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Aerodynamic Analysis with Athena Vortex Lattice (AVL)Budziak, Kinga January 2015 (has links) (PDF)
This project evaluates the suitability and practicality of the program Athena Vortex Lattice (AVL) by Mark Drela.
A short user guide was written to make it easier (especially for students) to get started with the program AVL.
AVL was applied to calculate the induced drag and the Oswald factor.
In a first task, AVL was used to calculate simple wings of different aspect ratio A and taper ratio lambda.
The Oswald factor was calculated as a function f(lambda) in the same way as shown by HOERNER.
Compared to HOERNER's function, the error never exceed 7.5%.
Surprisingly, the function f(lambda) was not independent of aspect ratio, as could be assumed from HOERNER.
Variations of f(lambda) with aspect ratio were studied and general results found.
In a second task, the box wing was investigated. Box wings of different h/b ratio: 0.31, 0.62, and 0.93 were calculated in AVL.
The induced drag and Oswald factor in all these cases was calculated.
An equation, generally used in the literature, describes the box wing's Oswald factor with parameters k1, k2, k3 and k4.
These parameters were found from results obtained with AVL by means of the Excel Solver.
In this way the curve k = f(h/b) was plotted.
The curve was compared with curves with various theories and experiments conducted prior by other students.
The curve built based on AVL fits very well with the curve from HOERNER, PRANDTL and a second experiment made in the wind tunnel at HAW Hamburg.
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Modeling diesel combustion in heavy duty engine using detailed chemistry approach and CFDDuyar, Serkan January 2014 (has links)
Emission and fuel consumption are among the key parameters when designing a combustion system. Combustion CFD can assist in this task only if good enough accuracy is achieved regarding combustion and emission predictions. The aim of this master thesis is to evaluate the use of detailed reaction mechanisms (as a substitute for standard combustion model) in terms of computational time and result accuracy. Several mechanisms for n-heptane are tested. Lund University optical engine experimental case is used for this evaluation.Results showed that detailed chemistry can predict ignition accurately but differences are observed in the peak cylinder pressure. The computational time also increased significantly as size and complexity of the mechanism increased. Recommendations are given to improve predictions using detailed chemistry approach which is found to be an interesting approach especially for lift-off length predictions.
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CFD Simulation of Urea Evaporation in STAR-CCM+Ottosson, Oscar January 2019 (has links)
Diesel engines produce large amounts of nitrogen oxides (NOX) while running. Nitrogen oxides are highly toxic and also contribute towards the formation of tropospheric ozone. Increasingly stringent legislation regarding the amount of nitrogen oxides that are allowed to be emitted from diesel-powered vehicles has forced manufacturers of diesel-engines to develop after-treatment systems that reduce the amount of nitrogen oxides in the exhaust. One of the main components in such a system is selective catalytic reduction (SCR), where nitrogen oxides are reduced to diatomic nitrogen and water with the help of ammonia. A vital part of this process is the spraying of a urea-water-solution (UWS), which is needed in order to produce the reducing agent ammonia. UWS spraying introduces the risk of solid deposits (such as biuret, ammelide and ammeline) forming in the after-treatment system, should the flow conditions be unfavourable. Risk factors include high temperatures, but also low dynamics and high thickness of the resulting liquid film that forms as the UWS spray hits the surfaces of the after-treatment system. It is thus essential that manufacturers of SCR after-treatment systems have correct data on how much UWS that should be sprayed into the exhaust for any given flow condition. Experimental tests are thoroughly used to assess this but are very expensive and are thus limited to prototype testing during product development. When assessing a wider range of concepts and geometries early on in the product development stage, simulation tools such as computational fluid dynamics (CFD) are used instead. One of the most computationally heavy processes to simulate within a SCR after-treatment system is the UWS spray and its interaction with surfaces inside the after-treatment system, where correct prediction