Toda variação dimensional de montagem está baseada no empilhamento entre geometrias por formas e furos/pinos de localização em dispositivos. A capacidade de se garantir a menor variação dimensional é proporcional ao número de empilhamentos e ao comportamento geométrico dos componentes para formar o conjunto. Quanto maior a dependência geométrica no empilhamento, maior a probabilidade de variação. Entenda-se por dependência geométrica as conseqüências dimensionais circunstanciadas pela geometria de contato entre componentes, que facilitarão ou não os processos produtivos. Por este conceito, as necessidades relativas ao controle produtivo baseiam-se na capacitação do processo à necessidade do produto e vice-versa (a um processo instalado, desenvolver o produto cuja fabricação seja capaz em garantir o seu desempenho). A capacitação do processo deve-se à garantia sobre controles de componentes e conjuntos, mediante a avaliação de correta aplicação de tolerâncias dimensionais e geométricas no projeto e na garantia do processo. O desempenho do produto está garantida pelos seis graus de liberdade traduzidos como referências de localização e montagem para a sua função. Aspectos relacionados à rigidez de estrutura são relevantes e poderão ser inseridos nos estudos para garantia de conceitos a serem avaliados. O diagrama operacional proposto tem como foco reunir atividades e padrões de desenvolvimento de produtos e capacitação do processo, gerenciados por ferramentas de desenvolvimento e qualidade e controle dos processos. O benefício principal do diagrama operacional está na identificação de correlação de atividades, padrões de variações e capacidades produtivas, por meio da criação de referências geométricas e dimensionais. Por meio deste diagrama operacional há o desenvolvimento associado à avaliação de validação de montagens de produtos. E ainda uma correlação conseqüente à otimização de processos e produtos. A base de dados para esse projeto está nos vários processos e conceitos de produtos empregados, na disponibilidade das referências bibliográficas sobre viii capacidades de sistemas de inspeção, introdução aos princípios de tolerância, intrínsecas ao desenvolvimento de produtos e processo, ao processo de validação de componentes, nas análises de tensões e deformações e pelo embasamento em tolerâncias dimensionais e geométricas pela ASME Y 14.5 M. Identifica-se ainda a padronização de aplicação de referenciais para inspeção e processos de união entre componentes, definidos por estratégias de localização. / All assembly dimensional and geometric variation are based on geometries stack ups by profiles, locating holes and pins on fixtures. There is a direct relation between the number of stack ups, the final variation and geometry of assembly components. The probability of variation is directly related to the geometry dependency, that are circumstances of dimensional consequences for product and process. Based on this concept, process control is related to the process capability and product performance, and vice-versa (based on a installed process, the product must be robust for that process). The process capability focus the components and assemblies assurance, based on the dimensional and geometric tolerance. Also the process assurances are about components and assemblies control, based on correct dimensional and geometric tolerance. The product performance is dimensionally assured by the six degrees of freedom translated as locating and assembly references for its function. Aspects related to the stiffness are relevant and the concepts will be presented. The proposed Operational Diagram is focused to meet activities and product pattern development with process capacity, managed by quality tools and process control methodology. The benefits of Operational Diagram are to identify and make the correlation among activities, capability and variation through dimensional and geometric references creation, with product and process continuous improvement. The data base for this proposal are in the multiples process and project applied, in the information, in the process validation based on statistical analysis, in the CAE tooling with basis on tolerance by ASME Y 14.5 M., that identify references application, referenced to the locating strategy.

