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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

A systems approach to the development and use of FMEA in complex automotive applications

Henshall, Edwin, Campean, Felician, Rutter, B. January 2014 (has links)
Yes / The effective deployment of FMEAs within complex automotive applications faces a number of challenges, including the complexity of the system being analysed, the need to develop a series of coherently linked FMEAs at different levels within the systems hierarchy and across intrinsically interlinked engineering disciplines, and the need for coherent linkage between critical design characteristics cascaded through the systems levels with their counterparts in manufacturing. The approach presented in this paper to address these challenges is based on a structured Failure Mode Avoidance (FMA) framework which promotes the development of FMEAs within an integrated Systems Engineering approach. The effectiveness of the framework is illustrated through a case study, centred on the development of a diesel exhaust aftertreatment system. This case study demonstrates that the structured FMA framework for function analysis supports an effective decomposition of complex interdisciplinary systems facilitating the DFMEA deployment through a series of containable, structured DFMEAs developed at successive system levels, with clear vertical integration of functional requirements and critical parameters cascade. The paper also discusses the way in which the approach supports deployment across engineering disciplines and domains, ensuring the integrity of information flow between the design and manufacturing activities.
2

Investigation of Transparent Photovoltaic Vehicle Integration

Zachary Craig Schreiber (11142147) 20 July 2021 (has links)
The pursuit to combat climate change continues, identifying new methods and technologies for sustainable energy management. Automakers continue developing battery electric vehicles while researchers identify new applications and materials for solar photovoltaics. The continued advancement of technology creates new holes within literature, requiring investigation to understand the unknown. Photovoltaic vehicle integration gained popularity during the 1970s but did not commercialize due to technology, economics, and other factors. By 2021 the idea resurfaced, showcasing commercial and concept vehicles utilizing photovoltaics. The emergence of new transparent photovoltaics presents additional options for vehicle integration but lacks literature analyzing the energy output and economics. The theoretical analysis investigated transparent photovoltaic replacing a vehicle’s windows. The investigation found that transparent photovoltaic vehicle integration generates energy and financial savings. However, due to high system costs and location, the system does not provide a financial payback period like other photovoltaic arrays. Improving cost, location, and other financial parameters create more favorable circumstances for the photovoltaic system. Furthermore, transparent photovoltaics provide energy saving benefits and some return on investment compared to regular glass windows.
3

Critérios na seleção de plásticos de engenharia para aplicações em veículos populares no Brasil. / Criteria on engineering plastics selection for low car\'s applications in Brazil.

