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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Reliable Real-Time Communication for Future ITS (Intelligent Transport Systems) using HWA (Heterogeneous Wireless Access)

AFGHANI, AHMAD January 2011 (has links)
In this research oriented master’s thesis we have proposed a future vision of ITS (Intelligent Transport Systems) by utilizing the novel concept of HWA (Heterogeneous Wireless Access). Our proposal is backed by the investigation of the results of experiments conducted at CERES (Centre for Research on Embedded Systems), Halmstad University, Sweden to evaluate the quality of communication for V2V and V2I by using the IEEE 802.11p standard. We have also identified the expected scenarios with need of any other communication technology in replacement of IEEE 802.11p for V2V and V2I communication. We have also investigated the relevant research projects, experiments and their results on the basis of predefined constraints. In the investigated research projects the concept of HWA has been correlated with our proposal of HWA for ITS. We have identified that for smooth integration of any communication technology with IEEE 802.11p, an efficient and smart vertical handover protocol or method will be required. We have presented a blue print of a custom designed vertical handover technique which can be implemented for future ITS with further enhancements and experimental evaluations. We have also evaluated the worst case scenarios to assess the suitability of the HWA for the ITS. We proposed few solutions based on the evaluation of communication scenarios for the integration of IEEE 802.11p with other wireless communication technologies. Finally we have provided some conclusions and suggested future researches which must be conducted to realize the dream of ITS with support of HWA.
42

Modelo de gestão por processo de negócios para automação de centros integrados de mobilidade urbana. / Management model for business process automation of integrated centers urban mobility.

José Evaldo Gonçalo 08 December 2016 (has links)
Mobilidade Urbana é uma das questões mais importantes da atualidade, pois afeta uma parcela significativa da população, impacta fortemente a poluição ambiental, é um problema mundial e tende a piorar com o aumento da densidade populacional e das cidades. A provisão de grandes obras de infraestrutura é cada vez mais difícil e onerosa, sendo necessário o uso da tecnologia e da integração de sistemas para o melhor aproveitamento da estrutura existente. O objetivo desta tese é propor um modelo de gestão para automação de centros integrados aderentes às realidades de custo, disponibilidade tecnológica, cultura organizacional e estratégias políticas de cidades com características semelhantes aos grandes e médios municípios do Brasil. Tal modelo permite, dentre outras contribuições, promover melhorias nas tomadas de decisão por gestores da área de mobilidade urbana por meio da incorporação e da liberação de dados e informações dentro de uma modelagem de gestão que visa facilitar as parcerias e a comunicação entre diferentes setores. As maiores cidades brasileiras estão buscando se atualizar para resolver seus problemas de mobilidade e passam por um período de transformação. A proposta do Centro Integrado de Mobilidade Urbana possibilita automatizar processos, implementar novas funcionalidades, fornecer informações para usuários, compartilhar recursos e diminuir custos. A utilização de ferramentas do arcabouço da Modelagem por Processos de Negócios (BPM) é a escolha lógica para um sistema que lida com tantas interrupções. Ao se projetar modelos de trabalho com o intuito de incorporar novas tecnologias e/ou torná-los mais eficientes, é preciso modelá-los de alguma maneira. O sistema de BPM adapta-se bem à necessidade de padronização e reprodutibilidade de processos, propiciando ainda a agregação de múltiplas saídas por processo. A visibilidade e o alcance desta metodologia aumenta a sobrevida de modelagens realizadas nesta base. O desenvolvimento de aplicativos de mobilidade deve acontecer de forma acelerada nos próximos anos. Como demonstrado, a necessidade de automação, integração e consolidação de informações corroboram com a de criação de um Centro Integrado. A utilização dos sistemas propostos é uma maneira de formalizar e aumentar a busca por parcerias e facilitar colaborações tanto no sentido de captar quanto de informar, dando suporte às pesquisas internas de órgãos públicos e privados. / Urban Mobility is one of the most important issues of our times, because it affects a significant portion of the population, strongly impacts the environmental pollution, it is a global problem and tends to get worse with increasing of population density and cities. The delivery of major infrastructure is becoming increasingly difficult and costly, requiring the use of technology and systems integration for better utilization of the existing structure. The objective of this thesis is to propose a management model for automation of integrated centers connected to cost realities, technological availability, organizational culture and political strategies of cities similar to large and mediumsized municipalities in Brazil. This model allows, among other contributions, to promote improvements in the decision making process by managers of urban mobility area through the incorporation and release of data and information within a management model to facilitate partnerships and communication among different sectors. The largest Brazilian cities are seeking to update themselves to solve their mobility problems and undergo a period of transformation. The Integrated Urban Mobility Center proposed allow to automate processes, implement new functionalities, provide information to users, share resources and reduce costs. Using tools from the Business Process Modeling (BPM) framework is the logical choice for a system that handles so many disruptions. When designing work model to incorporate new technologies and / or to make them more efficient, it is necessary to modeled it in some way. The BPM system adapts well to the needs of standardization and processes reproducibility, further enabling aggregation of multiple outputs by process. The visibility and extent of this methodology increases the life time of modeling performed on this basis. The development of mobility apps will happen rapidly in the coming years. As demonstrated, the need for automation, integration and consolidation of information corroborates with the creation of an Integrated Center. The use of the proposed systems is a way to formalize and increase the search for partnerships and facilitate collaboration both to capture as to inform, supporting the internal researches of private and public agencies.
43