of the formation of solid deposits are of great importance. Most CFD models used for this purpose hold a relatively good level of accuracy and are utilized throughout the whole industry where SCR aftertreatment is applied. Despite this, these models are limited in the fact that they are only able to cover timescales in the scope of seconds to minutes while using a tolerable amount of computational power. However, the time spectrum for solid deposit formation is minutes to hours. Scania is one of Sweden’s biggest developers of SCR after-treatment, with the technology being incorporated directly into its silencers. AVL Fire is the main UWS spray simulation tool for engineers at Scania at the moment. One major drawback of using AVL Fire for UWS spray simulations is that it is deemed too time-consuming to set up new cases and too unstable during simulation, which makes it too costly in terms of expensive engineering hours. This project has investigated the potential of using STAR-CCM+ for UWS spray simulations at Scania instead. A standard method has been evaluated, as well as parameters that will prove useful in further investigations of a potential speedup method. The studied method in STAR-CCM+ is easy to setup and the simulation process is robust and stable. Various other perks come from using STAR-CCM+ as well, such as: a user-friendly interface, easy and powerful mesh-generation and great post-process capabilities. Several different parameters have been investigated for their impact on the studied method, such as mesh refinement of the spray injector area and the number of parcels injected every time-step through the spray injector (simply put the resolution of the spray). A possible speedup by freezing the momentum equations when allowed and lowering the amount of inner iterations has also been investigated. A handful of operating conditions have been studied for two different geometries. The attained simulation results display correlations with physical measurements, but further assessment for identifying the risk of solid deposit needs to be performed on the studied cases to assess the full accuracy of solid deposit prediction of the studied method. Recommendations for future work includes fully implementing and evaluating the speedup method available for spray simulations in STAR-CCM+ as well as directly comparing how the accuracy and performance of the method relates to that of the method used in AVL Fire for spray simulations. / Dieselmotorer producerar under körning stora mängder kväveoxider (NOx). Kväve-oxider är starkt giftiga föreningar som även bidrar till att öka mängden marknära ozon. Allt strängare lagstiftning gällande mängden kväveoxider som får släppas ut från fordon med dieselmotorer har lett till att tillverkare av dieselmotorer blivit tvingade att utveckla efterbehandlingssystem som renar avgasen från motorn. En av huvudkomponenterna i ett sådant system idag är selective catalytic reduction (SCR; på svenska selektiv katalytisk reduktion), där kväveoxider omvandlas till kvävgas och vatten med hjälp av ammoniak. För att producera ammoniak används en lösning av urea och vatten (t.ex. AdBlue®), som introduceras till efterbehandlingssystemet via spray. Denna process har dock en stor nackdel, då det under omvandlingsprocessen kan finnas risk för klumpbildning av ämnen som biuret, ammelid och ammelin ifall flödesförhållandena är ogynnsamma. Riskfaktorer för klumpbildning inkluderar höga temperaturer samt låg dynamik och hög tjocklek för den vätskefilm som bildas när sprayen med urea-lösning kommer i kontakt med ytor i efterbehandlingssystemet. Det är därför av stor vikt för tillverkare av efterbehandlingssystem som använder SCR att känna till hur mycket urealösning som kan sprayas in för varje givet flöde. Experimentella tester används till stor del för att utvärdera detta, men är väldigt dyra och kan endast göras för ett fåtal prototyper under en produkts utveckling. För att kunna utvärdera ett större antal koncept och geometrier tidigare i utvecklingsstadiet av en ny produkt används därför ofta datorkraft med simuleringsverktyg som CFD (Computational Fluid Dynamics). En av de mest beräkningstunga processerna att simulera i ett efterbehandlingssystem med SCR är sprayandet av urea-lösning och dess interaktion med ytor, där korrekta förutbestämmelser av huruvida det finns risk för klumpbildning eller inte är av stor betydelse. De flesta CFD modeller som används i detta syfte har förhållandevis god noggrannhet och används i stor utsträckning i den bransch där efterbehandling med SCR tillämpas. Däremot är dessa modeller begränsade i att de endast kan åstadkomma simuleringar (med en acceptabel