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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.
201

Proposta de uma metodologia para desenvolvimento de novo fornecedor de freios traseiros a tambor para veículos já em produção. / Proposal of a methodology for development of a new rear drum brakes supplier for vehicles already in production.

Maik Briscese Müller 24 August 2009 (has links)
O projeto de um sistema de freios a tambor é altamente especializado, por este motivo é um produto terceirizado ou black box, onde os fornecedores investem em pesquisas e detém patentes de sua construção e materiais. Porém, cabe a montadora definir os requisitos do produto, propor o plano de validação do projeto do freio à aplicação no veículo ao qual se destina e interpretar os resultados para aprovação. Parte da execução deste plano é delegada ao fornecedor (DFMEA, simulações numéricas, ensaios acelerados em bancada), enquanto as partes de certificação governamental, desempenho e durabilidade em veículo são de responsabilidade da montadora. A metodologia existente para desenvolvimento de freios a tambor destina-se ao desenvolvimento conjunto de um novo carro e um novo sistema de freio completo. Assim, além das incertezas sobre parâmetros do projeto de veículo que influem no projeto do freio, existe uma maior facilidade de se alterar os sistemas de interface do freio a tambor, uma vez que ainda não existem ferramentais produtivos. Este trabalho apresenta uma metodologia para o desenvolvimento de um novo fornecedor de freios traseiros a tambor para veículos já em produção, sob o ponto de vista da engenharia de produto. A metodologia proposta pretende atender as necessidades das montadoras de automóveis instaladas no Brasil, uma vez que estas necessitam buscar alternativas no fornecimento de sistemas automotivos de grande responsabilidade, com qualidade e custos globalmente competitivos. Esta metodologia é destinada à substituição do fornecedor (e portando no projeto) do freio a tambor, visando especialmente redução de custos, para veículos já em produção, procurando manter inalteradas as peças de interface, além de preservar ou, se possível, exceder os parâmetros de qualidade, durabilidade e desempenho do sistema ao qual virá a substituir. Para comprovar a metodologia apresentada, esta é aplicada a um caso real para um veículo de passeio pequeno, e então são apresentados os resultados parciais. / The project of a system of drum brakes is highly specialized, for this reason is a third part product, so-called black box product, where the suppliers invest in research and withhold patents of its construction and materials. However, the car OEMs define the requirements of the product, propose the validation plan for the brake project to the application in the vehicle it destines and evaluate the results for approval. Part of the execution of this plan is delegated to the supplier (DFMEA, numerical simulations, speed up bench tests), while steps of governmental certification, performance and durability in vehicle are of responsibility of the OEMs. The existing methodology for drum brake development destines to jointly development of a new car and a complete new brake system. Thereby, beyond uncertainties on parameters of the vehicle project that influence in the project of the brake, it is easier to modify the systems of interface with the drum brake, therefore productive tooling not yet exists. The dissertation purpose is to propose a methodology for development of new supplier of rear drum brakes for vehicles already in production, under the point of view of the product engineering. The methodology proposed intends to attend the needs of the car manufacturers installed in Brazil, once those are searching alternatives of suppliers of great responsibility automotive systems, with globally competitive costs and quality. The methodology proposed is destined to replace the supplier (and also the project) of the drum brake, aiming for cost reduction specially, for vehicles already in production, looking for keeping parts of interface unchanged and to maintain or, if possible, to exceed the parameters of quality, durability and performance of the system which it will come to substitute. To confirm the proposed methodology, this is applied to a real case for a small passenger vehicle and then the partial results are shown.
202

Veículos autônomos de transporte terrestre: proposta de arquitetura de tomada de decisão para navegação autônoma. / Autonomous ground transportation vehicles: proposal of making decision architecture for autonomous aavigation