Roles of factors in simulation of parking guidance and information systems

Peng, Wendi, Surveying & Spatial Information Systems, Faculty of Engineering, UNSW January 2008 (has links)
The Parking Guidance and Information (PGI) system is an important application of Intelligent Transport System (ITS), which has been shown to be an effect service for traffic information and parking management. The roadside Variable Message Sign (VMS) board has been the usual media for the publication of parking information in early PGI systems, and its performance over the years has been studied via simulations and questionnaire surveys. However, survey results show significant discrepancies across various traffic networks in different areas. More recently, parking information services have become available on other media such as mobile and in-vehicle devices. In contrast to VMS-based systems, PGI systems based on new media, especially the in-vehicle class of devices, have not been studied separately. This thesis aims to conduct research into the performance of PGI systems based on invehicle devices, by simulating and comparing a VMS-based PGI system with a Vehicle On-Board Device (VOBD)-based PGI system. A specially designed simulator utilising a routing algorithm known as the Ad hoc On-Demand Distance Vector (AODV) routing protocol in computer networks, has been created in MATLAB. The simulation minimises the influence of specific structures of traffic networks that may be found in some networks, but not others. This is done by simulating a grid-based road network where the capacities of parking stations and their geographic distribution are randomly allocated within specific zones, and the parking demand in each run of simulations is variable load. The results of simulations, including the information reliability, reduction of travel time, demand on on-street parking and the utilisation rates of parking stations, are analysed for multiple scenarios where the compliance rate, the information update policy and the strategy of human behaviour are varied. The analyses reveal a significant advantage of VOBD-based PGI systems over VMS-based PGI systems in terms of the quality of information and the reduction of travel time. At the same time, the analyses highlight the limitations of a PGI system when the demand and supply of parking stations is not appropriately balanced.
44

Adaptive brake lights : an investigation into their relative benefits in regards to road safety

