Esse trabalho fornece uma descrição detalhada sobre os fenômenos da dinâmica veicular que influenciam no ride, desde os modos de vibrar de massa suspensa até os modos de vibrar com a presença de flexibilidade do chassi. Alguns itens desta descrição servem como esclarecimento de aspectos raramente encontrados na literatura. O potencial de representação dos modelos simplificados, com poucos graus de liberdade, foi explorado exaustivamente. O entendimento obtido com esses modelos, em conjunto com os procedimentos atuais de avaliação de conforto, possibilitou a análise das métricas atuais relativas ao ride e a definição de novas métricas mais adequadas para esse tipo de avaliação. A teoria apresentada nesse trabalho foi ilustrada através de exemplos reais com medições experimentais e simulações computacionais de veículos de produção da Ford Motor Company. / Using simplified mathematical models this work presents a detailed description of vehicle characteristics that significantly influence ride evaluation. These simple modes were used in order to describe basic vehicle modes of vibration, such as bounce, pitch and unsprung mass ones. The influence of modes of vibration with frame flexibility was also presented by means of a full vehicle model. These models were used in order to evaluate current ride metrics and to propose new ones. These new metrics seemed to better correlate with subjective evaluation and with the standards used for comfort evaluation. The theory described in this work was illustrated by experimental results of Ford Motor Company vehicles.

A dissertação tem como objetivo a análise das viagens e das características dos usuários que dirigem automóvel até as estações do sistema de transporte coletivo de alta capacidade, na qual embarcam e prosseguem viagem por motivo trabalho de metrô ou trem. Estuda-se a relação deste tipo de viagem com a acessibilidade ao centro das cidades e com a política e a qualidade de estacionamento para os automóveis junto às estações e no local de trabalho. Através de pesquisas sobre viagens da Região Metropolitana de São Paulo obteve-se dados sobre estas viagens, conhecidas como park and ride, no metrô e nos trens metropolitanos. Foram levantadas as principais zonas de origem e destinos das viagens park and ride, e as estações de trem e metrô com transferências significativas destas viagens, bem como analisados estudos e informações sobre características de estacionamento em estações, padrão das viagens e o perfil do usuário que faz esta troca modal. Analisa-se o comportamento do usuário como objeto de modelagem na sua escolha entre ir direto de automóvel ao trabalho ou ir até a estação dirigindo automóvel e completar a viagem ao trabalho de metrô. Investigam-se estas viagens através da construção de um modelo de escolha discreta baseado na teoria da utilidade aleatória, cujas variáveis são a diferença de tempo de viagem, a diferença de preço de estacionamento e a qualidade do estacionamento junto à estação. Propõe-se um modelo logit binomial e realiza-se um uma pesquisa com usuários do metrô, em um estacionamento de automóveis junto à Estação Tietê, que inclui questões sobre preferência declarada. Com os resultados das entrevistas se faz a calibração e análise comparativa de modelos para simulação da escolha da viagem. Verifica-se que a influência da diferença de tempo entre as viagens tem mais influência que a diferença de preço entre os estacionamentos no centro e junto a estação, na escolha do modo de transporte pelos entrevistados. Nota-se que a qualidade de estacionamento entendida como maior quando localizado dentro da estação e menor quando fora é significativa, provavelmente por proporcionar ao usuário além de economia de tempo, mais comodidade e segurança. / The objective of this dissertation is the analysis of characteristics of trips and users, who drive a car to the stations of the high capacity passenger transport system, in which they embark and continue the trip to their work place. It studies this type of trip related to the accessibility to downtown and to the quality of car parking facilities next to the stations and at the work place. The survey transport data within the Metropolitan Region of San Paulo presents information about these trips, known as Park and Ride, in the subway lines and in the commuter train lines. The main zones of origin and destination of the Park and Ride trips were identified and the stations of train and subway with significant transferences too. The characteristics of parking in stations and the trips patterns of users making this modal transfer were studied. The user\'s behavior was analyzed in order to modeling his choice between going direct by car to the work place or going by car to the station and take the subway to the work place. A discrete choice model was proposed based in the random utility theory. The variables considered are the difference in trip time, the difference of parking price and the quality of the parking next to the station. A Binomial Logit Model was considered and a stated preference survey was conceived. A case study was conducted with the interview of users at a car parking lot next to the subway Tiete Station. The results of the interviews were used to calibrate and compare the discrete choice models tested. It was verified that the difference of time between the alternatives is more important than the difference of parking price in the transport choice. It was also verified that quality is significant to users, and it is seen higher when the parking is in the station. This is due, probably, to time savings and both comfort and safety.