mängd datorkraft) som sträcker sig i tidsintervallet sekunder till minuter. Bildningen av klump är dock en process som kan ta upp till flera timmar. Scania är en av Sveriges största tillämpare av SCR, då tekniken används i de efterbehandlingssystem som finns inbyggda i tillverkarens ljuddämpare. Scania använder främst AVL Fire för simulering av spray med urea. AVL Fire anses dock vara för tidskrävande vid skapelsen av nya simuleringsfall och för instabilt under simulering. Detta projekt har därför undersökt möjligheten att använda STAR-CCM+ för simulering av spray med urea hos Scania. Den metod i STAR-CCM+ som utvärderats är enkel att använda då nya simuleringsfall ska skapas, samtidigt som den är robust och stabil under simulering. Relevanta parametrar för en potentiell uppsnabbningsmetod har också undersökts. STAR-CCM+ i sin helhet är användarvänligt, där verktyget för att skapa och generera mesh är enkelt att använda såväl som kraftfullt när mer avancerade operationer krävs. Möjligheterna för postprocessing är väldigt smidiga för transienta förlopp, vilket är ett stort plus för simuleringar med urea-spray, vars injektion och resulterande processer är väldigt transienta skeenden i sig. Flera olika parametrar har undersökts, för att granska hur stor påverkan de har på prestandan och noggrannheten hos den studerade metoden. Två av dessa är tätheten av beräkningsnoder i den region där spray-munstycket är placerat samt antalet paket med urea-vatten lösning som injiceras varje tidssteg via spray-munstycket. En möjlig uppsnabbning av metoden, som går ut på att frysa ekvationerna för bevarelse av rörelsemängd (eng - momentum equations) när det är tillåtet och samtidigt minska antalet inre iterationer för varje tidssteg, har också undersökts. Ett flertal olika flödesförhållanden har också undersökts för två olika geometrier. De erhållna resultaten tyder på korrelation med data från fysiska experiment. Dock bör ytterligare hydrodynamiska utvärderingar tillämpas för att ordentligt kunna redogöra för hur väl STAR-CCM+ kan användas för att förutse risken för klump- bildning i en spray-process med urea-vatten lösning. Framtida arbete borde fokusera på att utvärdera den uppsnabbningsmetod som finns för spray-simuleringar i STAR-CCM+, samt direkt jämföra hur väl metodens noggrannhet och prestanda står sig gentemot den metod som används i AVL Fire för spray-simuleringar.
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Previsão de localização futura de veículos baseada em dados de AVL. / Future location prediction of vehicles based on data AVL.Barbosa, Luciano Aparecido 04 October 2010 (has links)
O crescente desenvolvimento de aplicações utilizadas por dispositivos móveis que fazem uso das tecnologias de posicionamento via satélite e comunicação móvel, juntamente com a popularização destes dispositivos, sejam eles celulares ou GPSs (Global Positioning System) automotivos reforçam ainda mais a necessidade de representação e o entendimento a cerca das entidades móveis retratadas nestes dispositivos e incentivam estudos que forneçam um significado maior do que a simples representação posicional destas entidades. Considera-se neste trabalho, que estas entidades móveis são veículos rastreados via satélite que fornecem sua posição espacial, determinada por um par de coordenadas geográficas (latitude e longitude), coletadas em intervalos de tempo regulares para sistemas AVL (Automatic Vehicle Location) que são responsáveis pelo monitoramento do estado destes veículos. Neste trabalho, foram desenvolvidas funções para a previsão da localização e geração de padrões dos veículos monitorados por sistemas AVL. Para tanto, as paradas efetuadas pelos veículos irão definir regiões comuns de parada ocorridas durante um intervalo de tempo passado e serão consideradas como um padrão de localização, enquanto que as trajetórias serão utilizadas para definir o padrão de movimentação. Os relacionamentos topológicos que estes padrões possuem irão definir por meio de condições espaciais/direcionais e temporais quais serão as regiões de paradas consideradas como prováveis destinos, a partir de outra região de parada, considerada como origem e, permitirão a geração de matrizes com valores de frequências relativas que consideram o número de visitas que uma região recebe a partir da outra. O que possibilita extrair valores de probabilidade condicional para cada destino provável. Portanto, a metodologia proposta e as funções desenvolvidas que foram validadas em experimentos, que utilizaram dados reais de rastreamento, fornecem uma camada inicial de inteligência aos sistemas AVL, que proporciona aos controladores destes sistemas utilizarem