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Behind the wheel : A closer look at influential relationships among internal factors driving a technological paradigm shiftHelleblad Nymo, Carl-Oscar January 2019 (has links)
Global sustainability awareness and governmental regulations are pushing the automotive industry into finding alternatives to carbon dioxide emitting products. Solutions utilizing electricity in the vehicle powertrain is overtaking market share from internal combustion engines (ICE). This tendency has spread into the heavy-duty truck segment which poses questions regarding the future of the ICE. An alternative, electric motors, powered with batteries, fuel cells of even ICE’s, is thought to become a core part of future mobility. To mitigate discontinuities during a shift from ICE to electric motors, a study of possible factors affecting such transition has been performed. The result indicates 14 main factors which are thought to have a definite role in a major technology paradigm shift. These factors are: Supplier relations, Material management, Material availability, Available space, Scalability, Product flexibility, Risk management, External resource utilization, Internal relations, Demand estimation, Management endorsement, Appropriate methodology, Employee engagement, and Competence renewal. A structure using ISM methodology is established highlighting the factors’ influencing relation to each other. Anchored in the theory regarding paradigmatic shifts within industry, a tendency of technological, managerial, and institutional influence on organizational change can be discerned where the institutional level poses as the fundamental dimension of derived quality. The factors are identified from a Scania specific case but are broad enough to apply to similar situations facing challenges of a technological paradigm shift.
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Enhanced Class 8 Truck Platooning via Simultaneous Shifting and Model Predictive ControlIfeoluwa Jimmy Ibitayo (6845570) 13 August 2019 (has links)
<div>Class 8 trucks on average drive the most miles and consume the most fuel of any major vehicle category annually. Indiana specifically is the fifth busiest state for commercial freight traffic and moves $750 billion dollars of freight annually, and this number is expected to grow by 60% by 2040. Reducing fuel consumption for class 8 trucks would have a significant benefit on business and the proportional decrease in CO<sub>2</sub> would be exceptionally beneficial for the environment.</div><div><br></div><div>Platooning is one of the most important strategies for increasing class 8 truck fuel savings. Platooning alone can help trucks save upwards of 7% platoon average fuel savings on flat ground. However, it can be difficult for a platooning controller to maintain a desired truck separation during uncoordinated shifting events. Using a high-fidelity simulation model, it is shown that simultaneous shifting–having the follow truck shift whenever the lead truck shifts (unless shifting would cause its engine to overspeed or underspeed)–decreases maximum truck separation by 24% on a moderately challenging grade route and 40% on a heavy grade route.</div><div><br></div><div>Model Predictive Control (MPC) of the follow truck is considered as a means to reduce the distance the follow truck falls behind during uncoordinated shifting events. The result in simulation is a reduction in maximum truck separation of 1% on a moderately challenging grade route and 19% on a heavy grade route. However, simultaneous shifting largely alleviates the need for MPC for the sake of tracking for the follow truck.</div><div><br></div><div>A different MPC formulation is considered to dynamically change the desired set point for truck separation for routes through a strategy called Route Optimized Gap Growth (ROGG). The result in simulation is 1% greater fuel savings on a moderately challenging grade route and 7% greater fuel savings on a route with heavy grade for the follow truck.</div>
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Adequação do design de interiores de cabines-leito de caminhões semipesados e pesados no Brasil às necessidades relacionadas ao uso como habitações temporárias / Suitability of the interior design of light-heavy-duty truck cabins in Brazil to the needs related to the use as temporary dwellingsMello, Ana Paula Scabello 03 August 2017 (has links)