Dorneles Filho, Augusto Marcelino Lopes 21 December 2006 (has links)
Este trabalho tem por objetivo propor alguns critérios básicos, para o desenvolvimento de plásticos de engenharia em aplicações, componentes e partes dos veículos chamados populares, particularmente no Brasil, em substituição a partes tradicionalmente usinadas, fundidas ou injetadas em ligas metálicas. A despeito da desconfiança que cerca alguns dos componentes em plásticos que se destinam às aplicações automotivas, (e uma das principais razões para isso, são as elevadas temperaturas presentes em algumas áreas do automóvel), as grandes indústrias do setor não deixam de conceber novos projetos em polímeros de alta performance, para aplicações tidas como críticas em termos de resistência geral. Os chamados plásticos de engenharia são preferivelmente escolhidos devido à sua fácil processabilidade, e sua flexibilidade em propiciar desenhos mais complexos, com boa estabilidade dimensional e uma excelente resistência à corrosão em ambientes de hostilidade química. No passado, as empresas claramente optavam pelos plásticos chamados de termofixos, que hoje estão quase esquecidos ou obsoletos (principalmente devido aos processamentos mais custosos e/ou mais lentos). Hoje são largamente substituídos pelos termoplásticos de engenharia. Atualmente, o consumo de plásticos em alguns carros brasileiros já alcança quase 130 kg de plásticos nos seus interiores e/ou exteriores (como o Ford KA, por exemplo), o que ajuda a reduzir o peso total do automóvel, aumentando a economia de combustível, reduzindo os custos de processos, aliada a uma excelente aparência superficial. Este trabalho versará sobre a possibilidade de se propor critérios mais objetivos na fase inicial de um processo de seleção de plásticos de engenharia (notadamente, poliamidas, acetais, poliésteres, e policarbonato), aumentando a eficácia da escolha e diminuindo custos (evitando erros e economizando tempo), como um guia prático de consulta para engenheiros e profissionais do setor automotivo brasileiro. / The main objective of this paper is to propose some basic economical and objective criteria for the engineering plastics development in applications, components and parts in the low-end cars segment (known in Brazil as popular cars), to replace traditional metallic machined, die-casted or injected parts. In spite of the lack of reliance in plastics components in automotive applications (one of them being the high temperature in the engine area), big industries in the sector always conceive new projects on high performance polymers for applications considered critical because of its general resistance. The named engineering plastics are preferably chosen due to its easy processing, complex design flexibility, with a good dimensional stability and an excellent resistance against corrosion in environments with chemical hostility. In the past, companies clearly selected the called thermo-stable plastics, almost forgotten or obsolete nowadays (mainly due to the high cost and/or slowness on processing). Today they are largely replaced by engineering thermoplastics. Nowadays, the consumption of plastics in Brazilian low-end cars already reached approximately 130 kg of plastics in their interior and/or exterior (like in Ford KA, for example), which helps to reduce total car weight, increasing the saving of fuel, mitigating process costs, besides to an excellent surface appearance. This paper will approach about the possibility of proposing more objective criteria in the initial phase of the engineering plastics selection (notably polyamides, acetals, polyesters, and polycarbonates), increasing the choice efficacy and diminishing costs (avoiding mistakes and saving time), as a practical consulting guide to engineers and professionals from the Brazilian automotive sector.
4

Estimation of Nonlinear Dynamic Systems : Theory and Applications

Schön, Thomas B. January 2006 (has links)
This thesis deals with estimation of states and parameters in nonlinear and non-Gaussian dynamic systems. Sequential Monte Carlo methods are mainly used to this end. These methods rely on models of the underlying system, motivating some developments of the model concept. One of the main reasons for the interest in nonlinear estimation is that problems of this kind arise naturally in many important applications. Several applications of nonlinear estimation are studied. The models most commonly used for estimation are based on stochastic difference equations, referred to as state-space models. This thesis is mainly concerned with models of this kind. However, there will be a brief digression from this, in the treatment of the mathematically more intricate differential-algebraic equations. Here, the purpose is to write these equations in a form suitable for statistical signal processing. The nonlinear state estimation problem is addressed using sequential Monte Carlo methods, commonly referred to as particle methods. When there is a linear sub-structure inherent in the underlying model, this can be exploited by the powerful combination of the particle filter and the Kalman filter, presented by the marginalized particle filter. This algorithm is also known as the Rao-Blackwellized particle filter and it is thoroughly derived and explained in conjunction with a rather general class of mixed linear/nonlinear state-space models. Models of this type are often used in studying positioning and target tracking applications. This is illustrated using several examples from the automotive and the aircraft industry. Furthermore, the computational complexity of the marginalized particle filter is analyzed. The parameter estimation problem is addressed for a relatively general class of mixed linear/nonlinear state-space models. The expectation maximization algorithm is used to calculate parameter estimates from batch data. In devising this algorithm, the need to solve a nonlinear smoothing problem arises, which is handled using a particle smoother. The use of the marginalized particle filter for recursive parameterestimation is also investigated. The applications considered are the camera positioning problem arising from augmented reality and sensor fusion problems originating from automotive active safety systems. The use of vision measurements in the estimation problem is central to both applications. In augmented reality, the estimates of the camera’s position and orientation are imperative in the process of overlaying computer generated objects onto the live video stream. The objective in the sensor fusion problems arising in automotive safety systems is to provide information about the host vehicle and its surroundings, such as the position of other vehicles and the road geometry. Information of this kind is crucial for many systems, such as adaptive cruise control, collision avoidance and lane guidance.
5

Critérios na seleção de plásticos de engenharia para aplicações em veículos populares no Brasil. / Criteria on engineering plastics selection for low car\'s applications in Brazil.