Rodrigo de Sousa Pissardini 15 September 2014 (has links)
Veículos autônomos terrestres são um tipo de veículo motorizado guiado de forma autônoma por um sistema computacional, sem necessidade de intervenção humana. Esta pesquisa analisa a Tomada de Decisão autônoma necessária para este tipo de veículo, assim como os processos de navegação e as estruturas de dados que a suportam. Sobre esta análise propõe-se uma arquitetura de Tomada de Decisão para navegação autônoma baseada em dois ideias principais: a sistematização das fontes de dados com as quais o veículo deve interagir em sua navegação em uma hierarquia de prioridades de tratamento e o desenvolvimento de uma estrutura de dados chamada de Grade de Prioridades que permite definir para qual região do ambiente o veículo deve se locomover. Para suportar a arquitetura, formaliza-se um conjunto de processos recomendados de navegação robótica (percepção, posicionamento, planejamento e estratégia de movimento), organizados para suportar a integração com recursos de outras pesquisas do segmento da Robótica Móvel. Para validação da arquitetura, desenvolve-se um sistema de navegação robótica, integrada à uma plataforma robótica real, e realiza-se um conjunto de testes para simular o comportamento da arquitetura em situações de navegação específicas. / Autonomous ground vehicles are a type of motor vehicle autonomously guided by a computer system without human intervention. This research analyzes the autonomous decision making required for this type of vehicle as well as the processes of navigation and data structures that support it. On this analysis, is proposed an architecture of decision making for autonomous navigation based on two fundamental ideas: the systematization of data sources with which a vehicle must interact in their navigation in a hierarchy of priorities and the development of a special data structure called Grid Priorities that defines which region of the environment the vehicle must be moved. Supporting the architecture, a set of processes for robotic navigation (perception, positioning, planning and motion strategy) are proposed and organized to support integration with other research resources in the segment of Mobile Robotics. For validate the architecture, is developed a system of robotic navigation, integrated with a real robotic platform, and is performed a set of tests to simulate the behavior of the architecture in specific situations of navigation.
203

Estudo do sistema duto-trocador de calor compacto para veículos de competição. / Study of duct-compact heat exchanger system for race cars.

Eugênio José Borsatti 21 September 2010 (has links)
Esse estudo procura integrar as áreas de termodinâmica, transferência de calor e aerodinâmica no desenvolvimento de veículos de alto desempenho. É proposta uma ferramenta computacional que auxilie a análise de alternativas de trocadores de calor compactos, parte integrante do sistema de arrefecimento veicular. O aplicativo desenvolvido, denominado TROCALC, tem dois modos de uso: para colaborar no projeto de um trocador de calor ou para avaliar o desempenho de um trocador existente. Estruturado por um conjunto de equações e parâmetros com base na metodologia de Kays e London (1984), no primeiro modo esse aplicativo fornece alternativas de trocadores a partir dos dados de rejeição de calor por parte do motor e dos valores de vazão e temperatura dos fluidos envolvidos. Para o modo de avaliação de desempenho, além dos dados de entrada já mencionados, é necessário o detalhamento da geometria de superfície do trocador para calcular a quantidade de calor que o radiador é capaz de remover do sistema e comparar com o valor de fluxo de calor rejeitado pelo motor. É adotado um estudo de caso que considerou um veículo de competição da Fórmula SAE para investigar a eficácia do aplicativo TROCALC na análise de desempenho e na definição de novas alternativas para o trocador de calor dedicado àquele automóvel. Foram realizados ensaios em laboratório com a medição de valores para a rejeição de calor, vazão em massa de ar e perda de pressão no trocador existente. Os resultados validaram a ferramenta computacional e oferecem uma redução de 37% nas dimensões do trocador. Por fim é feita uma análise aerodinâmica para o conjunto duto-trocador de calor, que é uma solução típica utilizada em veículos de competição, integrando este conjunto à geometria da carenagem do veículo. Quatro alternativas, incluindo nova geometria para a carenagem do duto-trocador são investigadas do ponto de vista aerodinâmico com o auxílio de programa de dinâmica dos fluidos computacional (CFD). Nesta investigação, o objetivo é melhorar o comportamento de parâmetros relacionados ao escoamento de ar junto do sistema duto-trocador de calor, mantendo um bom comportamento para o arrasto total do veículo. / This study looks for the integration of thermodynamics, heat transfer and aerodynamics in the high-performance vehicles development. A computational tool that facilitates the compact heat exchanges analysis, part of the vehicle cooling system, is proposed. The application denominated TROCALC has two different modes of use: one for compact heat exchanger design and another one to evaluate existent heat exchangers performance. This program, which is structured by a set of equations and parameters based on the Kays and London (1984) methodology, provides heat exchangers alternatives through the input of the engine heat rejection, fluids temperature and mass flow (air and coolant). The tool is also capable of providing a performance analysis of an existent compact heat exchanger. In this case, besides of the inputs already mentioned, it is necessary to inform the surface geometry data of the actual heat exchanger to calculate the heat rejection capacity and compare to the established value of the engine. The case study of the Formula SAE is proposed in order to investigate the efficiency of TROCALC in performance analysis and definition of new alternatives for the Formula SAEs dedicated heat exchanger. Laboratory tests were performed in order to achieve experimentally the heat rejection, mass flow (air side) and pressure drop values in the current heat exchanger. The results validated the computational tool and offered a reduction of 37% in the heat exchangers dimensions. At last, aerodynamic analyses are performed for the duct-compact heat exchanger system, a typical solution adopted in race cars that is the integration of this set to the vehicles bodywork. Four alternatives are researched from the aerodynamic perspective with the computational fluid dynamics program support (CFD), including a new geometry for the duct. In this research, the aim is the improvement of parameters behavior related to the air flow around the duct-compact heat exchanger system, keeping a good behavior to the total drag of the vehicle.
204