A tese apresenta os aspectos relevantes que emergiram de pesquisa qualitativa e de abordagem fenomenológica e observacional a respeito da adequação do design de interiores de cabines-leito de caminhões semipesados e pesados aos usuários no Brasil, com enfoque nas atividades relacionadas ao habitar, com base na percepção de usuários, na observação da pesquisadora e na avaliação de especialistas. Aspectos socioculturais, comportamentais, necessidades e hábitos dos usuários brasileiros em relação às cabines-leito, bem como adaptações e customizações realizadas para adequá-las às atividades ali realizadas, foram levantados em campo, por meio de observação e registros de imagens de vinte e cinco cabines-leito em uso, bem como entrevistas semiestruturadas com seus usuários. Os levantamentos foram realizados em locais de parada e concentração de caminhões nos estados de São Paulo e Pernambuco e contemplaram caminhões provenientes das regiões Sudeste, Sul, Nordeste e Centro-Oeste. Foram realizadas entrevistas semiestruturadas com seis especialistas de empresas fabricantes de caminhões, com o objetivo de investigar como é avaliada por eles a adequação de cabines-leito desenvolvidas para o mercado global ao contexto e aos usuários no Brasil, bem como os métodos de pesquisa com usuários utilizados no desenvolvimento de cabines-leito nas principais empresas. Foram entrevistados também dois profissionais de empresas que realizam adaptações e customizações dos interiores de cabines-leito. O objetivo geral desta tese é apresentar aspectos relevantes sobre o uso de interiores de cabines-leito de caminhões semipesados e pesados no Brasil como habitações temporárias. Pretende-se, assim, fornecer contribuições e parâmetros para o desenvolvimento de cabines-leito de caminhões que atendam às necessidades dos usuários no contexto brasileiro. / This thesis presents relevant aspects that emerged from qualitative research, with a phenomenological and observational approach, on the suitability of the interior design of sleeper cabins in semi-heavy and heavy trucks to users in Brazil, focusing on activities related to their living based on user perception, in observation of the researcher and expert evaluation. Socio-cultural and behavioral aspects, needs and habits of Brazilian users in relation to sleeper cabins, as well as adjustments and customizations made to suit the activities carried out by such users, were raised in the research field through observation and records of twenty-five sleeper cabins in use, as well as semistructured interviews with their users. The surveys were conducted at rest areas and truck stops in the States of São Paulo and Pernambuco and included trucks traveling from the Southeastern, Southern, Northeastern and Midwestern regions. Semistructured interviews were conducted with six truck manufacturer experts aiming at investigating how they evaluate the adequacy of sleeper cabins designed for the global market context and for users in Brazil, as well as the user research methods used in the development of sleeper cabins in major companies. Two professionals from companies that perform adjustments and customizations of the interior of sleeper cabins were also interviewed. The general objective of this thesis is to present relevant aspects on the use of sleeper cabin interiors in semi-heavy and heavy trucks in Brazil as temporary housing. Hence, it aims at providing contributions and parameters for the development of truck sleeper cabins that meet the needs of users in the Brazilian context.
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Análise de anfetamina, cocaína e tetrahidrocanabinol em fluido oral de motoristas de caminhão que trafegam em rodovias do estado de São Paulo / Analysis of amphetamine, cocaine and cannabis in oral fluid from truck drivers driving through highways in the state of Sao PauloBombana, Henrique Silva 13 December 2016 (has links)
No Brasil, em 2014, os acidentes de trânsito contabilizaram mais de 44 mil óbitos. Já foi relatado na literatura científica a relação entre o uso de drogas por motoristas de caminhão a fim de manterem a exaustiva jornada de trabalho a que são submetidos. O presente estudo teve como objetivo avaliar a frequência do uso de drogas ilícitas por motoristas de caminhão através de análises toxicológicas em amostras de fluido oral. Motoristas de caminhão foram abordados de forma aleatória por policiais rodoviários federais e convidados a participar dos Comandos de Saúde nas Rodovias, evento de promoção à saúde dos caminhoneiros. Os motoristas que aceitaram participar do estudo doaram uma amostra de fluido oral, coletado com o dispositivo Quantisal(TM), e responderam a um questionário estruturado para coleta de dados sociodemográficos. As amostras de fluido oral foram submetidas à análise de triagem para cocaína, anfetamina e delta9-tetrahidrocanabinol (delta9-THC) por ELISA, sendo esse estudo pioneiro na utilização dessa técnica para triagem de amostras de fluido oral no trânsito. As amostras que apresentaram resultados positivos foram confirmadas por cromatografia gasosa acoplada à espectrometria de massas (GC-MS). No período de desenvolvimento desse estudo foi possível o envio das amostras positivas na etapa de triagem para o Instituto Norueguês de Saúde Pública para confirmação por cromatografia líquida de ultra eficiência acoplada à espectrometria de massas em tandem (UPLC-MS/MS). Além