consultas preditivas, identificarem mais facilmente anomalias de comportamento, que possam evidenciar alguma ocorrência incomum na movimentação do veículo, além de aumentar a segurança dos veículos que possuem um dispositivo de rastreamento por meio da definição de padrões inerentes ao veículo. / The increasing development of applications used by mobile devices that make use of the technologies of satellite positioning and mobile communications, along with the popularity of these devices, whether cell phones or GPS\'s (Global Positioning System) automotive further reinforce the need for representation and understanding about the mobile entities represent in these devices and encourage studies that provide a greater meaning than the simple positional representation of these entities. It is considered in this work that these entities are tracked vehicles that provide satellite spatial position, determined by a pair of coordinates (latitude and longitude), collected at regular time intervals for systems AVL (Automatic Vehicle Location) that are responsible for monitoring the state of these vehicles. In this work, functions have been developed to predict the location and pattern generation of vehicles monitored by AVL systems. Accordingly, these stops will define common regions of the stop occurred during a period of time past and will be considered as the pattern location, while the trajectories are used to define the pattern of movement of the vehicle. The topological relationships that have these patterns define conditions through spatial/directional and temporal, which are stops regions considered as probable destinations from another stop region, regarded as origin and allow the generation of matrices with values of frequencies on considering the number of visits that region receives from the other. What makes it possible to extract values of conditional probability for each likely destination. Therefore, the proposed methodology and functions developed that been validated in experiments using real data to tracking provide a initial layer of intelligence to the AVL system that gives drivers of these systems use predictive queries, more easily identify behavioral abnormalities that may show some unusual occurrence in moving the vehicle, in addition to increasing the safety of vehicles which have a tracking device by setting patterns relating to the vehicle.
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Metodologia de geração dinâmica de padrões de viagens rodoviárias para monitoramentos inteligentes de veículos de carga em sistemas AVL. / Dynamic generation metodology of road travel patterns to vehicles intelligent monitoring in AVL systems.Cunha, Joana Nicolini 18 September 2008 (has links)
A presente dissertação traz a questão da aderência de viagens de veículos em monitoramentos inteligentes com sistemas Automatic Vehicle Location (AVL) que operam em rotas rodoviárias. Uma viagem é considerada como uma série de \"passadas\", que correspondem ao tempo em que o veículo está em movimento, mas excluindo os tempos gastos em paradas para atividades como carregamento/descarregamento entre outras. A partir de dados históricos coletados via Global Positioning System (GPS) pelo sistema AVL, uma metodologia de filtragem e aplicações estatísticas para geração das passadas é apresentada. Além disso, são propostos métodos para geração de padrões de viagem de referência, baseados em tempos de viagem e velocidades, desvios padrões, locais de descontinuidades entre outros parâmetros. A geração desses padrões em conjunto com procedimentos operacionais permite o monitoramento eficiente do progresso de viagens de frotas de veículos, para finalidades logísticas e de segurança. O progresso de um veículo ao longo de uma rota é analisado diante dos padrões de viagem de referência obtidos a partir de suas viagens prévias, de veículos similares na mesma rota ou de viagens em rotas de mesma classe, dependendo do que for mais adequado. A geração de padrões é um processo dinâmico que gera conhecimento sobre o veículo e comportamento da rodovia ao longo do tempo. Desenho do processo de monitoramento do progresso de viagem é apresentado, no qual, a cada nova coleta de dado GPS ou a cada instante solicitado pelo usuário, a aderência é medida, eventuais descontinuidades (saídas da rota, paradas ou mudança de sentido) são identificadas e avisos são gerados. Tal aderência é definida por índice de desempenho que considera os desvios de tempo em relação a valores de referência e respectivas tolerâncias. Para experimentação da metodologia, foi realizada simulação de viagem na rodovia BR116 na ligação São Paulo - Rio de Janeiro, sobre