Atualmente, a utilização de suspensão traseira do tipo twist beam é muito difundida em veículos de pequeno porte e alto volume de produção, por apresentar um bom compromisso entre custo e desempenho. No entanto este conceito possui limitações no que diz respeito à absorção de vibrações de ride (conforto) secundário e impactos, e possui um compromisso com as características de handling (estabilidade) do veículo. Este trabalho apresenta um estudo de influência da rigidez das buchas da suspensão twist beam nos eventos de impacto singular para ride e no regime permanente do handling. É utilizado no estudo um modelo de multicorpos com veículo completo construído no software ADAMS. Para o estudo de ride é utilizada uma abordagem semi-analítica, através dos dados de medição em pista utilizando transdutores de força nas rodas (WFT). A partir do uso de tais carregamentos é possível simular os fenômenos de ride sem necessitar de um modelo específico de pneu. Para o estudo de handling é utilizado modelo pneu correlacionado com medição de curva em uma bancada chamada Flat-Trac. Utilizando os modelos construídos para ride e handling, são apresentados os dados de correlação dos modelos com veículo protótipo e um estudo da influência da rigidez de bucha nas métricas de impacto singular para ride e gradiente de esterçamento para handling. / Currently, the use of rear suspension twist beam is widespread in small vehicles and high-volume production, because it presents a good compromise between cost and performance. However, this concept has limitations regards the absorption of secondary ride vibrations and impacts, and has a commitment with handling characteristics of the vehicle. This dissertation presents a study of the stiffness influence of the twist beam suspension bushings in impact singular events to the ride and the steady state handling behavior. A multibody model of vehicle complete built in ADAMS software has been used for the study. For the ride study is using a semi-analytical approach, through the track measurement data using wheel force transducers (WFT). From the use of such road loads is possible to simulate the ride phenomena without needing a specific model of tire. For the handling study a tire model used is correlated with measurement curve on a workbench called Flat-Trac. Using models built for ride and handling are shown the correlation data models with prototype vehicle and a study of the influence of the bushing stiffness for the singular impact event metrics for ride and the steering gradient metric for handling.

Large off-shore wind farms raise the concern of widespread tripping of off-shore wind generator in the presence of system faults and corresponding voltage dips that could potentially cause system wide blackout. In this thesis an offshore wind farm and three different types of power transmission are modeled and studied using simulation software. Off-shore wind farm composed of fixed speed induction generators and HVAC interconnection, HVAC interconnection plus STATCOM and HVDC interconnections are studied. Onshore grid faults are simulated for each interconnection. Voltage tolerance curves are established to assess fault ride through capability of each interconnection and compared with different grid transmission ride through capacity required by grid operator.

When introducing autonomous functionality in personal vehicles the ability to control the quality of the ride is transferred from the driver to the vehicle control system. In this context, a reference method for quantifying ride quality may be a useful tool in the development and tuning process. This master’s thesis investigates whether general quantitative measures of ride quality can be of value in the tuning of motion controllers for autonomous vehicles. A set of tools is built for a specific case study, analysing a lateral path planning algorithm, based on a finite horizon linear quadratic tracking controller, and how its tuning affects ride quality performance. A graphical user interface is built, with functionality for frequency domainanalysis of the path planning algorithm, individually and in combination with the remaining lateral control system, as well as ride quality evaluation based on lateral acceleration data, from logged test runs and simulation results. In addition, a simulation environment for the lateral control system is modified to be used in combination with the evaluation tool. Results of the case study indicate a measurable difference in ride quality performance when comparing manual and autonomous driving with the current implementation. Attempts were made to improve ride quality by re-tuning the path planning algorithm but little or no improvement from the previous tuning was made. The work has recognized the potential of using ride quality measures in the development and tuning process for autonomous vehicles as well as devising a tuning strategy incorporating frequency analysis and ride quality evaluation through simulation for the lateral control system. To further increase ride quality performance via the path planning algorithm an altered controller structure, such as a frequency weighted linear quadratic controller is suggested.