Augusto Marcelino Lopes Dorneles Filho 21 December 2006 (has links)
Este trabalho tem por objetivo propor alguns critérios básicos, para o desenvolvimento de plásticos de engenharia em aplicações, componentes e partes dos veículos chamados populares, particularmente no Brasil, em substituição a partes tradicionalmente usinadas, fundidas ou injetadas em ligas metálicas. A despeito da desconfiança que cerca alguns dos componentes em plásticos que se destinam às aplicações automotivas, (e uma das principais razões para isso, são as elevadas temperaturas presentes em algumas áreas do automóvel), as grandes indústrias do setor não deixam de conceber novos projetos em polímeros de alta performance, para aplicações tidas como críticas em termos de resistência geral. Os chamados plásticos de engenharia são preferivelmente escolhidos devido à sua fácil processabilidade, e sua flexibilidade em propiciar desenhos mais complexos, com boa estabilidade dimensional e uma excelente resistência à corrosão em ambientes de hostilidade química. No passado, as empresas claramente optavam pelos plásticos chamados de termofixos, que hoje estão quase esquecidos ou obsoletos (principalmente devido aos processamentos mais custosos e/ou mais lentos). Hoje são largamente substituídos pelos termoplásticos de engenharia. Atualmente, o consumo de plásticos em alguns carros brasileiros já alcança quase 130 kg de plásticos nos seus interiores e/ou exteriores (como o Ford KA, por exemplo), o que ajuda a reduzir o peso total do automóvel, aumentando a economia de combustível, reduzindo os custos de processos, aliada a uma excelente aparência superficial. Este trabalho versará sobre a possibilidade de se propor critérios mais objetivos na fase inicial de um processo de seleção de plásticos de engenharia (notadamente, poliamidas, acetais, poliésteres, e policarbonato), aumentando a eficácia da escolha e diminuindo custos (evitando erros e economizando tempo), como um guia prático de consulta para engenheiros e profissionais do setor automotivo brasileiro. / The main objective of this paper is to propose some basic economical and objective criteria for the engineering plastics development in applications, components and parts in the low-end cars segment (known in Brazil as popular cars), to replace traditional metallic machined, die-casted or injected parts. In spite of the lack of reliance in plastics components in automotive applications (one of them being the high temperature in the engine area), big industries in the sector always conceive new projects on high performance polymers for applications considered critical because of its general resistance. The named engineering plastics are preferably chosen due to its easy processing, complex design flexibility, with a good dimensional stability and an excellent resistance against corrosion in environments with chemical hostility. In the past, companies clearly selected the called thermo-stable plastics, almost forgotten or obsolete nowadays (mainly due to the high cost and/or slowness on processing). Today they are largely replaced by engineering thermoplastics. Nowadays, the consumption of plastics in Brazilian low-end cars already reached approximately 130 kg of plastics in their interior and/or exterior (like in Ford KA, for example), which helps to reduce total car weight, increasing the saving of fuel, mitigating process costs, besides to an excellent surface appearance. This paper will approach about the possibility of proposing more objective criteria in the initial phase of the engineering plastics selection (notably polyamides, acetals, polyesters, and polycarbonates), increasing the choice efficacy and diminishing costs (avoiding mistakes and saving time), as a practical consulting guide to engineers and professionals from the Brazilian automotive sector.
6

Multiband DRA for automotive applications with beam steering / Antenne multi-bandes à résonateur diélectrique et dépointage de faisceau pour applications automobiles