O motor de combustão interna, embreagem, transmissão, diferencial, eixo Cardan, semi-eixos e rodas motrizes compõem o trem de potência de um veículo que, por diversas razões de refinamento e peso, oferecem baixa “resistência” aos ruídos decorrentes da irregularidade de rotação do motor. O presente trabalho reúne elementos para analisar os efeitos das flutuações de rotação (vibrações torcionais) presentes nos volantes de motores de quatro tempos, medidas em dinamômetro, no desenvolvimento de sistemas de embreagem. O uso de simulação matemática computacional permite amenizar ou eliminar os ruídos provenientes da transmissão no veículo protótipo, possibilitando assim ganhos significativos no tempo de desenvolvimento de discos de embreagem e/ou volantes de dupla massa. / The internal combustion engine, clutch, transmission, differential, propeller shaft, half shafts and driven wheels compose the powerline of a vehicle which, due to several reasons of refinement and weight, offer low noise "counter resistance" to engine irregularity. This report is a collection of elements to analyze the effects of the engine revolution irregularity (torsional vibration) present on flywheels of 4-stroke engines, as measured in dynamometer, in the development of clutch systems. The use of computer simulation allows to soften or to eliminate the noise deriving from the transmission of prototype vehicles with new powertrain combination (clutch discs and/or dual-mass-flywheels), bringing considerable development time gains.

O presente trabalho destina-se a resumir o processo de desenvolvimento de automóveis, mostrando os vários itens que influenciam na velocidade deste desenvolvimento, e propor uma base de raciocínio para se diminuir o tempo total para o projeto. / The present volume is destined to summarize the development process of automobiles, showing the many items responsible for speed up this development, and make a proposal for a thinking basis to shorten development time.

Os objetivos desta pesquisa foram levantar os benefícios auferidos pela aplicação de melhorias na ergonomia dos postos de trabalho e no abastecimento planejado de peças em uma linha de montagem automotiva, bem como identificar e verificar até que ponto pode-se gerar vantagens competitivas na redução do tempo de montagem do veículo, com a aplicação de investimentos tecnológicos em ergonomia na área de manufatura. A metodologia Methods Time Measurement (MTM), foi escolhida para mensurar as diferenças de tempos de processo, e para coleta e identificação de dados. Foram observadas duas linhas de montagem: a primeira denominada de inovadora, construída há três anos com investimentos em soluções ergonômicas, tanto no abastecimento quanto no processo, e outra, tradicional, construída há 20 anos, com poucos investimentos na área. De posse dos dados necessários dos sistemas estudados e com o uso da tecnologia MTM, a pesquisa avalia e propõe meios de mensurar os ganhos com a redução de atividades que não agregam valor ao produto, com o intuito de viabilizar investimentos em ergonomia em postos de trabalho padronizados, manipuladores, instalações mais modernas e até possuir um time de planejamento de processos de produção mais robusto. Neste trabalho, analisa-se também a influência da ergonomia no custo do produto final, qualidade, retrabalhos, afastamentos médicos e absenteísmo entre outros. / The objectives of this research were raise the benefits gained for the application of improvements in the ergonomics of the workstation in the planned supplying of parts in the automotive assembly line. As well as identifying and verifying until the point that can generate competitive advantages in the assembly time reduction of the vehicle, with the application of technological investments in ergonomics in the area of manufacture. The methodology Methods Time Measurement (MTM) was chosen to measure the differences of times of process, and for collection and identification of data. Two assembly lines were observed, the first called innovator, built three years ago with investments in ergonomic solutions, as much in the supplying as in the process, and another traditional one built 20 years ago, with few investments in the area. Using all necessary data of the studied systems and with the use of MTM technology, the research evaluates and recommends ways to measure the profits with the reduction of activities that not add value to the product. With the intention to make possible investments in ergonomics standardized workstation, manipulators, more modern installations and until have a planning process production team more robust. This work, also analyze the medical influence of the ergonomics in the cost of the final product, quality, rework, medical dismissal and absenteeism among others.