base com cerca de 130.000 registros de dados GPS associados. Com integração em Geographic Information System (GIS) para suporte de funcionalidades, foram gerados os padrões de viagem e simulado o processo de monitoramento com sucesso. / This dissertation addresses the question of vehicle travel adherence in intelligent monitoring with Automatic Transportation Location (AVL) operating in a regional environment. A trip is considered as series of runs, corresponding to time in movement but excluding time spent on activities such as loading/unloading and others. Based on historic data collected from AVL/GPS a statistical data filtering method to generate the runs is presented. Furthermore, statistical methods are proposed to generate travel patterns based on travel time, speed, standard deviation and other parameters. The pattern generation together with operational procedures allows effective monitoring of large fleets in logistics and safety. The progress of a vehicle along a route is evaluated face to the statistical patterns of its previous successful trips or against statistical patterns of similar vehicles on the same route, whichever appropriate. The generation of patterns is a dynamic continuous process that generates knowledge on vehicle and road behavior along time. A broad outline of the travel monitoring process is presented. Whenever the requested by user, the process calculates the travel adherence, identifies abnormalities and generates alarms. That adherence is defined by a performance index, which considers the travel time deviations from the reference values and the respective tolerances. Successful experimentation was carried out on the Rio de Janeiro - São Paulo motorway, with 130.000 Global Positioning System (GPS) positional data relayed from trucks to a Geographic Information System (GIS) based monitoring system in Brazil.
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Modelagem e simulação de grupo gerador diesel consumindo óleo vegetal “in natura” enriquecido com hidrogênio e oxigênio visando melhorar sua eficiência energéticaCAMPOS, Ricardo Augusto Seawright de 28 August 2015 (has links)
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Previous issue date: 2015-08-28 / Grupo gerador é um equipamento composto por um motor de combustão interna e um alternador, responsável pela geração de energia elétrica no mundo inteiro e também em muitas comunidades isoladas na região amazônica. O uso de combustíveis de origem fóssil em grupos geradores é bastante comum, havendo uma grande dependência mundial, desse tipo de combustível. Diante de um cenário mundial com possibilidades de escassez de petróleo e água, e apesar da matriz energética diversificada, o Brasil tem forte dependência dessas duas fontes de energia para geração de eletricidade. As pesquisas envolvendo a utilização de óleo vegetal “in natura” para substituir, parcial ou totalmente, os combustíveis fósseis, ou ser misturado a outros tipos de combustível vêm crescendo. Neste trabalho, foi realizada uma modelagem e simulação computacional de um grupo gerador consumindo óleo vegetal “in natura”, enriquecido com hidrogênio e oxigênio com o objetivo de melhorar sua eficiência energética, a partir de melhorias propostas na combustão. A modelagem e simulações foram realizadas com o software AVL BOOST®. O modelo computacional foi ajustado e validado junto a experimento realizado em um motor quatro tempos Diesel, injeção indireta, naturalmente aspirado, de 20 kW. O trabalho foi desenvolvido em duas fases. Na primeira, foi feita a substituição energética de óleo vegetal por hidrogênio, em parcelas de 0% a 20%, com intervalos de 5%. Na segunda, oxigênio, em base mássica, foi adicionado ao ar de admissão, em proporções pré-definidas, e o modelo foi simulado até que fosse atingido o limite operacional do motor. Foi considerado nas simulações, o grupo gerador operando com cargas de 75%, 80% e 100%. Nas duas etapas da investigação, os resultados indicaram um aumento na potência elétrica, diminuição do consumo específico de combustível e melhoria no rendimento global do grupo gerador. A utilização de H2 indicou aumento das emissões à plena carga. Na simulação realizada com O2, a formação de CO apresentou queda e Nox aumentou para cargas parciais. As simulações indicaram que a utilização desses dois vetores energéticos mostrou-se bastante promissora, melhorando a combustão do óleo vegetal “in natura“ e a eficiência energética do grupo gerador. / Generator set is a device formed by an internal combustion engine and an alternator responsible for electricity generation all over the world and in many isolated communities in the Amazon