918 resultados para Tracklaying vehicles
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The time and the distance traveled during the acceleration and the velocity retaking are parameters used for the comparison and the project of vehicles. In this paper equations for the calculation of those parameters are presented. Several criteria are presented for the shift gears. It is also verified the occurrence or not of total slip during the acceleration of the vehicle. The theoretical models were implemented in a developed computational system. Such system was applied in a Mercedes-Benz do Brazil sample vehicle, in order to facilitate comparisons between the simulate values and the experimental road tests. Copyright © 1997 Society of Automotive Engineers, Inc.
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The fuel consumption is an important factor in the vehicle development due the fact that it has a direct effect on its trade aims. Besides that, it is known that the petrol is a scarce fuel. In this paper it is presented a procedure of fuel consumption calculation for a vehicle traveling in driving schedule. In such calculation it has been taken into account the operational conditions (load, pavement, climbing road, among others) and the building characteristics (map engine, transmission, frontal area, tire, among others) of road vehicles. There has also been an application of the theoretical model developed in a sample Mercedes-Benz do Brasil vehicle which has been compared with the values of experimental tests. Copyright © 1997 Society of Automotive Engineers, Inc.
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The main objective of this paper is to make a prospective analysis about the tendencies of the world wide strategies of commercial vehicles development, in relation of the current local and international scenery. It has been done a research by using the Delphi method, which consists into regulate, systematically, the presentation of questions about a specified problem to a group of specialists. In order to guarantee more representative data, it has been adopted three distinct groups: academics, OEMs managers and Tier 1 suppliers managers. The results showed that the three mentioned groups have similar opinion about the necessity of having a product development in the subsidiaries companies; also it has been pointed the necessity of having more taylor made vehicles, due to the intrinsic characteristics of this industry segment. Copyright © 2008 SAE International.
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A multi-agent system with a percolation approach to simulate the driving pattern of Plug-In Electric Vehicle (PEV), especially suited to simulate the PEVs behavior on any distribution systems, is presented. This tool intends to complement information about the driving patterns database on systems where that kind of information is not available. So, this paper aims to provide a framework that is able to work with any kind of technology and load generated of PEVs. The service zone is divided into several sub-zones, each subzone is considered as an independent agent identified with corresponding load level, and their relationships with the neighboring zones are represented as network probabilities. A percolation approach is used to characterize the autonomy of the battery of the PVEs to move through the city. The methodology is tested with data from a mid-size city real distribution system. The result shows the sub-area where the battery of PEVs will need to be recharge and gives the planners of distribution systems the necessary input for a medium to long term network planning in a smart grid environment. © 2012 IEEE.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The retaking of the ethanol program in the year 2003 as a fuel for light road transportation in Brazil through the introduction of flex fuel vehicles fleet was a good strategy to overcome the difficulties of the ethanol production sector and did work to increase its market share relative to gasoline. This process, however, may cause a future disequilibrium on the food production and on the refining oil derivates structure. In order to analyze the substitution process resultant of the competition between two opponents fighting for the same market, in this case the gasoline/ethanol substitution process, a method derived from the biomathematics based on the non-linear differential equations (NLDE) system is utilized. A brief description of the method is presented. Numerical adherence of the method to explain several substitution phenomena that occurred in the past is presented in the previous author`s paper, in which the urban gas pipeline system substitution of bottled LPG in the dwelling sector and the substitution of the urban diesel transportation fleet by compressed natural gas (CNG) buses is presented. The proposed method is particularly suitable for prospective analysis and scenarios assessment. (c) 2008 Elsevier Ltd. All rights reserved.
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A sample of 21 light duty vehicles powered by Otto cycle engines were tested on a chassis dynamometer to measure the exhaust emissions of nitrous oxide (N2O). The tests were performed at the Vehicle Emission Laboratory of CETESB (Environmental Company of the State of Sao Paulo) using the US-FTP-75 (Federal Test Procedure) driving cycle. The sample tested included passenger cars running on three types of fuels used in Brazil: gasohol, ethanol and CNG. The measurement of N2O was made using two methods: Non Dispersive InfraRed (NDIR) analyzer and Fourier Transform InfraRed spectroscopy (FTIR). Measurements of regulated pollutants were also made in order to establish correlations between N2O and NOx. The average N2O emission factors obtained by the NDIR method was 78 +/- 41 mg.km(-1) for vehicles running with gasohol, 73 +/- 45 mg.km(-1) for ethanol vehicles and 171 +/- 69 mg.km(-1) for CNG vehicles. Seventeen results using the FTIR method were also obtained. For gasohol vehicles the results showed a good agreement between the two methods, with an average emission factor of 68 +/- 41 mg.km(-1). The FTIR measurement results of N2O for ethanol and CNG vehicles were much lower than those obtained by the NDIR method. The emission factors were 17 +/- 10 mg.km(-1) and 33 +/- 17 mg.km(-1), respectively, possibly because of the interference of water vapor (present at a higher concentration in the exhaust gases of these vehicles) on measurements by the NDIR method.
