Global ETD Search

1011	Evaluation of the Diagnostic Coverage for safety-relevant components in automated drive systems for mobile construction machinery Düsing, Christa, Inderelst, Martin 03 January 2024 (has links) The need for safety components in safety-related control systems arises in developing basic principles for preventing mechanical accidents and protecting safety for people and machines, especially in the development of automated drive systems for mobile construction machinery. An important parameter when using safety-relevant components respectively safety devices of automation technology-according to E DIN EN ISO 13849-1:2020-08 - in mobile machinery is the Diagnostic Coverage. The Diagnostic Coverage measures the effectiveness of the diagnosis as the ratio of the failure rate of noticed dangerous failures and failure rate of total dangerous failures. Because single- and dual-channel safety circuits from the Safety Related Parts of Control Systems (SRP/CS) might fail or get defective, a known level of Diagnostic Coverage helps to design such systems. As a supplementary method, the paper discusses the possibility of deriving a failure rate from empiric investigations via the context of fault classification known for electrical components from DIN EN 61508.-6:2011-02. Test procedures are not available in the development phase of new machines and new components in the field of mobile machines. Nevertheless, the Diagnostic Coverage is required for the calculation and design process. Similar to this test approach, the fault behaviour of technical products, defined in the FMEA (Failure Mode and Effects Analysis), can be applied to estimate the fault conditions in parallel to the design development as a first step. The target of estimating the diagnostic coverage already in the development phase of safety-relevant hydraulic components and systems can thus be achieved more effectively, and is illustrated in the article employing an example. The Diagnostic Coverage must be determined to classify the entire SRP/CS and each individual component according to ISO 13849 in category 2 and categories 3 & 4. In practice, this means that the calculation must be executed for the respective sensors, the controller and the actuator individually, and the entire functional channel as a whole in the single- or dual-channel safety circuit system. This enables an initial estimate and calculation of the Diagnostic Coverage according to ISO 13849 in the development phase without executing time-consuming prototype tests or test results from the field. This results in time savings and an increase in effectiveness of the internal work processes. Furthermore, the early avoidance of potential systematic risks of product and process failures, allows to reduce the costs of the development phase significantly. info:eu-repo/classification/ddc/629 ddc:629
1012	Design of a Switched Reluctance Motor for a Light Sport Aircraft Application Abdollahi, Mohammad Ehsan January 2022 (has links) With the rapid growth of air travel, concerns about the emissions of greenhouse gas emissions resulting from the air transportation sector are growing. Although the current battery technologies might not be adequate for all-electric regional aircraft, the energy density of the current battery technologies could be adequate to electrify light-sport aircraft used for training and recreation. Due to the nature of the propeller load and noise isolation of the cabin, switched reluctance motors can be an excellent candidate for the propulsion system of electrified light-sport aircraft. The proposed SRM is designed to replace a 70 kW permanent magnet synchronous motor used in the aerospace industry with similar volume constraints and operational requirements. In order to meet the high-power density requirements of this application, a design framework is proposed which includes several layers of the design process. The design objectifies are the average torque, torque ripple, and radial forces by integrating the control and geometry design into the proposed framework. A comprehensive design process is carried out with the proposed framework, and a detailed coil design process is performed. The rotor cut-outs are designed to reduce the weight of the motor. The thermal performance of the motor has been analyzed for the calculated motor losses and the cooling system constraints. / Thesis / Master of Applied Science (MASc) Direct drive motor Electric aircraft propulsion Finite element analysis Genetic algorithm Switched reluctance motor Light sport aircraft High power density motor design Green aviation Control integration High torque density Aerospace motor All electric aircraft Permanent magnet free electrical motor Switched reluctance machine