das três substâncias já pesquisadas no estudo foram analisadas a presença de outras 29, dentre drogas ilícitas e medicamentos psicoativos. Foram incluídos 762 motoristas. Das amostras analisadas, 5,2% (n=40) apresentaram resultado positivo para algum tipo das drogas estudadas. A cocaína foi a droga mais encontrada (n=16), seguida pela anfetamina (n=11) e delta9-THC (n=4). Ainda, três amostras apresentaram resultados positivos para cocaína e ?9-THC e uma amostra para cocaína e anfetamina. Além da cocaína, anfetamina e ?9-THC, com a confirmação por UPLC-MS/MS foram detectados outros fármacos psicoativos, o meprobamato e o alprazolam, (duas amostras testaram positivo para anfetamina e meprobamato uma para anfetamina e alprazolam e outra amostra para cocaína e meprobamato). Os motoristas com amostras positivas eram mais jovens, com menos escolaridade, mais inexperientes, possuíam uma jornada de trabalho mais extensa e percorriam percursos mais longos. Esse fato alerta, sem dúvida, a necessidade da ampliação de estudos nacionais sobre o uso de substâncias psicoativas, incluindo as ilícitas e medicamentos, para melhor entendimento na comunidade científica e permitindo a implementação de políticas públicas voltadas à prevenção e fiscalização do uso dessas substâncias, com o objetivo de reduzir a morbimortalidade resultante dos acidentes de trânsito nacionais / In Brazil, in 2014 it caused more than 44 thousand deaths. In Brazil is already described in the literature the use of psychoactive substances by truck drivers to maintain their extensive work schedule and stay awake for several hours. Important highways cross through Sao Paulo to other regions from Brazil and to countries from Latin America. This study aims to demonstrate the prevalence of illicit drug use by truck drivers on the State of Sao Paulo through toxicological analyses on oral fluid. Truck drivers were randomly stopped by police officers on federal roads during morning hours. Oral fluid samples were collected using the Quantisal(TM) device. In addition, a questionnaire concerning sociodemographic characteristics and health information was administered. Oral fluid samples were screened for amphetamine, cocaine, and tetrahydrocannabinol (?9-THC) by ELISA. The samples were confirmed by GC-MS, using validated methods for the substances of interest. During the development of this study we had the opportunity to send the positive samples to the Norwegian Institute of Public Health for confirmation using UPLC-MS/MS. Besides cocaine, amphetamine and delta9-THC the samples were tested for others 29 samples, including illicit drugs and psychoactive medicines. 762 drivers agreed to participate. Of the total samples 5.2% (n = 40) tested positive for drugs. Cocaine was the most found drug (n = 16), followed by amphetamine (n = 11) and delta9-THC (n = 4). Furthermore, three samples tested positive for cocaine and delta9-THC and one sample for cocaine and amphetamine. The confirmation using UPLC-MS/MS pointed another two substances that were not tested previously, meprobamate and alprazolam (two samples tested positive for amphetamine and meprobamate, one for amphetamine and alprazolam and another one for cocaine and meprobamate). Drivers presenting positive samples were younger, with less education, less experienced, had a longer work schedule and drove longer distances. This fact shows that, undoubtedly, there is need for more national studies regarding the use of psychoactive substances, illicit and medicines, for a better understand by the scientific community and those responsible for implementation of public policies aiming the control of the use of these substances, in order to, one day, we were able to indeed reduce traffic accidents mortality in our country
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Método de detecção automática de eixos de caminhões baseado em imagens / Truck axle detection automatic method based on imagesPanice, Natália Ribeiro 13 September 2018 (has links)
A presente pesquisa tem por objetivo desenvolver um sistema automático de detecção de eixos de caminhões a partir de imagens. Para isso, são apresentados dois sistemas automáticos: o primeiro para extração de imagens de caminhões a partir de filmagens de tráfego rodoviário feitas em seis locais de uma mesma rodovia situada no Estado de São Paulo, e o segundo, para detecção dos eixos dos caminhões nas imagens. Ambos os sistemas foram fundamentados em conceitos de Processamento de Imagens e Visão Computacional e o desenvolvimento foi feito utilizando programação em linguagem Python e as bibliotecas OpenCV e SciKit. O salvamento automático das imagens de caminhões foi necessário para a construção do banco de imagens utilizado no outro método: a detecção dos eixos dos veículos identificados. Neste estágio foram realizadas a segmentação da imagem do caminhão, a detecção propriamente dita e a classificação dos eixos. Na