A crescente tendência de participação dos fornecedores no processo de desenvolvimento de produto da indústria automotiva, faz com que o estudo desta parceria se torne importante, tanto para as montadoras quanto para os fornecedores. O principal objetivo desta parceria é a utilização da capacidade de engenharia dos fornecedores (know-how), permitindo assim, a incorporação de novas tecnologias ao veículo e a redução dos custos de desenvolvimento das montadoras. Observa-se cada vez mais dentro da montadora, discussões sobre o co-desenvolvimento (co-design) nos projetos automotivos, níveis de integração com o fornecedor, fase do projeto adequada para o envolvimento dos fornecedores, o nível adequado de detalhamento das especificações técnicas utilizadas como referência inicial pelos fornecedores, a definição das responsabilidades de cada parceiro e o próprio processo para realização do desenvolvimento em parceria. O presente trabalho explora de que forma tais questões são atualmente abordadas na subsidiária brasileira de uma montadora, através do estudo de seus processos e ferramentas e da comparação com as informações disponíveis na bibliografia e estudadas no meio acadêmico. Com este trabalho, pretende-se fornecer informações que possam auxiliar montadoras e fornecedores na melhoria de seus processos internos de desenvolvimento de produto, principalmente nas questões relativas ao co-desenvolvimento (co-design). / The increasing trend of suppliers participation in the automotive industry product development process makes the study of this partnership important for automakers and suppliers. The main objective of this partnership is to take advantage of suppliers engineering capability (know-how) in order to bring new technologies to the vehicle and reduce automakers development costs. It is becoming more and more common inside automakers, discussions regarding co-design in automotive projects, supplier integration levels, suitable project phase to get suppliers involved, suitable level of details for automakers technical specifications used as initial reference by suppliers, the responsibilities definition of each partner and the process to perform development in a partnership relation. This work explores how these issues are currently addressed in a Brazilian automaker subsidiary, through the study of its processes and tools and the comparison with the information available in the bibliography and studied academically. Finally, this work intends to provide information that can assist automakers and suppliers to improve their internal product development processes, mainly regarding co-design.

Aluminium alloys have been seen a dramatic increase in transport manufacturing in past two decades. This is primarily driven by the achievement of effective weight-savings, increased vehicle fuel efficiency and reduced CO2 emissions in transport. One of the significant progresses in most recent years has been in the application of aluminium-intensive car body structure, in which the manufacturing of thin wall castings with improved ductility is one of the critical issues. High pressure die casting (HPDC) is a fast and economical near-net shape manufacturing method to produce thin wall components. Therefore the application of HPDC process to make thin wall structural components for aluminium-intensive car body structure is one of the most challenges in recent development. However, the currently available die cast aluminium alloys are unable to fulfil this requirement because of the insufficient ductility, which is essential for joining castings with sheets and extruded parts. This has become critical in further development and extensive acceptance in car manufacturing industry. Generally, the mechanical properties of die castings are determined by alloy composition, defect levels and microstructure in the castings. In the present study, the significant achievement is the development of Al-Mg-Si-Mn alloy for HPDC process to provide improved ductility in die castings in order to satisfy the requirement of mechanical properties, in particular ductility for the application in automotive body structure. Starting from the thermodynamic analysis and CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) modelling of Al-Mg-Si system for solidification and phase formation, the alloy composition was optimised using international standard tensile samples to review the effect of various alloying elements on the mechanical properties. Another achievement is the understanding of the solidification and microstructural evolution, the relationship between the microstructure and mechanical properties, and the strengthening mechanisms in the developed alloy. The solidification behaviour in the shot sleeve and in the die cavity was examined for the formation of the primary α-Al phase, eutectic Al-Mg2Si phases in the alloy. The morphology, size and size distribution of the primary α-Al phase were characterised under different solidification conditions. The growth morphology of the primary α-Al phase formed in the shot sleeve and in the die cavity was analysed using the Mullins-Sekerka instability theory and the growth rate of eutectic Al-Mg2Si phases during solidification was calculated using Jackson-Hunt theory. Still another achievement is the study of the effect of Mn and Fe on the morphology, size and distribution of various Fe-rich compounds in the Al-Mg-Si alloy produced by HPDC process. The assessment was associated with the mechanical properties of yield strength, ultimate tensile strength and elongation with different Fe and Mn contents. CALPHAD modelling of multi-component Al-Mg-Si-Mn-Fe and Al-Mg-Si-Fe systems was studied to find out the effect of Fe impurity in the Al-Mg-Si alloy. The precise accumulation of iron during HPDC using fully recycled materials was examined to predict the maximum cycles to produce castings with required mechanical properties. The strengthening mechanism and the relationship between the microstructure and mechanical properties are explored in the alloy made by secondary materials. Furthermore, the effect of nickel on the microstructure and mechanical properties of the die-cast Al-Mg-Si-Mn alloy was also studied in association with the formation of Ni-rich intermetallics during solidification in the die-cast Al-Mg-Si-Mn alloy containing different Ni contents. The final achievement is the understanding of the repeatability of die castings made by the new alloy with industrial scale components. The tensile properties of standard samples that were obtained directly from HPDC process and made by the machined die castings at different locations were further assessed for the reproducibility of casting components made by the Al-Mg-Si-Mn alloy. The distributions of yield strength, ultimate tensile strength and elongation of the tensile samples were analysed by the average values with standard deviations and by the Weibull statistical model with three parameters. The correlations between the mechanical properties and the microstructural features, porosity levels and fracture morphology were investigated for the different types of samples. It was found that three-parameter Weibull analysis was capable of analysing the reproducibility of die cast components and the scattering of tensile properties was mainly due to the presence of porosity and non-uniform microstructure in the die-castings.