Evolução de produtos automotivos = o caso do conjunto espelho retrovisor externo / Evolution of automotive products : case of exterior rearview mirror assy

Silva, Márcio de Puccio 18 August 2018 (has links)
Orientador: Geilson Loureiro / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T21:49:50Z (GMT). No. of bitstreams: 1 Silva_MarciodePuccio_M.pdf: 12210927 bytes, checksum: 8717d3c5839c70dc9b151a499ce64821 (MD5) Previous issue date: 2011 / Resumo: Esta dissertação versa sobre a engenharia de um produto objeto de evoluções sucessivas. O produto em questão é o conjunto de espelho retrovisor externo de um automóvel. O processo de engenharia evolui do projeto de engenharia de um conjunto de peças a serem montadas para um processo de engenharia de sistemas que leva em conta outros processos do ciclo de vida como o próprio processo de projeto e o processo de fabricação, ou seja, também uma abordagem de engenharia simultânea. Ao longo de sua evolução, os stakeholders, os requisitos, as funcionalidades e a arquitetura de um conjunto espelho retrovisor mudaram. Até 1980, o projeto era orientado para o atendimento à regulamentação do mercado onde o veículo era comercializado. A partir daí, requisitos visando uma maior satisfação dos clientes passaram a ser considerados. O desafio atual é produzir um conjunto espelho retrovisor que atenda todos os requisitos durante todo seu ciclo de vida, desde sua concepção no início do projeto para viabilizar uma idéia ou forma do design até o seu descarte, preocupando-se com a utilização de materiais que possam ser facilmente reciclados. Esta dissertação reporta passos necessários para reduzir o peso dos retrovisores externos dos veículos a partir da utilização de um material com menor peso específico. A mudança no material, no entanto, traz consequências no seu comportamento em relação a resistência à vibração e intemperismo. Por isso, mudanças no processo de projeto e fabricação são necessárias. A conclusão é que evoluções futuras de produtos como o espelho retrovisor precisarão considerar desde o início do seu processo de desenvolvimento engenharia de sistemas e engenharia simultânea para a sua realização / Abstract: This dissertation is about the engineering of a product subject to successive evolution. The product in this case is an exterior rearview mirror assembly for vehicle. The engineering process evolves from the engineering design of an assembly set to a systems engineering process that takes into consideration other life cycle processes. Examples of these other life cycle processes are engineering design, testing and manufacturing. In order to take into consideration these other life cycle processes, the engineering process follows a concurrent engineering approach. Along its evolution, stakeholders, requirements, functionalities and the architecture of the exterior rearview mirror assembly have changed. Up to 1980, the design was oriented to meet market regulations. From there onwards, customer satisfaction started to matter. Nowadays, the challenge is to develop the product, from the outset, taking into consideration all of its life cycle processes, up to disposal, taking into consideration the materials that can be easily recyclable. This dissertation reports the steps necessary to reduce the weight of the external mirrors by using materials with lower density. However, the change in the material, affects resistance to vibration and intemperism. Therefore changes in design and in the manufacturing process are required. In conclusion, future evolution of products such as the exterior mirror needs to consider from the outset of product development the use of systems engineering and concurrent engineering approaches / Mestrado / Projetos / Mestre em Engenharia Automobilistica
205