segmentação dos veículos, utilizou-se as técnicas de limiarização adaptativa seguida de morfologia matemática e em outra ocasião, o descritor de texturas LBP; enquanto na detecção, a Transformada de Hough. Da análise de desempenho desses métodos, a taxa de salvamento das imagens foi 69,2% considerando todos os caminhões que se enquadraram nos frames. Com relação às detecções, a segmentação das imagens dos caminhões feita utilizando limiarização adaptativa com morfologia matemática ofereceu resultados de 57,7% da detecção do total de eixos dos caminhões e 65,6% de falsas detecções. A técnica LBP forneceu, para os mesmos casos, respectivamente, 68,3% e 84,2%. O excesso de detecção foi um ponto negativo dos resultados e pode ser relacionado aos problemas do ambiente externo, geralmente intrínsecos às cenas de tráfego de veículos. Dois fatores que interferiram de maneira significativa foram a iluminação e a movimentação das folhas e galhos das árvores devido ao vento. Desconsiderando esse inconveniente, derivado dos fatores recém citados, as taxas de acerto dos dois tipos de segmentação aumentariam para 90,4% e 93,5%, respectivamente, e as falsas detecções mudariam para 66,5% e 54,7%. Desse modo, os dois sistemas propostos podem ser considerados promissores para o objetivo proposto. / This research aims to develop an automatic truck axle detection system using images. Two automatic systems are presented: one for the extraction of truck images from road videos recorded in a São Paulo state highway and one for the axle detection on images. Both systems are based on Image Processing and Computational Vision techniques, with using programming in Python and OpenCV and SciKit libraries. The truck image extraction system was necessary for the creation of image base, to be used on the axle detection system. Thereunto, image segmentation, axle detection and classification on images were made. In segmentation was used adaptive threshold technique, followed by mathematical morphology and on another time, LBP texture descriptors; for detection, was used Hough Transform. Performance analysis on these methods wielded 69.2% on image save rate, on trucks entirely framed on the image. About axle detection, the truck image segmentation using a combination of adaptive threshold and mathematical morphology wielded 57.7% on axle detection, whilst achieving 65.6% of false detection. Using LBP wielded, on the same images, 68.3% on axle detection and 84.2% of false detection. These excesses was a negative result and can be related to intrinsic issues on the external road traffic environment. Two main factors affected the result: lighting condition changes and the movement of tree leaves and branches. Disregarding these two factors, the proposed system had 90.4% axle truck detection rate using adaptive threshold and mathematical morphology and 93.5% using LBP, and the false detection, changed for 66.5% e 54.7%. Thus, both proposed systems are considered promising.
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Augmented Framework for Economic Viability-Based Powertrain Design and Emissions Analysis of Medium/Heavy-Duty Plug-in Hybrid Electric VehiclesVaidehi Y. Hoshing (5929763) 17 January 2019 (has links)
<div>Plug-in hybrid electric vehicles (PHEVs) are being considered as an alternative to conventional medium-duty (MD) and heavy-duty (HD) commercial vehicles to reduce fuel consumption and tailpipe emissions. Lithium ion batteries, which are used in PHEVs due to their high energy density, are expensive. The battery contributes significantly towards the life-cycle cost of MD/HD PHEVs, as these vehicles, due to high mass and aggressive battery usage, require multiple battery replacements over their lifetime. Smaller batteries increase the fuel consumption and need more replacements, while bigger batteries increase the initial system cost. Powertrain design from a life-cycle cost perspective is required to explore this trade-off and maximize the economic gains obtained from PHEVs. </div><div><br></div><div>Powertrain design entails component sizing, control strategy selection as well as architecture selection. Different powertrain designs yield different lifetime economic gains. A variety of applications exist for MD/HD vehicles, which differ in their ways of powertrain usage, due to variations in required acceleration, available braking, and average and maximum speeds. Therefore, different powertrain designs are needed depending on the application and usage scenario. The powertrain design space needs to be explored, and solutions that maximize the economic gains within the specified constraints need to be chosen.