Context. Variability management (VM) in automotive domain is a promising solution to reduction of complexity. Feature modeling, as starting point of VM, deals with analysis and representation of available features in terms of commonalities and variabilities. The work is done in the context of an automotive industry – Adam Opel AG. Objectives. This work studies the automotive specific problems with respect to feature modeling, investigates what decomposition and structuring approaches exist in literature, and which one of them satisfies the industrial requirements. The approach to feature modeling is synthesized, evaluated and documented. Methods. In this work a case study with survey and literature review is performed. Survey uses semi structured interview and workshops as data collection methods. Systematic review includes articles from Compendex, Inspec, IEEE Xplore, ACM Digital Library, Science Direct and Engineering Village. Approach selection is based on mapping requirements against discovered approaches and discussion with industry practitioner on the regular meetings. Evaluation is proposed according to Goal Question Metric paradigm. Results. The approach that can be followed in the case organization is described and evaluated. The reasoning behind feature modeling approach construction and selection can be generalized for other organizations as well. Conclusions. We conclude that there is no perfect approach that would solve all the problems connected to automotive software. However, structuring approaches can be complementary and while combining give a good results. Tool support that integrates into the whole development cycle is important, as the amount of information cannot be processed using simple feature modeling tools. There is a need for further investigation in both directions – tool support and structuring approaches. The tactics that are proposed here should be introduced in organizations and formally evaluated. / Tel. +4917661965859

In this thesis, a novel System-on-Package (SoP) antenna concept has been developed for 24 GHz automotive radar applications. High-performance applications such as automotive radars require miniaturization, excellent performance and a high level of integration. The multi-layer Low-temperature co-fired ceramic (LTCC) SOP approach is an effective solution to meet these stringent needs as it offers not only great capability of integrating embedded functions, but also the real estate efficiency and cost-savings. The antenna concept utilizes a mixed LTCC tape system and combines for the first time a fractal antenna array and an integrated grooved Fresnel lens. The overall gain of the system is 15 dB which includes a 6 dB gain enhancement due to the integration of the lens. The bandwidth is 1.8 GHz which is 7.5% of the center frequency. The three types of dielectric Fresnel lenses (grooved, multi-dielectric and perforated) have been investigated as gain enhancement and beam shaping components for high performance LTCC SoP applications. A high dielectric constant material has been utilized to realize the lenses in the LTCC medium. All three lenses perform well with significant gain enhancement (>6 dB) and beam shaping despite their compact sizes (2.4 cm x 2.4 cm). The excellent performance makes all three lenses highly suitable for high performance SoP applications with the grooved lens being most suitable due to the relative ease of fabrication.