1013	Methodologies for FPGA Implementation of Finite Control Set Model Predictive Control for Electric Motor Drives Lao, Alex January 2019 (has links) Model predictive control is a popular research focus in electric motor control as it allows designers to specify optimization goals and exhibits fast transient response. Availability of faster and more affordable computers makes it possible to implement these algorithms in real-time. Real-time implementation is not without challenges however as these algorithms exhibit high computational complexity. Field-programmable gate arrays are a potential solution to the high computational requirements. However, they can be time-consuming to develop for. In this thesis, we present a methodology that reduces the size and development time of field-programmable gate array based fixed-point model predictive motor controllers using automated numerical analysis, optimization and code generation. The methods can be applied to other domains where model predictive control is used. Here, we demonstrate the benefits of our methodology by using it to build a motor controller at various sampling rates for an interior permanent magnet synchronous motor, tested in simulation at up to 125 kHz. Performance is then evaluated on a physical test bench with sampling rates up to 35 kHz, limited by the inverter. Our results show that the low latency achievable in our design allows for the exclusion of delay compensation common in other implementations and that automated reduction of numerical precision can allow the controller design to be compacted. / Thesis / Master of Applied Science (MASc) fpga field programmable gate array fcs finite control set hdl hardware description language rtl register transfer level numerical precision satisfiability modulo theories mpc model predictive control word length optimization electric drive electric motor permanent magnet synchronous motor interval arithmetic control system digital control inverter fixed point real time
1014	Minimization of Noise and Vibration Related to Driveline Imbalance using Robust Design Processes Al-Shubailat, Omar 17 August 2013 (has links) Variation in vehicle noise, vibration and harshness (NVH) response can be caused by variability in design (e.g. tolerance), material, manufacturing, or other sources of variation. Such variation in the vehicle response causes a higher percentage of produced vehicles to have higher levels (out of specifications) of NVH leading to higher number of warranty claims and loss of customer satisfaction, which are proven costly. Measures must be taken to ensure less warranty claims and higher levels of customer satisfactions. As a result, original equipment manufacturers (OEMs) have implemented design for variation in the design process to secure an acceptable (or within specification) response. The focus here will be on aspects of design variations that should be considered in the design process of drivelines. Variations due to imbalance in rotating components can be unavoidable or costly to control. Some of the major components in the vehicle that are known to have imbalance and traditionally cause NVH issues and concerns include the crankshaft, the drivetrain components (transmission, driveline, half shafts, etc.), and wheels. The purpose is to assess NVH as a result of driveline imbalance variations and develop a tool to help design a more robust system to such variations. program. Java quality engineering quality capability studies manufacturing processes manufacturing engineer design engineer sales profit customer concern warranty objectionable Eigen functions vectors Eigen Eigen values identity Euler differential equations differential transfer case shaft driveline static imbalance dynamic imbalance passenger customer driver inboard ear driver outboard ear steering wheel seat track variation Gamma distribution normal distribution standard deviation average variance mean phasor victor scalar linear system LTI linear time invariant transfer function output input microphone accelerometers tachometer channels order frequency frequency domain time domain convolution Transformation Fourier Transformer Fourier imaginary and real logarithmic decibel sensitivity curves run down run up two wheel drive Four Wheel Drive Nissan Truck OEM Original Equipment Manufacturers Data Acquisitions Channels Simulation Six Sigma variability Design Robust sensitivity Vibration Imbalance Noise Harshness NVH Driveline