</div><div><br></div><div>This dissertation compares the economic viability of two PHEV applications (MD Truck and HD Transit Bus), with options of series and parallel hybrid architectures, over multiple drivecycles, for four economic scenarios (years 2015, 2020, 2025 and 2030). It is shown that hybridizing the transit bus achieves payback sooner than hybridizing the truck. Further, the results for the transit bus application, over the Manhattan drivecycle, show that implementation of the parallel architecture is economically viable in the 2015(present) scenario, while the series architecture becomes viable in 2020, due to significantly lower initial costs involved in the parallel architecture.</div><div><br></div><div>A methodology to select a solution out of the explored design space that maximizes the economic gains is demonstrated. Variations in the economic and vehicle usage conditions for which this solution is designed, can be expected. It is therefore necessary to check the robustness of this solution to change in external factors such as vehicle mass, annual vehicle miles travelled (AVMT), component and fuel costs. It is shown that the economic gains are affected by the battery cost, fuel cost, AVMT and vehicle mass, while the number of battery replacements are affected by AVMT and vehicle mass. </div><div><br></div><div>A probability-based approach is demonstrated to obtain confidence in the economic and battery life predictions. Specifically, probability-based variations are provided to variables such as miles traveled between recharge, recharge C-rate and battery temperature. It is shown that battery life is affected the most by battery temperature.</div><div><br></div><div>A battery heating/cooling system is required to maintain constant battery temperature of operation during all seasons, but these systems incur additional fuel costs. A framework that utilizes just the Coefficient of Performance (COP) of the heating/cooling system to calculate the excess fuel cost is proposed and demonstrated. An increase of 0.9-1.8\% in fuel consumption is shown, depending on the drivecycle and ambient temperature.</div><div><br></div><div>Further, the well-to-wheel (WTW) fuel-cycle emissions from conventional and PHEV transit buses operating in Indiana and California are assessed using the ``Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation'' (GREET) Model 2017, developed by Argonne National Labs. It is shown that 59% and 63% greenhouse gas (GHG) reductions can be achieved in Indiana and California respectively, along with reduction in carbon monoxide (CO), nitrogen oxides NOx, particulate matter with diameter less than 2.5 microns PM2.5 and volatile organic compounds (VOC) emissions for both the states. However, an increase in sulfur oxides SOx emissions for both the states, and particulate matter with diameter less than 10 microns PM10 increase for Indiana, are observed. </div><div><br></div>
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Avaliação do impacto da medida de desempenho no equivalente veicular de caminhões / Evaluation the use of measure of impedance in the passenger-car equivalents for tucksAndré Luiz Barbosa Nunes da Cunha 11 October 2007 (has links)
Esta pesquisa avaliou o efeito do uso de uma medida de desempenho alternativa à densidade no cálculo dos fatores de equivalência para caminhões típicos em rodovias de pista dupla do estado de São Paulo. A medida de desempenho investigada foi a velocidade dos automóveis e os fatores de equivalência foram calculados pelo método do equivalente médio, que considera mais de um tipo de caminhão na corrente de tráfego, representa melhor a interação entre caminhões e permite o uso de simulação de tráfego para determinação dos equivalentes. Como este método de cálculo considera uma composição fixa de caminhões, o tráfego de caminhões em rodovias paulistas de pista dupla foi caracterizado em função de dois aspectos: (1) o fluxo veicular em dias úteis típicos e (2) o desempenho das configurações de caminhões, a partir da relação massa/potência. O modelo de simulação utilizado nesta pesquisa foi o CORSIM, o mesmo modelo usado no HCM-2000. Para tanto, o CORSIM foi calibrado para as condições observadas em rodovias paulistas de pista dupla. A calibração foi realizada em duas etapas, ambas baseadas em algoritmos genéticos: a primeira etapa focou no modelo de locomoção dos caminhões, resultando erros médios da ordem de 5%; a segunda visou à lógica de car-following, que define o comportamento dos motoristas. A versão calibrada do CORSIM para as condições paulistas apresentou erros médios de 6,32% na calibração e de 6,58% na validação. Os equivalentes veiculares foram calculados para diferentes magnitudes de greides, comprimentos de rampas, porcentagens de caminhões, velocidade de fluxo livre e níveis de serviço, tanto para a velocidade dos automóveis como para a densidade. Como resultado final, observou-se que o uso da velocidade dos automóveis como medida de desempenho implica em equivalentes veiculares muito elevados. Desta forma, a capacidade de tráfego e o nível de serviço estimado utilizando estes equivalentes foram piores do que utilizando os equivalentes veiculares obtidos com