region. The use of fossil fuels in generators is very common with a great global dependency on this type of fuel. Facing a world stage with possibility of shortages of oil and water and despite the diversified energy matrix, Brazil has strong dependence of these two energy sources for electricity generation. Researches involving the use of vegetable oil "in natura" to replace, partially or completely, fossil fuels, or be mixed with other types of fuel are growing. In this paper, a modeling and computer simulation of a genset consuming vegetable oil "in natura" enriched with hydrogen and oxygen was carried out in order to improve their energy efficiency as from proposed improvements in the combustion. The modeling and simulations were performed with AVL Boost® software. The computational model was adjusted and validated with the experiment carried out in a Diesel engine of 20 kW, four strokes, indirect injection, naturally aspirated. The study was developed in two phases. At first, the energy substitution of vegetable oil by hydrogen was made in portions of 0% to 20%, in 5% intervals. In the second, oxygen in weight basis was added to the intake air in predefined proportions and the model was simulated until the engine operating limit was reached. It was considered the genset operating with loads of 75%, 80% and 100%, in the simulations. In the two stages of the investigation, the results indicated an increase in electrical power, reduced specific fuel consumption and improved overall efficiency of the generator set. The use of H2 showed increased emissions at full load. In the simulation performed with O2, CO formation decreased and NOx formation increased to partial loads. The simulations indicated that the use of these two energy carriers proved to be very promising, improving the combustion of vegetable oil "in natura" and the energy efficiency of the generator set.
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Linear Acoustic Modelling and Testing of Exhaust MufflersRamanathan, Sathish Kumar January 2007 (has links)
<p>Intake and Exhaust system noise makes a huge contribution to the interior and exterior noise of automobiles. There are a number of linear acoustic tools developed by institutions and industries to predict the acoustic properties of intake and exhaust systems. The present project discusses and validates, through measurements, the proper modelling of these systems using BOOST-SID and discusses the ideas to properly convert a geometrical model of an exhaust muffler to an acoustic model. The various elements and their properties are also discussed.</p><p>When it comes to Acoustic properties there are several parameters that describe the performance of a muffler, the Transmission Loss (TL) can be useful to check the validity of a mathematical model but when we want to predict the actual acoustic behavior of a component after it is installed in a system and subjected to operating conditions then we have to determine other properties like Attenuation, Insertion loss etc,.</p><p>Zero flow and Mean flow (M=0.12) measurements of these properties were carried out for mufflers ranging from simple expansion chambers to complex geometry using two approaches 1) Two Load technique 2) Two Source location technique. For both these cases, the measured transmission losses were compared to those obtained from BOOST-SID models.</p><p>The measured acoustic properties compared well with the simulated model for almost all the cases.</p>
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A real-time bus dispatching policy to minimize headway varianceBerrebi, Simon Jonas Youna 22 May 2014 (has links)
Transit agencies include buffer time in their schedules to maintain stable headways and avoid bus bunching. In this work, a real-time holding mechanism is proposed to dispatch buses on a loop-shaped route, solely based on operating conditions in real-time. Holds are applied at the terminal station to minimize the expected variance of bus headways at departure. The bus-dispatching problem is formulated as a stochastic decision process. The optimality equations are derived and structural properties of the optimal policy are inferred by backward induction. The exact optimal holding policy is then found in closed form, as a function of the expected travel time of buses currently running. A simulation assuming stochastic operating conditions and unstable headway dynamics is performed to assess the expected average waiting time of passengers at stations. The proposed control strategy is found to provide lower passenger waiting time and better resiliency than methods recommended in the literature and used in practice.