1015	Towards sustainable urban transportation : Test, demonstration and development of fuel cell and hybrid-electric buses Folkesson, Anders January 2008 (has links) Several aspects make today’s transport system non-sustainable: • Production, transport and combustion of fossil fuels lead to global and local environmental problems. • Oil dependency in the transport sector may lead to economical and political instability. • Air pollution, noise, congestion and land-use may jeopardise public health and quality of life, especially in urban areas. In a sustainable urban transport system most trips are made with public transport because high convenience and comfort makes travelling with public transport attractive. In terms of emissions, including noise, the vehicles are environmentally sustainable, locally as well as globally. Vehicles are energy-efficient and the primary energy stems from renewable sources. Costs are reasonable for all involved, from passengers, bus operators and transport authorities to vehicle manufacturers. The system is thus commercially viable on its own merits. This thesis presents the results from three projects involving different concept buses, all with different powertrains. The first two projects included technical evaluations, including tests, of two different fuel cell buses. The third project focussed on development of a series hybrid-bus with internal combustion engine intended for production around 2010. The research on the fuel cell buses included evaluations of the energy efficiency improvement potential using energy mapping and vehicle simulations. Attitudes to hydrogen fuel cell buses among passengers, bus drivers and bus operators were investigated. Safety aspects of hydrogen as a vehicle fuel were analysed and the use of hydrogen compared to electrical energy storage were also investigated. One main conclusion is that a city bus should be considered as one energy system, because auxiliaries contribute largely to the energy use. Focussing only on the powertrain is not sufficient. The importance of mitigating losses far down an energy conversion chain is emphasised. The Scania hybrid fuel cell bus showed the long-term potential of fuel cells, advanced auxiliaries and hybrid-electric powertrains, but technologies applied in that bus are not yet viable in terms of cost or robustness over the service life of a bus. Results from the EU-project CUTE show that hydrogen fuelled fuel cell buses are viable for real-life operation. Successful operation and public acceptance show that focus on robustness and cost in vehicle design were key success factors, despite the resulting poor fuel economy. Hybrid-electric powertrains are feasible in stop-and-go city operation. Fuel consumption can be reduced, comfort improved, noise lowered and the main power source downsized and operated less dynamically. The potential for design improvements due to flexible component packaging is implemented in the Scania hybrid concept bus. This bus and the framework for its hybrid management system are discussed in this thesis. The development of buses for a more sustainable urban transport should be made in small steps to secure technical and economical realism, which both are needed to guarantee commercialisation and volume of production. This is needed for alternative products to have a significant influence. Hybrid buses with internal combustion engines running on renewable fuel is tomorrow’s technology, which paves the way for plug-in hybrid, battery electric and fuel cell hybrid vehicles the day after tomorrow. / QC 20100722 acceptance analysis auxiliary system bus Clean Urban Transport for Europe concept CUTE demonstration driver drive cycle duty cycle energy flow evaluation fuel cell heavy duty vehicle hybrid management hybrid vehicle hydrogen passenger PEM safety Sankey diagram series hybrid sustainable test urban transport vehicle simulation acceptans analys hjälpaggregat buss Clean Urban Transport for Europe koncept CUTE demonstration körcykel förare energiflöde utvärdering bränslecell tunga fordon hybridsystemkontroll hybridfordon vätgas passagerare PEM säkerhet Sankey-diagram seriehybrid uthållig hållbar test stadstransport fordonssimulering Vehicle engineering Farkostteknik Chemical engineering Kemiteknik
1016	Contribution to the Synchronous Reluctance Machine Performance Improvement by Design Optimization and Current Harmonics Injection / Contribution à l'amélioration des performances d'une machine synchrone à réluctance variable synchrone par optimisation de la conception et injection d'harmoniques de courant Yammine, Samer 06 November 2015 (has links) Cette thèse est consacré à l’évaluation et l’amélioration de la performance de la machine synchrone à réluctance variable pour des applications à vitesse variable en général et pour les applications automobiles en particulier. Les deux axes de développement sont la conception de la machine et l’injection des harmoniques de courants de phase. Le rotor est un élément important dans la conception de la machine, et un intérêt particulier est dédié à la conception et l’évaluation du rotor pour améliorer la performance de la machine. Une méthode analytique est proposée dans la thèse pour concevoir le rotor. Plusieurs éléments tels que les ponts qui maintiennent le rotor mécaniquement résistant, ainsi que le rapport d’isolation d’axe q (rapport air-acier) sont étudiés. Une étude de conception assistée par ordinateur basé sur un problème d’optimisation paramétrique est présentée aussi. Les trois familles des algorithmes d’optimisation sont évaluées pour la procédure d’optimisation: un algorithme à base de gradient (algorithme de Newton Quasi), un algorithme non-évolutionnaire