a densidade como medida de desempenho. / The objective of this research was to evaluate the use of a measure of impedance alternative to density to obtain passenger-car equivalence factors for typical trucks on multilane highways in the state of São Paulo. The impedance investigated was the passenger-car speed, and the equivalence factors were obtained through the average equivalent method since it considers different types of trucks within the traffic flow, is capable to represent interactions among trucks adequately, and allow the use of traffic simulation. Since the estimation method employed is based on a fixed truck population, the truck flow on multilane highways in the state of São Paulo was characterized based on two aspects: (1) a typical traffic flow, considering the traffic flow on typical weekdays, (2) the truck performance based on mass/power ratio. The simulation model employed was CORSIM, the same model used in the HCM-2000, and it was calibrated for the conditions observed in multilane highways in the state of São Paulo. The calibration was carried out using genetic algorithms and involved two steps. The first one focused on the truck motion model and produced average errors around 5%. The second one focused on the car-following logic that defines the drivers\' behavior. The CORSIM calibrated for the state of São Paulo highways produced average errors of 6.32% at the calibration stage and average errors of 6.58% at the validation stage. Passenger-car equivalents were calculated for different grade levels, grade lengths, trucks percentages, free-flow speeds and leves of service using passenger-car speed and density as the impedance measure. It was observed that, when compared to density, the use of passenger-car speed as a measure of impedance results in higher values for the equivalence factors. It means smaller capacities and worse estimates for level of service.
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Avaliação do impacto da medida de desempenho no equivalente veicular de caminhões / Evaluation the use of measure of impedance in the passenger-car equivalents for tucksCunha, André Luiz Barbosa Nunes da 11 October 2007 (has links)
Esta pesquisa avaliou o efeito do uso de uma medida de desempenho alternativa à densidade no cálculo dos fatores de equivalência para caminhões típicos em rodovias de pista dupla do estado de São Paulo. A medida de desempenho investigada foi a velocidade dos automóveis e os fatores de equivalência foram calculados pelo método do equivalente médio, que considera mais de um tipo de caminhão na corrente de tráfego, representa melhor a interação entre caminhões e permite o uso de simulação de tráfego para determinação dos equivalentes. Como este método de cálculo considera uma composição fixa de caminhões, o tráfego de caminhões em rodovias paulistas de pista dupla foi caracterizado em função de dois aspectos: (1) o fluxo veicular em dias úteis típicos e (2) o desempenho das configurações de caminhões, a partir da relação massa/potência. O modelo de simulação utilizado nesta pesquisa foi o CORSIM, o mesmo modelo usado no HCM-2000. Para tanto, o CORSIM foi calibrado para as condições observadas em rodovias paulistas de pista dupla. A calibração foi realizada em duas etapas, ambas baseadas em algoritmos genéticos: a primeira etapa focou no modelo de locomoção dos caminhões, resultando erros médios da ordem de 5%; a segunda visou à lógica de car-following, que define o comportamento dos motoristas. A versão calibrada do CORSIM para as condições paulistas apresentou erros médios de 6,32% na calibração e de 6,58% na validação. Os equivalentes veiculares foram calculados para diferentes magnitudes de greides, comprimentos de rampas, porcentagens de caminhões, velocidade de fluxo livre e níveis de serviço, tanto para a velocidade dos automóveis como para a densidade. Como resultado final, observou-se que o uso da velocidade dos automóveis como medida de desempenho implica em equivalentes veiculares muito elevados. Desta forma, a capacidade de tráfego e o nível de serviço estimado utilizando estes equivalentes foram piores do que utilizando os equivalentes veiculares obtidos com a densidade como medida de desempenho. / The objective of this research was to evaluate the use of a measure of impedance alternative to density to obtain passenger-car equivalence factors for typical trucks on multilane highways in the state of São Paulo. The impedance investigated was the passenger-car speed, and the equivalence factors were obtained through the average equivalent method since it considers different types of trucks within the traffic flow, is capable to represent interactions among trucks adequately, and allow the use of traffic simulation. Since the estimation method employed is based on a fixed truck population, the truck flow on multilane highways in the state of São Paulo was characterized based on two aspects: (1) a typical