Automated Analysis of Automotive Read-out Data for Better Decision Making

Saleem, Muhammad January 2011 (has links)
The modern automobile is a complex electromechanical system controlled by control systems which consist of several interdependent electronic control units (ECUs). Analysis of the data generated by these modules is very important in order to observe the interesting patterns among data. At Volvo Cars Corporation today, diagnostic read-out data is retrieved from client machines installed at workshops in different countries around the world. The problem with this data is that it does not show a clear picture as what is causing what i.e. tracking the problem. Diagnostic engineers at Volvo Cars Corporation perform routine based statistical analysis of diagnostic read-out data manually, which is time consuming and tedious work. Moreover, this analysis is restricted to basic level mainly statistical analysis of diagnostic readout data. We present an approach based on statistical analysis and cluster analysis. Our approach focused on analysing the data from a pure statistical stand-point to isolate the problem in diagnostic read-out data, thereby helping to visualize and analyse the nature of the problem at hand. Different general statistical formulae were applied to get meaningful information from large amount of DRO data. Cluster analysis was carried out to get clusters consisting of similar trouble codes. Different methods and techniques were considered for the purpose of cluster analysis. Hierarchical and non-hierarchical clusters were extracted by applying appropriate algorithms. The results obtained from the thesis work show that the diagnostic read-out data consist of independent and interdependent fault codes. Groups were generated which consist of similar trouble codes. Furthermore, corresponding factors from freeze frame data which shows significant variation for these groups were also extracted. These faults, groups of faults and factors were later interpreted and validated by  diagnostic engineers.
206

Utformning av webbportal för tjänstlediga medarbetare vid Volvo Cars Engine och utexaminerade elever från Volvogymnasiet

Becirovic, Edina, Sabic, Samira January 2006 (has links)
This report describes the development of a web site for co-workers on leave of absence at Volvo Cars Engine AB and graduated students at Volvo Upper Secondary School in Skövde. The aim of the web site is to be a complement to existing communication channels in the promotion of the contact between the target group and the company. The work was divided into two parts; the first consisting of a preliminary study used to identify the information which the target group finds absent in their absence from their place of work/school, and the second part consisting of the development of a proposition of content layout and web site design. The finished proposition was presented along with a couple of alternatives for the technical implementation. The information department at Volvo Cars Engine AB in consultation with Volvo Cars IT will carry on the implementation, administration and further development of the proposed solutions. / Denna rapport beskriver utformningen av en webbportal för tjänstlediga medarbetare vid Volvo Cars Engine AB och utexaminerade elever vid Volvogymnasiet i Skövde. Syftet med portalen är att fungera som ett komplement till de befintliga kommunikationskanalerna i främjandet av kontakten mellan målgruppen och företaget. På sikt är målet att de tjänstlediga och utexaminerade eleverna ska välja att återkomma och satsa på olika karriärvägar inom Volvo. Arbetet bestod av två delar. I den första delen genomfördes en förstudie för att identifiera information som målgruppen tycker sig sakna vid deras frånvaro från arbetsplatsen/gymnasiet. Förstudien realiserades med intervjuer med ägarna och nyckelpersoner på företaget, samt med telefonintervjuer med ett slumpmässigt urval från målgruppen. Resultatet av förstudien användes i arbetets andra del som gick ut på att skapa ett förslag på innehållslayout och design av webbportalen. Den andra delen av arbetet delades in i fyra faser. Under de fyra faserna togs det fram ägar- och målgruppsanalys, innehålls- och kravspecifikation, sidstruktur och layout samt grafisk design för webbportalen, med tonvikt på användarvänlighet enligt rekommendationer från Jakob Nielsen. Utformningen av layouten och designen hade p.g.a. företagets policy utgångspunkt i företagskulturen vad gäller design och layout på de externa webblösningarna. Ett antal alternativ för den tekniska lösningen togs också fram. Dessa är open-source CMS på externt webbhotell, Volvo Cars portallösning på Volvo Cars webbserver, samt Fronter-portal på företaget DoubleClick AB´s server. Det färdiga förslaget presenterades tillsammans med ett antal alternativ för den tekniska lösningen. Implementationen, förvaltningen och vidareutvecklingen av de föreslagna lösningarna drivs vidare av informationsavdelningen på Volvo Cars Engine AB i samråd med Volvo Cars IT
207