Chiu, Tzu-Ling 19 December 2017 (has links)
Les antennes à pointage électronique présentent des avantages significatifs dans les systèmes de communication sans fil. Malgré cela elles ne sont toujours pas implantées dans l'industrie automobile. En effet, l'espace limité et le toit en grande partie métallique freinent l’utilisation de ces aériens dans ce contexte contraint. De nombreux défis restent à relever pour concevoir un système efficace, peu encombrant, faible coût et permettant de rayonner sur 360°. L’objectif de cette thèse est donc la mise au point d’une antenne à balayage électronique pour application automobile fonctionnant dans la bande LTE. Un système de «type MIMO » est proposé. Une antenne à résonateur diélectrique efficace, multi-bandes et efficace est conçue selon une procédure de développement spécifique. Un déphaseur accordable est également mis au point et réalisé. Il utilise des commutateurs et un condensateur variable. Un déphasage de 360 degrés est obtenu, le dispositif est commandé électriquement. L’antenne et le déphaseur sont ensuite associés dans un système complet fonctionnant dans la bande LTE. Celui-ci utilise deux antennes identiques, une seule étant alimentée. Ce système complet est mesuré seul et sur le véhicule. Les résultats obtenus sont prometteurs et permettent d’envisager, moyennant quelques améliorations, une exploitation industrielle. Les études menées pour aboutir à ce dispositif sont détaillées dans le manuscrit. / Even though beam steering technology has significant advantages in wireless communication systems, it is still not implemented in the automotive industry. Indeed, the limited space and the large metal sheet on the rooftop are the challenges for such system. This thesis is focused on the design of the LTE beam steering antenna based on a MIMO system for an automotive environment. An appropriate multiband, efficient and compact Dielectric Resonator Antenna is conceived using a specific development procedure. Also, a tunable phase shifter is designed and realized with switches and a variable capacitor. It has 360 degrees phase shift and can be electrically controlled. The proposed DRA and phase shifter are integrated in a global antenna system for automotive application in the LTE band. We finally propose a MIMO system with an active beam steering radiation pattern. It is very compact and can be implemented on the vehicle rooftop. Using the proposed phase shifter, a beam steering antenna is obtained with a global coverage close to 360� for the antenna alone or on the vehicle. Measurements are made in the using context of the antenna. Finally, the developed system is, with some improvement, powerful for powerful enough for "commercial" automotive applications. The studies carried out to develop this antenna are detailed in this manuscript.
7

Electronic Application of Two Dimensional Materials

Suki N Zhang (10723164) 29 April 2021 (has links)
Recent advances in atomically thin two-dimensional materials have led to various promising technologies such as nanoelectronics, sensing, energy storage, and optoelectronics applications. Graphene with sp2-bonded carbon atoms densely packed in a honeycomb crystal lattice has attracted tremendous interest with excellent electrical, optical, mechanical, and chemical properties. In this work, graphene’s mechanical properties, chemical properties, and piezoelectric properties are explored as graphene is implemented in the automotive electrical distribution system. Graphene is useful in friction reduction, corrosion protection, and piezoelectric energy harvesting cell improvement. Besides graphene, transition metal dichalcogenides (TMDs), which are the metal atoms sandwiched between two chalcogen atoms, have also attracted much attention. Unlike graphene, many TMDs are semiconductors in nature and possess enormous potential to be used as a potential channel material in ultra-scaled field-effect transistors (FETs). In this work, chemical doping strategies are explored for the tunnel FETs applications using different metal phthalocyanines and polyethyleneimines as dopants. TMDs FETs can also be used as a selective NO<sub>2</sub> gas sensor with a polydimethylsiloxane filter and a highly sensitive photo-interfacial gated photodetector application.
8

Effect of Thermal and Chemical Treatment of Soy Flour on Soy-Polypropylene Composite Properties