sur la base de non-gradient (Nelder Mead Simplex) et un algorithme évolutif sur la base non-gradient (algorithme génétique). Les designs de machines basées sur la procédure analytique et la procédure d’optimisation sont testés sur un banc d’essai. Le deuxième axe d’études de la thèse est l’injection d’harmoniques dans les courants de phase de la machine à réluctance variable synchrone. L’interaction des harmoniques de courant avec les harmoniques spatiales des inductances est étudiée et formalisée pour une machine à m-phases. Ensuite, le concept d’injection d’harmoniques est évalué dans le cas particulier d’une machine à deux phases. Cette étude montre l’avantage de l’injection d’harmoniques dans la réduction de l’ondulation de couple de la machine. Un design d’une machine est ﬁnalement développé pour une application automobile sur la base de l’optimisation paramétrique du stator et du rotor. Cette conception est évaluée pour les spéciﬁcations imposées électromagnétiques par une application de traction à puissance moyenne / This thesis is dedicated to the evaluation and the improvement of the synchronous reluctance machine’s performance for variable speed drive applications in general and for automotive applications in particular. The two axes of development are machine design and phase current harmonics injection. The rotor is an important element in the machine design and particular emphasis is placed to the design and evaluation of the rotor for enhancing the machine performance. An analytical procedure is proposed for the rotor design. The rotor elements like the ribs and the bridges that maintain the rotor mechanically strong as well as the q-axis insulation ratio (air-to-steel ratio) are studied. A computer-aided design study based on a parametric optimization problem is presented as well. The main three families of the optimization algorithms are evaluated for the optimization procedure: a gradient-based algorithm (Quasi Newton Algorithm), a non-gradient based non-evolutionary algorithm (Nelder Mead Simplex) and a non-gradient based evolutionary algorithm (Genetic Algorithm). The machine designs based on the analytical procedure and the optimization procedure are both manufactured and tested on a bench. The second axis of study of the thesis is the injection of harmonics in the phase currents of the synchronous reluctance machine. The interaction of current harmonics with the spatial inductance harmonics is studied and formalized for an m-phase machine. Then, the harmonics injection concept is evaluated in the particular case of a 2-phase machine. This study shows the benefi t of harmonics injection in the reduction of the machine torque ripple. A synchronous reluctance machine design is fi nally developed for an automotive application based on parametric optimization of the stator and rotor. This design is evaluated for the electromagnetic specifi cations imposed by a mid-power electric vehicle traction application Couple Ondulations du couple Optimisation par conception Lignes de flux Harmoniques de courant Injection d’harmonique Machine à vitesse variable Zone de puissance constante Rapport de saillance Couple maximal par ampère Densité de puissance Densité de courant Synchronous Reluctance Machine (SynRM) Torque Torque Ripple Optimization Flux Lines Current Harmonics Harmonics Injection Variable Speed Drive (VSD) Field Weakening Speed Range Saliency Ratio Maximum Torque per Ampere (MTPA) Power Density Torque Density Insulation Ratio
1017	Contributions à la co-optimisation contrôle-dimensionnement sur cycle de vie sous contrainte réseau des houlogénérateurs directs / Contribution to the sizing-control co-optimization over life cycle under grid constraint for direct-drive wave energy converters Kovaltchouk, Thibaut 09 July 2015 (has links) Les Energies Marines Renouvelables (EMR) se développent aujourd’hui très vite tant au niveau de la recherche amont que de la R&D, et même des premiers démonstrateurs à la mer. Parmi ces EMR, l'énergie des vagues présente un potentiel particulièrement intéressant. Avec une ressource annuelle brute moyenne estimée à 40 kW/m au large de la côte atlantique, le littoral français est plutôt bien exposé. Mais l’exploitation à grande échelle de cette énergie renouvelable ne sera réalisable et pertinente qu'à condition d'une bonne intégration au réseau électrique (qualité) ainsi que d'une gestion et d'un dimensionnement optimisé au sens du coût sur cycle de vie. Une première solution de génération tout électrique pour un houlogénérateur a d’abord été évaluée dans le cadre de la thèse de Marie RUELLAN menée sur le site de Bretagne du laboratoire SATIE (ENS de Cachan). Ces travaux ont mis en évidence le potentiel de viabilité économique de cette chaîne de conversion et ont permis de poser la question du dimensionnement de l’ensemble convertisseur-machine et de soulever les problèmes associés à la qualité de l’énergie produite. Puis une seconde thèse a été menée par Judicaël