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Most of the works published on hydrodynamic parameter identification of open-frame underwater vehicles focus their attention almost exclusively on good coherence between simulated and measured responses, giving less importance to the determination of “actual values” for hydrodynamic parameters. To gain insight into hydrodynamic parameter experimental identification of open-frame underwater vehicles, an experimental identification procedure is proposed here to determine parameters of uncoupled and coupled models. The identification procedure includes: (i) a prior estimation of actual values of the forces/torques applied to the vehicle, (ii) identification of drag parameters from constant velocity tests and (iii) identification of inertia and coupling parameters from oscillatory tests; at this stage, the estimated values of drag parameter obtained in item (ii) are used. The procedure proposed here was used to identify the hydrodynamic parameters of LAURS—an unmanned underwater vehicle developed at the University of São Paulo. The thruster–thruster and thruster–hull interactions and the advance velocity of the vehicle are shown to have a strong impact on the efficiency of thrusters appended to open-frame underwater vehicles, especially for high advance velocities. Results of tests with excitation in 1-DOF and 3-DOF are reported and discussed, showing the feasibility of the developed procedure.
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The present work tries to display a comprehensive and comparative study of the different legal and regulatory problems involved in international securitization transactions. First, an introduction to securitization is provided, with the basic elements of the transaction, followed by the different varieties of it, including dynamic securitization and synthetic securitization structures. Together with this introduction to the intricacies of the structure, a insight into the influence of securitization in the financial and economic crisis of 2007-2009 is provided too; as well as an overview of the process of regulatory competition and cooperation that constitutes the framework for the international aspects of securitization. The next Chapter focuses on the aspects that constitute the foundations of structured finance: the inception of the vehicle, and the transfer of risks associated to the securitized assets, with particular emphasis on the validity of those elements, and how a securitization transaction could be threatened at its root. In this sense, special importance is given to the validity of the trust as an instrument of finance, to the assignment of future receivables or receivables in block, and to the importance of formalities for the validity of corporations, trusts, assignments, etc., and the interaction of such formalities contained in general corporate, trust and assignment law with those contemplated under specific securitization regulations. Then, the next Chapter (III) focuses on creditor protection aspects. As such, we provide some insights on the debate on the capital structure of the firm, and its inadequacy to assess the financial soundness problems inherent to securitization. Then, we proceed to analyze the importance of rules on creditor protection in the context of securitization. The corollary is in the rules in case of insolvency. In this sense, we divide the cases where a party involved in the transaction goes bankrupt, from those where the transaction itself collapses. Finally, we focus on the scenario where a substance over form analysis may compromise some of the elements of the structure (notably the limited liability of the sponsor, and/or the transfer of assets) by means of veil piercing, substantive consolidation, or recharacterization theories. Once these elements have been covered, the next Chapters focus on the regulatory aspects involved in the transaction. Chapter IV is more referred to “market” regulations, i.e. those concerned with information disclosure and other rules (appointment of the indenture trustee, and elaboration of a rating by a rating agency) concerning the offering of asset-backed securities to the public. Chapter V, on the other hand, focuses on “prudential” regulation of the entity entrusted with securitizing assets (the so-called Special Purpose vehicle), and other entities involved in the process. Regarding the SPV, a reference is made to licensing requirements, restriction of activities and governance structures to prevent abuses. Regarding the sponsor of the transaction, a focus is made on provisions on sound originating practices, and the servicing function. Finally, we study accounting and banking regulations, including the Basel I and Basel II Frameworks, which determine the consolidation of the SPV, and the de-recognition of the securitized asset from the originating company’s balance-sheet, as well as the posterior treatment of those assets, in particular by banks. Chapters VI-IX are concerned with liability matters. Chapter VI is an introduction to the different sources of liability. Chapter VII focuses on the liability by the SPV and its management for the information supplied to investors, the management of the asset pool, and the breach of loyalty (or fiduciary) duties. Chapter VIII rather refers to the liability of the originator as a result of such information and statements, but also as a result of inadequate and reckless originating or servicing practices. Chapter IX finally focuses on third parties entrusted with the soundness of the transaction towards the market, the so-called gatekeepers. In this respect, we make special emphasis on the liability of indenture trustees, underwriters and rating agencies. Chapters X and XI focus on the international aspects of securitization. Chapter X contains a conflicts of laws analysis of the different aspects of structured finance. In this respect, a study is made of the laws applicable to the vehicle, to the transfer of risks (either by assignment or by means of derivatives contracts), to liability issues; and a study is also made of the competent jurisdiction (and applicable law) in bankruptcy cases; as well as in cases where a substance-over-form is performed. Then, special attention is also devoted to the role of financial and securities regulations; as well as to their territorial limits, and extraterritoriality problems involved. Chapter XI supplements the prior Chapter, for it analyzes the limits to the States’ exercise of regulatory power by the personal and “market” freedoms included in the US Constitution or the EU Treaties. A reference is also made to the (still insufficient) rules from the WTO Framework, and their significance to the States’ recognition and regulation of securitization transactions.