Guettler, Barbara Elisabeth 06 November 2014 (has links)
Soy flour (SF), a by-product of the soybean oil extraction processing, was investigated for its application in soy-polypropylene composites for interior automotive applications. The emphasis of this work was the understanding of this new type of filler material and the contribution of its major constituents to its thermal stability and impact properties. For this reason, reference materials were selected to represent the protein (soy protein isolate (SPI)) and carbohydrate (soy hulls (SH)) constituents of the soy flour. Additional materials were also investigated: the residue obtained after the protein removal from the soy flour which was called insoluble soy (IS), and the remaining liquid solution after acid precipitation of the proteins, containing mostly sugars and minerals, which was called soluble sugar extract (SSE). Two treatments, potassium permanganate and autoclave, were analyzed for their potential to modify the properties of the soy composite materials. An acid treatment with sulfuric acid conducted on soy flour was also considered. The soy materials were studied by thermogravimetric analysis (TGA) under isothermal (in air) and dynamic (in nitrogen) conditions. SPI had the highest thermal stability and SSE the lowest thermal stability for the early stage of the heating process. Those two materials had the highest amount of residual mass at the end of the dynamic TGA in nitrogen. The two treatments showed minimal effect on the isothermal thermal stability of the soy materials at 200 ??C. A minor improvement was observed for the autoclave treated soy materials. Fourier transformed infrared (FTIR) spectroscopy indicated that the chemical surface composition differed according to type of the soy materials but no difference could be observed for the treatments within one type of soy material. Contact angle analysis and surface energy estimation indicated differences of the surface hydrophobicity of the soy materials according to type of material and treatment. The initial water contact angle ranged from 57 ?? for SF to 85 ?? for SH. The rate of water absorption increased dramatically after the autoclave treatment for IS and SPI. Both materials showed the highest increase in the polar surface energy fraction. In general, the major change of the surface energy was associated with change of the polar fraction. After KMnO4 treatment, the polar surface energy of SF, IS and SPI decreased while SH showed a slight increase after KMnO4 treatment. A relationship between protein content and polar surface energy was observed and seen to be more pronounced when high protein containing soy materials were treated with KMnO4 and autoclave. Based on the polar surface energy results, the most suitable soy materials for polypropylene compounding are SPI (KMnO4), SH, and IS (KMnO4) because their polar surface energy are the lowest which should make them more compatible with non-polar polymers such as polypropylene. The soy materials were compounded as 30 wt-% material loading with an injection moulding grade polypropylene blend for different combinations of soy material treatment and coupling agents. Notched Izod impact and flexural strength as well as flexural modulus estimates indicated that the mechanical properties of the autoclaved SF decreased when compared to untreated soy flour while the potassium permanganate treated SF improved in impact and flexural properties. Combinations of the two treatments and two selected (maleic anhydride grafted polypropylene) coupling agents showed improved impact and flexural properties for the autoclaved soy flour but decreased properties for the potassium permanganate treated soy flour. Scanning electron microscopy of the fractured section, obtained after impact testing of the composite material, revealed different crack propagation mechanisms for the treated SF. Autoclaved SF had a poor interface with large gaps between the material and the polypropylene matrix. After the addition of a maleic anhydride coupling agent to the autoclaved SF and polypropylene formulation, the SF was fully embedded in the polymer matrix. Potassium permanganate treated SF showed partial bonding between the material and the polymer matrix but some of the material showed poor bonding to the matrix. The acid treated SF showed cracks through the dispersed phase and completely broken components that did not bind to the polypropylene matrix. In conclusion, the two most promising soy materials in terms of impact and flexural properties improvement of soy polypropylene composites were potassium permanganate treated SF and the autoclaved SF combined with maleic anhydride coupling agent formulation.
9

Additive Manufacturing Applications for Suspension Systems : Part selection, concept development, and design

Waagaard, Morgan, Persson, Johan January 2020 (has links)
This project was conducted as a case study at Öhlins Racing AB, a manufacturer of suspension systems for automotive applications. Öhlins usually manufacture their components by traditional methods such as forging, casting, and machining. The project aimed to investigate how applicable Additive Manufacturing (AM) is to manufacture products for suspension systems to add value to suspension system components. For this, a proof of concept was designed and manufactured. The thesis was conducted at Öhlins in Upplands Väsby via the consultant firm Combitech.  A product catalog was searched, screened, and one part was selected. The selected part was used as a benchmark when a new part was designed for AM, using methods including Topology Optimization (TO) and Design for Additive Manufacturing (DfAM). Product requirements for the chosen part were to reduce weight, add functions, or add value in other ways.  Methods used throughout the project were based on traditional product development and DfAM, and consisted of three steps: Product Screening, Concept Development, and Part Design. The re-designed part is ready to be manufactured in titanium by L-PBF at Amexci in Karlskoga.  The thesis result shows that at least one of Öhlin's components in their product portfolio is suitable to be chosen, re-designed, and manufactured by AM. It is also shown that value can be added to the product by increased performance, in this case mainly by weight reduction. The finished product is a fork bottom, designed with hollow structures, and is ready to print by L-PBF in a titanium alloy.

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