AUBRY dans la même équipe de recherche. Elle a consisté, entre autres, en l’étude d’une première solution de traitement des fluctuations de la puissance basée sur un système de stockage par supercondensateurs. Une méthodologie de dimensionnement de l’ensemble convertisseur-machine et de gestion de l’énergie stockée fut également élaborée, mais en découplant le dimensionnement et la gestion de la production d’énergie et de ceux de son système de stockage. Le doctorant devra donc : 1. S’approprier les travaux antérieurs réalisés dans le domaine de la récupération de l’énergie des vagues ainsi que les modèles hydrodynamiques et mécaniques réalisés par notre partenaire : le LHEEA de l’Ecole Centrale de Nantes - 2. Résoudre le problème du couplage entre dimensionnement/gestion de la chaîne de conversion et dimensionnement/gestion du système de stockage. 3. Participer à la réalisation d’un banc test à échelle réduite de la chaine électrique et valider expérimentalement les modèles énergétiques du stockage et des convertisseurs statiques associés - 4. Proposer une méthodologie de dimensionnement de la chaine électrique intégrant le stockage et les lois de contrôle préalablement élaborées 5. Déterminer les gains en termes de capacités de stockage obtenus grâce à la mutualisation de la production (parc de machines) et évaluer l’intérêt d’un stockage centralisé - 6. Analyser l’impact sur le réseau d’une production houlogénérée selon divers scenarii, modèles et outils développés par tous les partenaires dans le cadre du projet QUALIPHE. L’exemple traité sera celui de l’Ile d’Yeu (en collaboration avec le SyDEV. / The work of this PhD thesis deals with the minimization of the per-kWh cost of direct-drive wave energy converter, crucial to the economic feasibility of this technology. Despite the simplicity of such a chain (that should provide a better reliability compared to indirect chain), the conversion principle uses an oscillating system (a heaving buoy for example) that induces significant power fluctuations on the production. Without precautions, such fluctuations can lead to: a low global efficiency, an accelerated aging of the fragile electrical components and a failure to respect power quality constraints. To solve these issues, we firstly study the optimization of the direct drive wave energy converter control in order to increase the global energy efficiency (from wave to grid), considering conversion losses and the limit s from the sizing of an electrical chain (maximum force and power). The results point out the effect of the prediction horizon or the mechanical energy into the objective function. Production profiles allow the study of the flicker constraint (due to grid voltage fluctuations) linked notably to the grid characteristics at the connection point. Other models have also been developed to quantify the aging of the most fragile and highly stressed components, namely the energy storage system used for power smoothing (with super capacitors or electrochemical batteries Li-ion) and power semiconductors.Finally, these aging models are used to optimize key design parameters using life-cycle analysis. Moreover, the sizing of the storage system is co-optimized with the smoothing management. Contrôle prédictif Dimensionnement sur cycle de vie Effets d'agrégation Entrainement direct Fiabilité Houlogénérateur direct Lissage de production Modèle de vieillissement Batteries Li-ion de puissance Supercondensateurs Principe du maximum de Pontryagin Semiconducteurs de puissance Stockage d'énergie Stratégie de contrôle optimisée Aggregation effect Aging model Power output smoothing Direct drive mechanism Direct wave energy converter Electrical chain optimization Energy storage Flicker Life cycle sizing Model predictive control Optimized rule-based control Pontryagin's maximum principle Power li-ion batteries Power semiconductor device Supercapacitors
1018	Užití programovatelných hradlových polí v systémech průmyslové automatizace / Field Programmable Gate Arrays Usage in Industrial Automation Systems Nouman, Ziad January 2016 (has links) Tato disertační práce se zabývá využitím programovatelných hradlových polí (FPGA) v diagnostice měničů, využívajících spínaných IGBT tranzistorů. Je zaměřena na budiče těchto výkonových tranzistorů a jejich struktury. Přechodné jevy veličin, jako jsou IG, VGE, VCE během procesu přepínání (zapnutí, vypnutí), mohou poukazovat na degradaci IGBT. Pro měření a monitorování těchto veličin byla navržena nová architektura budiče IGBT. Rychlé měření a monitorování během přepínacího děje vyžaduje vysokou vzorkovací frekvenci. Proto jsou navrhovány paralelní vysokorychlostní AD převodníky (> 50 MSPS). Práce je zaměřena převážně na návrh zařízení s FPGA včetně hardware a software. Byla navržena nová deska plošných spojů s FPGA, která plní požadované funkce, jako je řízení IGBT pomocí vícenásobných paralelních koncových stupňů, monitorování a diagnostiku, a propojení s řídicí jednotkou měniče.