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Hybrid vehicles represent the future for automakers, since they allow to improve the fuel economy and to reduce the pollutant emissions. A key component of the hybrid powertrain is the Energy Storage System, that determines the ability of the vehicle to store and reuse energy. Though electrified Energy Storage Systems (ESS), based on batteries and ultracapacitors, are a proven technology, Alternative Energy Storage Systems (AESS), based on mechanical, hydraulic and pneumatic devices, are gaining interest because they give the possibility of realizing low-cost mild-hybrid vehicles. Currently, most literature of design methodologies focuses on electric ESS, which are not suitable for AESS design. In this contest, The Ohio State University has developed an Alternative Energy Storage System design methodology. This work focuses on the development of driving cycle analysis methodology that is a key component of Alternative Energy Storage System design procedure. The proposed methodology is based on a statistical approach to analyzing driving schedules that represent the vehicle typical use. Driving data are broken up into power events sequence, namely traction and braking events, and for each of them, energy-related and dynamic metrics are calculated. By means of a clustering process and statistical synthesis methods, statistically-relevant metrics are determined. These metrics define cycle representative braking events. By using these events as inputs for the Alternative Energy Storage System design methodology, different system designs are obtained. Each of them is characterized by attributes, namely system volume and weight. In the last part the work, the designs are evaluated in simulation by introducing and calculating a metric related to the energy conversion efficiency. Finally, the designs are compared accounting for attributes and efficiency values. In order to automate the driving data extraction and synthesis process, a specific script Matlab based has been developed. Results show that the driving cycle analysis methodology, based on the statistical approach, allows to extract and synthesize cycle representative data. The designs based on cycle statistically-relevant metrics are properly sized and have satisfying efficiency values with respect to the expectations. An exception is the design based on the cycle worst-case scenario, corresponding to same approach adopted by the conventional electric ESS design methodologies. In this case, a heavy system with poor efficiency is produced. The proposed new methodology seems to be a valid and consistent support for Alternative Energy Storage System design.
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Hybrid vehicles (HV), comprising a conventional ICE-based powertrain and a secondary energy source, to be converted into mechanical power as well, represent a well-established alternative to substantially reduce both fuel consumption and tailpipe emissions of passenger cars. Several HV architectures are either being studied or already available on market, e.g. Mechanical, Electric, Hydraulic and Pneumatic Hybrid Vehicles. Among the others, Electric (HEV) and Mechanical (HSF-HV) parallel Hybrid configurations are examined throughout this Thesis. To fully exploit the HVs potential, an optimal choice of the hybrid components to be installed must be properly designed, while an effective Supervisory Control must be adopted to coordinate the way the different power sources are managed and how they interact. Real-time controllers can be derived starting from the obtained optimal benchmark results. However, the application of these powerful instruments require a simplified and yet reliable and accurate model of the hybrid vehicle system. This can be a complex task, especially when the complexity of the system grows, i.e. a HSF-HV system assessed in this Thesis. The first task of the following dissertation is to establish the optimal modeling approach for an innovative and promising mechanical hybrid vehicle architecture. It will be shown how the chosen modeling paradigm can affect the goodness and the amount of computational effort of the solution, using an optimization technique based on Dynamic Programming. The second goal concerns the control of pollutant emissions in a parallel Diesel-HEV. The emissions level obtained under real world driving conditions is substantially higher than the usual result obtained in a homologation cycle. For this reason, an on-line control strategy capable of guaranteeing the respect of the desired emissions level, while minimizing fuel consumption and avoiding excessive battery depletion is the target of the corresponding section of the Thesis.
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In questa tesi mi occupo di spiegare come si comportano i veicoli autonomi per prendere tutte le decisioni e come i dati dei sensori di ogni auto vengono condivisi con la flotta di veicoli
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We developed UAVNet, a framework for the autonomous deployment of a flying Wireless Mesh Network using small quadrocopter-based Unmanned Aerial Vehicles (UAVs). The flying wireless mesh nodes are automatically interconnected to each other and building an IEEE 802.11s wireless mesh network. The implemented UAVNet prototype is able to autonomously interconnect two end systems by setting up an airborne relay, consisting of one or several flying wireless mesh nodes. The developed software includes basic functionality to control the UAVs and to setup, deploy, manage, and monitor a wireless mesh network. Our evaluations have shown that UAVNet can significantly improve network performance.