelns specificerade hastigheten. Denna sammanfattning sammanfattar forskningens fokus, metodik och huvudsakliga resultat och lyfter fram den framgångsrika utvecklingen och valideringen av en Volvo FH-lastbilsmodell med friktions-/mixad bromsning och ABS-system. Resultaten understryker det blandade kontrollsystemets förmåga att förbättra energieffektiviteten och bidra till strävan efter hållbara och effektiva transportsystem i den snabbt föränderliga världen av elektrisk drivlineteknologi.

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