A dissertação tem como objetivo a análise das viagens e das características dos usuários que dirigem automóvel até as estações do sistema de transporte coletivo de alta capacidade, na qual embarcam e prosseguem viagem por motivo trabalho de metrô ou trem. Estuda-se a relação deste tipo de viagem com a acessibilidade ao centro das cidades e com a política e a qualidade de estacionamento para os automóveis junto às estações e no local de trabalho. Através de pesquisas sobre viagens da Região Metropolitana de São Paulo obteve-se dados sobre estas viagens, conhecidas como park and ride, no metrô e nos trens metropolitanos. Foram levantadas as principais zonas de origem e destinos das viagens park and ride, e as estações de trem e metrô com transferências significativas destas viagens, bem como analisados estudos e informações sobre características de estacionamento em estações, padrão das viagens e o perfil do usuário que faz esta troca modal. Analisa-se o comportamento do usuário como objeto de modelagem na sua escolha entre ir direto de automóvel ao trabalho ou ir até a estação dirigindo automóvel e completar a viagem ao trabalho de metrô. Investigam-se estas viagens através da construção de um modelo de escolha discreta baseado na teoria da utilidade aleatória, cujas variáveis são a diferença de tempo de viagem, a diferença de preço de estacionamento e a qualidade do estacionamento junto à estação. Propõe-se um modelo logit binomial e realiza-se um uma pesquisa com usuários do metrô, em um estacionamento de automóveis junto à Estação Tietê, que inclui questões sobre preferência declarada. Com os resultados das entrevistas se faz a calibração e análise comparativa de modelos para simulação da escolha da viagem. Verifica-se que a influência da diferença de tempo entre as viagens tem mais influência que a diferença de preço entre os estacionamentos no centro e junto a estação, na escolha do modo de transporte pelos entrevistados. Nota-se que a qualidade de estacionamento entendida como maior quando localizado dentro da estação e menor quando fora é significativa, provavelmente por proporcionar ao usuário além de economia de tempo, mais comodidade e segurança. / The objective of this dissertation is the analysis of characteristics of trips and users, who drive a car to the stations of the high capacity passenger transport system, in which they embark and continue the trip to their work place. It studies this type of trip related to the accessibility to downtown and to the quality of car parking facilities next to the stations and at the work place. The survey transport data within the Metropolitan Region of San Paulo presents information about these trips, known as Park and Ride, in the subway lines and in the commuter train lines. The main zones of origin and destination of the Park and Ride trips were identified and the stations of train and subway with significant transferences too. The characteristics of parking in stations and the trips patterns of users making this modal transfer were studied. The user\'s behavior was analyzed in order to modeling his choice between going direct by car to the work place or going by car to the station and take the subway to the work place. A discrete choice model was proposed based in the random utility theory. The variables considered are the difference in trip time, the difference of parking price and the quality of the parking next to the station. A Binomial Logit Model was considered and a stated preference survey was conceived. A case study was conducted with the interview of users at a car parking lot next to the subway Tiete Station. The results of the interviews were used to calibrate and compare the discrete choice models tested. It was verified that the difference of time between the alternatives is more important than the difference of parking price in the transport choice. It was also verified that quality is significant to users, and it is seen higher when the parking is in the station. This is due, probably, to time savings and both comfort and safety.

Esse trabalho fornece uma descrição detalhada sobre os fenômenos da dinâmica veicular que influenciam no ride, desde os modos de vibrar de massa suspensa até os modos de vibrar com a presença de flexibilidade do chassi. Alguns itens desta descrição servem como esclarecimento de aspectos raramente encontrados na literatura. O potencial de representação dos modelos simplificados, com poucos graus de liberdade, foi explorado exaustivamente. O entendimento obtido com esses modelos, em conjunto com os procedimentos atuais de avaliação de conforto, possibilitou a análise das métricas atuais relativas ao ride e a definição de novas métricas mais adequadas para esse tipo de avaliação. A teoria apresentada nesse trabalho foi ilustrada através de exemplos reais com medições experimentais e simulações computacionais de veículos de produção da Ford Motor Company. / Using simplified mathematical models this work presents a detailed description of vehicle characteristics that significantly influence ride evaluation. These simple modes were used in order to describe basic vehicle modes of vibration, such as bounce, pitch and unsprung mass ones. The influence of modes of vibration with frame flexibility was also presented by means of a full vehicle model. These models were used in order to evaluate current ride metrics and to propose new ones. These new metrics seemed to better correlate with subjective evaluation and with the standards used for comfort evaluation. The theory described in this work was illustrated by experimental results of Ford Motor Company vehicles.