1019	Modellierung, Simulation und Bewertung parallel-hybrider Antriebskonfigurationen für dieselhydraulische Triebwagen im Nah- und Regionalverkehr Kache, Martin 03 June 2014 (has links) Ausgangspunkt der Untersuchung ist die Frage, ob Hybridkonzepte auf hydrostatischer Grundlage eine realistische Alternative zu elektrohybriden Antriebskonfigurationen für Dieseltriebwagen sein können. Die Untersuchung dieser Fragestellung erfolgt mit Hilfe von Simulationsmodellen, die auf der 1-d-Simulationsumgebung Imagine.Lab AMESim beruhen. Zunächst wird die fahrdynamische und antriebstechnische Modellierung eines dieselhydraulischen Regionaltriebwagens unter Berücksichtigung einer energiesparenden Fahrweise dargestellt. Ausgehend von Massenbilanzen werden untereinander vergleichbare Hybridkonfigurationen auf hydrostatischer (Gasdruckspeicher), elektrostatischer (Doppelschichtkondensatoren) und elektrochemischer (Li-Ionen-Speicher) Basis entwickelt. Die Modellierung der hydraulischen und elektrischen Antriebsstränge wird eingehend diskutiert. Die abgeleiteten Hybridkonfigurationen werden anschließend bezüglich spezieller Fahrspiele und Betriebskonzepte detailliert untersucht, um auf dieser Grundlage günstige Parametrierungen der Systeme ableiten und die günstigste Betriebsstrategie identifizieren zu können. Anschließend wird eine umfangreiche Analyse des Verhaltens der verschiedenen Hybridkonfigurationen auf ausgewählten realen Nahverkehrsstrecken vorgenommen. Im Rahmen der durchgeführten Simulationen wird schließlich das Kraftstoffeinsparpotential in Abhängigkeit von Streckenprofil, Hybridkonfiguration und Zugart ermittelt und verglichen. info:eu-repo/classification/ddc/620 ddc:620
1020	Informing practice and sabotaging membership growth: an ideological rhetorical analysis of discursive materials from Kiwanis International Stokes, Tonja LaFaye 08 1900 (has links) Indiana University-Purdue University Indianapolis (IUPUI) / This study utilizes an ideological rhetorical analysis, applying Marxist and Feminist lenses, to artifacts from Kiwanis International, a prominent global service organization. These artifacts are: "The Permanent Objects of Kiwanis," guiding principles that were codified in 1924; "The Man Who Was God": a brief story about transforming from Kiwanis member to "Kiwanian," published in 1935 and 1985, respectively; and the 2012 "Join the Club" Membership Brochure. The rhetoric of discursive materials is one of the most salient representations of group ideology. In turn, ideology, particularly when it reflects and perpetuates social hegemony, has a normalizing effect on itself. Ideology shapes identity; identity shapes strategies to set process norms that create social cohesion. Norms of social cohesion become culture; culture reinforces ideology. When these components mirror social hegemony and replicate hegemonic power, they create institutions, like service organizations; these institutions then legitimate and normalize positions of social privilege. Ultimately, ideology and social hegemony reveal themselves through organizational and member practices and organizationally-produced discursive material. The purpose of this study is to analyze the historical, socio-political, and socio-cultural roots of Kiwanis International in order to draw logical conclusions about the organization's ideology for the purposes of understanding how that ideology contributes to, justifies, and perpetuates an unconscious, neo-colonial view of philanthropy. Kiwanis International, on an organizational (macro) level and at the club/member (micro) level, is structured around positions of racial, ethnic, socio-economic, linguistic, gender, and religious privilege, and so mimics the hegemonic power centers and dominant ideologies of society at large. In turn, the products and practices of the organization reflect these positions of privilege and inhibits the organization's ability to attract traditionally excluded, disenfranchised, or under-represented groups. Understanding that it is a contentious and futile to simply point where power relations exist and assert themselves, this study emphasizes where "othering" occurs in hopes of mitigating relations of domination and oppression between Kiwanis members and perspective members, and of moving forward the interests of those who have not traditionally been counted among Kiwanis' members but whose presence could save the organization. Rhetoric Rhetorical analysis Ideology Ideological analysis Marxism Feminism Marxist criticism Feminist criticism Reciprocity in community service Community service Membership organizations Voluntarism Neo-colonialism in voluntarism Imperialism in voluntarism Membership campaign Membership drive Kiwanis International Rotary International Lions Club Rhetoric Philosophy, Marxist Feminist theory Ideology Literature and society Social acceptance Social classes Social groups Social norms Social psychology Communication and culture Communism and culture Culture Social evolution Social conflict Marginality, Social Social isolation

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