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Metodologia de geração dinâmica de padrões de viagens rodoviárias para monitoramentos inteligentes de veículos de carga em sistemas AVL. / Dynamic generation metodology of road travel patterns to vehicles intelligent monitoring in AVL systems.Joana Nicolini Cunha 18 September 2008 (has links)
A presente dissertação traz a questão da aderência de viagens de veículos em monitoramentos inteligentes com sistemas Automatic Vehicle Location (AVL) que operam em rotas rodoviárias. Uma viagem é considerada como uma série de \"passadas\", que correspondem ao tempo em que o veículo está em movimento, mas excluindo os tempos gastos em paradas para atividades como carregamento/descarregamento entre outras. A partir de dados históricos coletados via Global Positioning System (GPS) pelo sistema AVL, uma metodologia de filtragem e aplicações estatísticas para geração das passadas é apresentada. Além disso, são propostos métodos para geração de padrões de viagem de referência, baseados em tempos de viagem e velocidades, desvios padrões, locais de descontinuidades entre outros parâmetros. A geração desses padrões em conjunto com procedimentos operacionais permite o monitoramento eficiente do progresso de viagens de frotas de veículos, para finalidades logísticas e de segurança. O progresso de um veículo ao longo de uma rota é analisado diante dos padrões de viagem de referência obtidos a partir de suas viagens prévias, de veículos similares na mesma rota ou de viagens em rotas de mesma classe, dependendo do que for mais adequado. A geração de padrões é um processo dinâmico que gera conhecimento sobre o veículo e comportamento da rodovia ao longo do tempo. Desenho do processo de monitoramento do progresso de viagem é apresentado, no qual, a cada nova coleta de dado GPS ou a cada instante solicitado pelo usuário, a aderência é medida, eventuais descontinuidades (saídas da rota, paradas ou mudança de sentido) são identificadas e avisos são gerados. Tal aderência é definida por índice de desempenho que considera os desvios de tempo em relação a valores de referência e respectivas tolerâncias. Para experimentação da metodologia, foi realizada simulação de viagem na rodovia BR116 na ligação São Paulo - Rio de Janeiro, sobre base com cerca de 130.000 registros de dados GPS associados. Com integração em Geographic Information System (GIS) para suporte de funcionalidades, foram gerados os padrões de viagem e simulado o processo de monitoramento com sucesso. / This dissertation addresses the question of vehicle travel adherence in intelligent monitoring with Automatic Transportation Location (AVL) operating in a regional environment. A trip is considered as series of runs, corresponding to time in movement but excluding time spent on activities such as loading/unloading and others. Based on historic data collected from AVL/GPS a statistical data filtering method to generate the runs is presented. Furthermore, statistical methods are proposed to generate travel patterns based on travel time, speed, standard deviation and other parameters. The pattern generation together with operational procedures allows effective monitoring of large fleets in logistics and safety. The progress of a vehicle along a route is evaluated face to the statistical patterns of its previous successful trips or against statistical patterns of similar vehicles on the same route, whichever appropriate. The generation of patterns is a dynamic continuous process that generates knowledge on vehicle and road behavior along time. A broad outline of the travel monitoring process is presented. Whenever the requested by user, the process calculates the travel adherence, identifies abnormalities and generates alarms. That adherence is defined by a performance index, which considers the travel time deviations from the reference values and the respective tolerances. Successful experimentation was carried out on the Rio de Janeiro - São Paulo motorway, with 130.000 Global Positioning System (GPS) positional data relayed from trucks to a Geographic Information System (GIS) based monitoring system in Brazil.