TRANSCENDING SPEED, the Culture of Motorsport_a facility for the development and promotion of motorsport

Franco, Kyle Ryan 28 November 2005 (has links)
The facility for the development and promotion of motorsport in South Africa will aim to serve as a precedent for future race track development. It is an exploration into the culture of motor racing and how the culture of architecture is enhanced within this very realm. The aim of this discourse is to establish the criteria required for an improved experience trackside and create a relationship between motor racing and architecture that will exhibit the fundamental purpose of being at the track - the racing. / Dissertation (MArch(Prof))--University of Pretoria, 2007. / Architecture / unrestricted
208

Raman Signal Enhancement and CARS Microscopy

Naji, Majid January 2014 (has links)
Raman biosensors are appealing for many biomedical applications, due to their accuracy and speed. In addition, Raman microscopy is a non-labeled imaging technique that offers chemical contrast based on Raman vibrational frequencies. However, the weak Raman signal represents a significant obstacle to using Raman in biological applications. The objective of my PhD research, presented in this thesis, is to enhance the Raman signal, thereby enabling it to be used in a wide variety of biomedical applications. More specifically, the research focuses on two different Raman signal enhancement techniques. The first is to improve the Raman signal using hollow-core photonic crystal fibers; this enhanced the Raman signal of ethanol 40 times. The second approach is by generating a coherent anti-Stokes Raman scattering (CARS) signal. We demonstrated CARS microscopy of myelin (lipid-rich) structures using a single femtosecond Ti:sapphire laser, and a photonic crystal fiber (PCF) with two closely lying zero dispersion wavelengths (ZDWs). Generating low noise supercontinuum (Stokes beam) out of two closely lying ZDW PCFs, enabled us to perform fast data acquisition (84 μs per pixel) CARS imaging using a homebuilt microscope. However, the application of this fiber is often limited to CARS imaging of molecular species with vibrations at wavenumbers ≥ 2000 cm−1 Raman shift. In addition, as it is not a polarization maintaining fiber, it cannot be used for polarization CARS microscopy. A polarization-maintaining PCF with two far-lying zero dispersion wavelengths offers important advantages for polarization CARS microscopy, and for CARS imaging in the fingerprint region. This PCF, though commercially available, has had limited use for CARS microscopy in the C-H bond region. The main problem is that the supercontinuum from this fiber is typically noisier than that from a standard PCF with two closely-lying zero dispersion wavelengths. To overcome this, we determined the optimum operating conditions for generating a low-noise supercontinuum out of a PCF with two far-lying zero dispersion wavelengths, in terms of the input parameters of the excitation pulse. We measured the relative intensity noise (RIN) of the Stokes and the corresponding CARS signal, as a function of the input laser parameters in this fiber. We demonstrated that the results of CARS imaging using this alternate fiber are comparable to those achieved using the standard fiber for input laser pulse conditions of low average power, narrow pulse width with a slightly positive chirp, and polarization direction parallel to the slow axis of the selected fiber. Finally, we demonstrated a novel fiber-delivered, portable, multimodal CARS exoscope, for minimally invasive in-vivo imaging of tissues. The device was based on a micro-electromechanical system-scanning mirror and miniaturized optics, and light delivery by photonic crystal fibre. A single Ti:sapphire femtosecond laser approach is used to produce CARS and two photon excitation fluorescent and second harmonic generation images of different samples using the new setup. The high resolution and distortion-free images achieved with various samples, particularly in the reverse direction (epi), successfully demonstrate proof of concept, and paves the way to minimally or non-invasive in vivo imaging. Moreover, combining this novel endoscope with a portable femtosecond fiber laser will accelerate delivering multimodal nonlinear imaging endoscopy/microscopy to clinical bed-side applications.
209