In recent years, the paradigm of personal urban mobility has radically evolved as an increasing number of Mobility-on-Demand (MoD) systems continue to revolutionize urban transportation. Hailed as the future of sustainable transportation, with significant implications on urban planning, these systems typically utilize a fleet of shared vehicles such as bikes, electric scooters, cars, etc., and provide a centralized matching platform to deliver point-to-point mobility to passengers. In this dissertation, we study MoD systems along three operational directions – (1) modeling: developing analytical models that capture the rich stochasticity of passenger demand and its impact on the fleet distribution, (2) economics: devising strategies to maximize revenue, and (3) control: developing coordination mechanisms aimed at optimizing platform throughput. First, we focus on the metropolitan bike-sharing systems where platforms typically do not have access to real-time location data to ascertain the exact spatial distribution of their fleet. We formulate the problem of accurately predicting the fleet distribution as a Markov Chain monitoring problem on a graph representation of a city. Specifically, each monitor provides information on the exact number of bikes transitioning to a specific node or traversing a specific edge at a particular time. Under budget constraints on the number of such monitors, we design efficient algorithms to determine appropriate monitoring operations and demonstrate their efficacy over synthetic and real datasets. Second, we focus on the revenue maximization strategies for individual strategic driving partners on ride-hailing platforms. Under the key assumption that large-scale platform dynamics are agnostic to the actions of an individual strategic driver, we propose a series of dynamic programming-based algorithms to devise contingency plans that maximize the expected earnings of a driver. Using robust optimization techniques, we rigorously reason about and analyze the sensitivity of such strategies to perturbations in passenger demand distributions. Finally, we address the problem of large-scale fleet management. Recent approaches for the fleet management problem have leveraged model-free deep reinforcement learning (RL) based algorithms to tackle complex decision-making problems. However, such methods suffer from a lack of explainability and often fail to generalize well. We consider an explicit need-based coordination mechanism to propose a non-deep RL-based algorithm that augments tabular Q-learning with a combinatorial optimization problem. Empirically, a case study on the New York City taxi demand enables a rigorous assessment of the value, robustness, and generalizability of the proposed approaches.

<p>Problems associated with traffic, such as traffic congestionand pollution, have occurred in major urban areas in particulardue to the increased use of cars. One possible way to reducethe use of cars is to replace commuter trips by car with othermodes of transport, such as a combination of car and publictransport called Park&Ride. The aim of this thesis was tounderstand more about factors influencing the choice of modeand to find measures that could attract car drivers to Park&Ride. A stated preference survey has been conducted inorder to quantify some standard factors. The factors used inthis stated choice experiment were: security at the lot,availability of spaces at the parking lot, costs at the parkinglot and walking distances between the parking space and thestation. The results indicate that security at the Park&Ride facility is important. Both sexes assign a high value tosecure parking, but women are more willing to pay for lights atan unguarded parking lot. The results reveal that parkingfacilities, such as free parking and short distance betweenparking place and work at work, influence people’s choiceof mode. A general conclusion is that there is potential forincreasing the use of Park&Ride facilities, especiallyamong women and respondents over 30 years.</p><p><b>Key words:</b>Mode choice, valuation, traffic reduction,stated preference, factors, Park&Ride</p>

Bus-based Park and Ride (P&R) schemes have become increasingly popular over the past 40 years in the UK, as a result of them being considered a positive traffic reduction policy by many, not least local authorities. There have nevertheless been concerns over the true effects of P&R. For instance, surveys of P&R users have long since revealed that up to a third transfer from conventional public transport. This induces car travel for the access portion of the P&R trip, which is generally large compared to the bus portion, owing to the edge-of-town location of P&R sites. Combined with the mileage effects of high-frequency bus services, evidence has suggested that P&R may thus result in an increase, compared to alternative travel behaviour, in the mean vehicle miles travelled (VMT) of its users. This thesis aims to investigate how UK bus-based P&R may be developed to reduce users VMT. As such, it applies to P&R the Characteristics Approach to Consumer Demand and delineates the attributes of interchange from which users derive utility. The research also develops this approach to consider the characteristics that affect the traffic impacts of P&R. The characteristics of P&R are adjusted to provide alternative concepts of interchange that aim to reduce VMT. These concepts are then examined to understand the level of utility that they are likely to provide. Local authorities perceptions of utility are examined initially, through a national survey which also looks at general attitudes towards P&R, its effects and its future. The city of Cambridge (UK) is selected as a case study in which an in-depth document analysis and interview survey of local stakeholders is carried out to understand the role of P&R in local policy and the implications of the implementation of alternative concepts of interchange. In this context, a survey of P&R users is also undertaken which considers the VMT effects of the current and alternative concepts of P&R as well as the change in the level of utility that would be derived from using them. It is concluded that local authorities generally consider P&R to be an effective policy in reducing car use whilst also playing important roles in the local economy and political arena. Yet the evidence on the Cambridge P&R scheme suggests that VMT is increased to a higher degree than previously proven. Alternative concepts of interchange are shown to offer some potentially significant benefits by reducing the VMT of users. Furthermore, some of the alternative concepts are also shown to offer benefits in terms of the utility that they may provide to the user, and the perceptions on this by local authorities. The VMT and utility results are combined to suggest that future implementation of interchange should consider operating feeder bus services into interchange sites (an intermediate solution offering some VMT benefits with relatively small resource requirements) or, operating a series of small interchange sites along main access routes to host cities (likely to require more resources but providing significant VMT benefits).