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Previsão de localização futura de veículos baseada em dados de AVL. / Future location prediction of vehicles based on data AVL.Luciano Aparecido Barbosa 04 October 2010 (has links)
O crescente desenvolvimento de aplicações utilizadas por dispositivos móveis que fazem uso das tecnologias de posicionamento via satélite e comunicação móvel, juntamente com a popularização destes dispositivos, sejam eles celulares ou GPSs (Global Positioning System) automotivos reforçam ainda mais a necessidade de representação e o entendimento a cerca das entidades móveis retratadas nestes dispositivos e incentivam estudos que forneçam um significado maior do que a simples representação posicional destas entidades. Considera-se neste trabalho, que estas entidades móveis são veículos rastreados via satélite que fornecem sua posição espacial, determinada por um par de coordenadas geográficas (latitude e longitude), coletadas em intervalos de tempo regulares para sistemas AVL (Automatic Vehicle Location) que são responsáveis pelo monitoramento do estado destes veículos. Neste trabalho, foram desenvolvidas funções para a previsão da localização e geração de padrões dos veículos monitorados por sistemas AVL. Para tanto, as paradas efetuadas pelos veículos irão definir regiões comuns de parada ocorridas durante um intervalo de tempo passado e serão consideradas como um padrão de localização, enquanto que as trajetórias serão utilizadas para definir o padrão de movimentação. Os relacionamentos topológicos que estes padrões possuem irão definir por meio de condições espaciais/direcionais e temporais quais serão as regiões de paradas consideradas como prováveis destinos, a partir de outra região de parada, considerada como origem e, permitirão a geração de matrizes com valores de frequências relativas que consideram o número de visitas que uma região recebe a partir da outra. O que possibilita extrair valores de probabilidade condicional para cada destino provável. Portanto, a metodologia proposta e as funções desenvolvidas que foram validadas em experimentos, que utilizaram dados reais de rastreamento, fornecem uma camada inicial de inteligência aos sistemas AVL, que proporciona aos controladores destes sistemas utilizarem consultas preditivas, identificarem mais facilmente anomalias de comportamento, que possam evidenciar alguma ocorrência incomum na movimentação do veículo, além de aumentar a segurança dos veículos que possuem um dispositivo de rastreamento por meio da definição de padrões inerentes ao veículo. / The increasing development of applications used by mobile devices that make use of the technologies of satellite positioning and mobile communications, along with the popularity of these devices, whether cell phones or GPS\'s (Global Positioning System) automotive further reinforce the need for representation and understanding about the mobile entities represent in these devices and encourage studies that provide a greater meaning than the simple positional representation of these entities. It is considered in this work that these entities are tracked vehicles that provide satellite spatial position, determined by a pair of coordinates (latitude and longitude), collected at regular time intervals for systems AVL (Automatic Vehicle Location) that are responsible for monitoring the state of these vehicles. In this work, functions have been developed to predict the location and pattern generation of vehicles monitored by AVL systems. Accordingly, these stops will define common regions of the stop occurred during a period of time past and will be considered as the pattern location, while the trajectories are used to define the pattern of movement of the vehicle. The topological relationships that have these patterns define conditions through spatial/directional and temporal, which are stops regions considered as probable destinations from another stop region, regarded as origin and allow the generation of matrices with values of frequencies on considering the number of visits that region receives from the other. What makes it possible to extract values of conditional probability for each likely destination. Therefore, the proposed methodology and functions developed that been validated in experiments using real data to tracking provide a initial layer of intelligence to the AVL system that gives drivers of these systems use predictive queries, more easily identify behavioral abnormalities that may show some unusual occurrence in moving the vehicle, in addition to increasing the safety of vehicles which have a tracking device by setting patterns relating to the vehicle.
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