Context. The share and importance of software within automotive vehicles is growing steadily. Most functionalities in modern vehicles, especially safety related functions like advanced emergency braking, are controlled by software. A complex and common phenomenon in today’s automotive vehicles is the distribution of such software functions across several Electronic Control Units (ECUs) and consequently across several ECU system software modules. As a result, integration testing of these distributed software functions has been found to be a challenge. The automotive industry neither has infinite resources, nor has the time to carry out exhaustive testing of these functions. On the other hand, the traditional approach of implementing an ad-hoc selection of test scenarios based on the tester’s experience, can lead to test gaps and test redundancies. Hence, there is a pressing need within the automotive industry for a feasible and effective verification strategy for testing distributed software functions. Objectives. Firstly, to identify the current approach used to test the distributed automotive embedded software functions in literature and in a case company. Secondly, propose and validate a feasible and effective verification strategy for testing the distributed software functions that would help improve test coverage while reducing test redundan- cies and test gaps. Methods. To accomplish the objectives, a case study was conducted at Scania CV AB, Södertälje, Sweden. One of the data collection methods was through conducting interviews of different employees involved in the software testing activities. Based on the research objectives, an interview questionnaire with open-ended and close-ended questions has been used. Apart from interviews, data from relevant ar- tifacts in databases and archived documents has been used to achieve data triangulation. Moreover, to further strengthen the validity of the results obtained, adequate literature support has been presented throughout. Towards the end, a verification strategy has been proposed and validated using existing historical data at Scania. Conclusions. The proposed verification strategy to test distributed automotive embedded software functions has given promising results by providing means to identify test gaps and test redundancies. It helps establish an effective and feasible approach to capture function test coverage information that helps enhance the effectiveness of integration testing of the distributed software functions.

Although the environmental imperative compels us to search for a low carbon system of mobility, contemporary society seemingly necessitates a low carbon automobility. The costs and impracticalities of low carbon vehicles are well documented, and although the cultural and semiotic nature of the car means that it has always been more than just a means of transport, less is known about how socio-cultural mores regarding the car might impact upon the transition to low carbon motoring. Because cars carry people, then they inevitably carry experiences and meanings too. However, a shift from conventional internal combustion-engined vehicles to more low carbon forms of propulsion, such as electric or hybrid vehicles, suggests that the nature – et ergo our experiences and perceptions – of the car will necessarily change. It is therefore desirable to investigate the contemporary ‘consumption’ of the car, not only as personal transport but also as status symbol, cultural artefact and experience, to assess how such a socio-cultural consumption might apply to low carbon vehicles and so ascertain the subsequent potential for a holistic low carbon automobility as part of a sustainable transport policy. A suite of methods was employed to investigate if or how contemporary automobilities can aspire to a low carbon automobility, or whether the everyday socio-cultural ‘consumption’ of the car might preclude a transition to low carbon vehicles. The notions of affect and/or non-representational theory were appropriated as a philosophical framework to look beyond a seemingly default postmodern ‘car-as-representation’ approach to the consumption of the car and so begin to explore a deeper, perhaps even subconscious, regard for the car. In addition, opinion was sought from stakeholders within the low carbon vehicle sector as to the technologies within, the prospects for, and the efficacy of, UK low carbon vehicle policy and its facilitation thereon, and also with a sample of EV drivers as to their experiences of electric cars. Responses to an initial online questionnaire appeared to deny any status or regard for the car beyond its utility. However, subsequent semi-structured interviews with motorists conducted (mostly) in their cars contradicted these findings, with a variety of expressed feelings – pride, empowerment, fortune – suggesting a deeper, subconscious regard for, reading of, and connection with, the car than is immediately apparent. Similarly, the utility of the electric car was transcended, this time by feelings of ‘greenness’ and ‘calm’ expressed by EV drivers. A stated amenability and aspiration by those interviewed for low carbon vehicles contrasted with an aspiration for sporty and prestige cars, suggesting an ingrained or innate idea as to what constitutes a truly desirable car. The more cultural facets of the car explored during focus group discussions established a connection between a car’s cultural representation and its meaning. Interviews with low carbon vehicle stakeholders suggest that while UK low carbon vehicle policy is broadly effective, is not as efficacious as it could be, in that itinerate market-led aspirations lack the fixity and certainty, in terms of both infrastructure and policy, that investors and consumers require, especially given a high entry price, the promise of lower running costs notwithstanding. In establishing where ‘here’ is regarding the consumption of the car and the implementation of a low carbon vehicle policy, this research provides a new perspective upon the appetite and potential for a transition to a future low carbon automobility, and shows the efficacy of appropriating the notions of affect and non-representational theory to a more holistic consumption of the car.