Audit značky Mercedes-Benz v kategorii prémiových osobních vozidel / Brand audit of Mercedes-Benz in the category of premium passenger cars

Žídková, Jolana January 2013 (has links)
The thesis Brand audit of Mercedes-Benz in the category of premium passenger cars is concerned with the evaluation of the position of the brand Mercedes-Benz on the Czech market in comparison with its biggest competitors - BMW and Audi. This is also the main goal of the thesis. The first part of the thesis is focused on defining brand and terms that are connected with brand. Furthermore there is an explanation of brand management, more precisely positioning, marketing programs and secondary associations that are the basic tools of brand building and also introduction and explanation of brand audit. In the second part profiles of brands are assembled and brand audit of Mercedes-Benz based on results of qualitative and qualitative research is made. The conclusion consists of current brand positioning and brand management of Mercedes-Benz. This is also a secondary goal of the thesis.
210

Extraction of Material Parameters for Static and Dynamic Modeling of Carbon Black Filled Natural Rubbers

Sandell, Viktor January 2017 (has links)
Volvo Car Corporation (Volvo Cars) develops powertrain mounting systems that uses components made up largely of filled rubber materials. The development of such components is today relying on external suppliers to design components based on requirements set by Volvo. To reduce costs and lead-time in the development process the possibility of in-house design of such components at Volvo Cars is being investigated. For this to be possible, knowledge must be built concerning modelling the mechanical properties of rubber materials. As part of this a parameter extraction method for modelling of filled rubber materials intended for finite element use has been developed in this project. Both a simple static model fitting procedure and a more complex dynamic model fitting procedure are detailed. Mechanical testing of four filled natural rubber materials with varying hardnesswas carried out at the facilities of Volvo Cars and recommendations have been made regarding the limits of the equipment and the specific test body geometry used. It was found that the lower limit for dynamic testing in regards to displacement amplitude is 0.02 mm. The highest frequency recommended is dependent on the material hardness but a higher limit of 200 Hz is recommended for the softest material investigated. The upper limit was found to be necessary due to inertia effects in the material. The models used to describe the static behaviour were hyperelastic phenomenological models independent on the second invariant such as the Yeoh and the linear neo-Hookean models. The dynamic model used the overlay method to capture therate and amplitude dependent properties of filled rubber. A generalized viscoelastic-elastoplastic rheological model using Maxwell and friction elements in parallel with alinear elastic element was presented and used. These were limited to having maximumfive of each element and no attempts at minimizing this number was made in this work.The dynamic model was fitted to experimental data using a minimization procedure focusing on dynamic modulus and damping at a range of frequencies and strain amplitudes.The proposed fitting procedure is a three segment loop in which FE simulationsof the experimental data is used as both a correction and a validation tool.Model validation showed good correlation of the fitted model to measured databefore correction was attempted. The correction step did not improve the model qualityand the reason for this was identified as poor post-processing. The proposed method together with lessons learned during the course of the project will be of importance for the future in-house development of rubber components at Volvo Cars.

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