traffic flow, considering the traffic flow on typical weekdays, (2) the truck performance based on mass/power ratio. The simulation model employed was CORSIM, the same model used in the HCM-2000, and it was calibrated for the conditions observed in multilane highways in the state of São Paulo. The calibration was carried out using genetic algorithms and involved two steps. The first one focused on the truck motion model and produced average errors around 5%. The second one focused on the car-following logic that defines the drivers\' behavior. The CORSIM calibrated for the state of São Paulo highways produced average errors of 6.32% at the calibration stage and average errors of 6.58% at the validation stage. Passenger-car equivalents were calculated for different grade levels, grade lengths, trucks percentages, free-flow speeds and leves of service using passenger-car speed and density as the impedance measure. It was observed that, when compared to density, the use of passenger-car speed as a measure of impedance results in higher values for the equivalence factors. It means smaller capacities and worse estimates for level of service.
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An Analysis of Household Vehicle Ownership and Utilization Patterns in the United States Using the 2001 National Household Travel SurveyPinjari, Abdul Rawoof 01 April 2004 (has links)
Vehicle ownership and utilization have a profound influence on activity-travel patterns of individuals, vehicle emissions, fuel consumption, highway capacity, congestion and traffic safety. The influence could be further skewed by the diversity of the vehicle fleet. This thesis presents a detailed analysis of the 2001 National Household Travel Survey data to understand the vehicle ownership patterns, fleet mix, allocation and utilization in the context of household and person socio-demographic characteristics. Along with a rich descriptive analysis, models of vehicle ownership and utilization are estimated to distinguish four vehicle types; cars, SUVs (sport utility vehicles), vans and pickup trucks based on their ownership by households and utilization patterns by household members. The primary driver level vehicle utilization analysis provides insights into the extent of allocation of a vehicle to a single person. In addition to confirming many perceptions about the ownership, acquisition and utilization patterns of different types of vehicles, this analysis brings out some subtle differences and similarities among the vehicle types. The analysis results indicate a greater propensity to acquire and use larger vehicles such as minivans, sports utility vehicles and pickup trucks among certain socio-demographic segments of population. Increased ownership and use of vans and SUVs, and their usage as personal vehicles rather than just work vehicles warrants a need to revise vehicle type specific policies, transportation planning and control measures.
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Collision Avoidance Systems for Mine Haul Trucks and Unambiguous Dynamic Real Time Single Object DetectionGlynn, Patrick Joseph, n/a January 2005 (has links)
A suite of new collision avoidance systems (CAS) is presented for use in heavy vehicles whose structure and size necessarily impede driver visibility is introduced. The main goal of the project is to determine the appropriate use of each of the commercially available technologies and, where possible, produce a low cost variant suitable for use in proximity detection on large mining industry haul trucks. CAS variants produced were subjected to a field demonstration and, linked to the output from the earlier CAS 1 project, (a production high-definition in-cabin video monitor and r/f tagging system). The CAS 2 system used low cost Doppler continuous wave radar antennae coupled to the CAS 1 monitor to indicate the presence of an object moving at any speed above 3 Km/h relative to the antennae. The novelty of the CAS 3 system lies in the design of 3 interconnected, modules. The modules are 8 radar antennae (as used in CAS 2) modules located on the truck, software to interface with the end user (i.e. the drivers of the trucks) and a display unit. Modularisation enables the components to be independently tested, evaluated and replaced when in use. The radar antennae modules and the system as a whole are described together with the empirical tests conducted and results obtained. The tests, drawing on Monte-Carlo simulation techniques, demonstrate both the 'correctness' of the implementations and the effectiveness of the system. The results of the testing of the final prototype unit were highly successful both as a computer simulation level and in practical tests on light vehicles. A number of points, (as a consequence of the field test), are reviewed and their application to future projects discussed.
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