Roughan, Craig January 2007 (has links)
The implementation of In-Vehicle Intelligent Transport Systems (ITS) is becoming a common occurrence in modern vehicles. Automobile manufacturers are releasing vehicles with many forms of sophisticated technologies that remove much of the responsibility of controlling an automobile from the driver. These In-Vehicle Intelligent Transport Systems have stemmed from a genuine need in regards to road safety, however there are advantages and disadvantages associated with ITS. Each different form of technology has its own inherent compromises in relation to road safety, driver behaviour and driver comfort. This thesis outlines the benefits and detrimental effects associated with current In-Vehicle Intelligent Transport Systems and details the development and user interface testing of an adaptive brake light. The adaptive brakelight concept aims to provide drivers with the advantages of an In-Vehicle ITS whilst removing the disadvantages. The technology will help drivers judge the braking pattern of the car in front, thus allowing them to react appropriately and potentially reducing the occurrence of rear-end crashes. The adaptive brake light concept was tested in comparison to a standard brake light and BMW inspired brake light in a series of user interface tests. The adaptive brake light was shown overall to be an improved method of displaying the varying levels of deceleration of a lead vehicle. Whilst different age and gender groups responded differently to the adaptive brake light, it was shown to be of benefit to the majority and the most at risk groups responded positively to the adaptive brake light. This research shows that an adaptive brake light can provide a benefit in regards to road safety when compared to a standard brake light interface. It is hoped that further development of variable brake lights will result from this research and possibly lead to the implementation of the technology to automobiles and other forms of transport.
45

Roles of factors in simulation of parking guidance and information systems

Peng, Wendi, Surveying & Spatial Information Systems, Faculty of Engineering, UNSW January 2008 (has links)
The Parking Guidance and Information (PGI) system is an important application of Intelligent Transport System (ITS), which has been shown to be an effect service for traffic information and parking management. The roadside Variable Message Sign (VMS) board has been the usual media for the publication of parking information in early PGI systems, and its performance over the years has been studied via simulations and questionnaire surveys. However, survey results show significant discrepancies across various traffic networks in different areas. More recently, parking information services have become available on other media such as mobile and in-vehicle devices. In contrast to VMS-based systems, PGI systems based on new media, especially the in-vehicle class of devices, have not been studied separately. This thesis aims to conduct research into the performance of PGI systems based on invehicle devices, by simulating and comparing a VMS-based PGI system with a Vehicle On-Board Device (VOBD)-based PGI system. A specially designed simulator utilising a routing algorithm known as the Ad hoc On-Demand Distance Vector (AODV) routing protocol in computer networks, has been created in MATLAB. The simulation minimises the influence of specific structures of traffic networks that may be found in some networks, but not others. This is done by simulating a grid-based road network where the capacities of parking stations and their geographic distribution are randomly allocated within specific zones, and the parking demand in each run of simulations is variable load. The results of simulations, including the information reliability, reduction of travel time, demand on on-street parking and the utilisation rates of parking stations, are analysed for multiple scenarios where the compliance rate, the information update policy and the strategy of human behaviour are varied. The analyses reveal a significant advantage of VOBD-based PGI systems over VMS-based PGI systems in terms of the quality of information and the reduction of travel time. At the same time, the analyses highlight the limitations of a PGI system when the demand and supply of parking stations is not appropriately balanced.
46

A framework for the deployment of traffic safety technologies in Abu Dhabi highways

Al Junaibi, Musallem January 2016 (has links)
There has been a good effort made in Abu Dhabi for the last couple of years between government stakeholders to develop a road safety strategy, define rules and responsibilities, and gain a fully coordinated and integrated framework to deal with road safety. According to my point of view, the challenges that might be seen as a problem for the future development of Abu Dhabi can be the management and the usage of traffic safety technologies to reduce serious road traffic accidents. This study focused on the relationship between the use of traffic safety technologies and serious road traffic accidents on Abu Dhabi Highways. The motivation for this research is to implement correctly the traffic safety technologies in Abu Dhabi highways as a part of the need to adopt plans, programmes, and preventive measures to reduce or prevent the occurrence of traffic accidents in order to ensure the safety of individuals and property, in addition to preserving the security of the state and its human and economic components. The overall approach to this study is a mixed methodology, which combines quantitative and qualitative methods. A questionnaire is one method used in this regard, and is designed to be quantitative. In the quantitative method, comparing statistics of fatalities and injuries before and after installation of the speed cameras is used. As a result of this study and by making the connectivity between reviewing the results and findings of the literature review, identifying the questionnaire results, and exploring the before and after statistics led to findings which were used to develop a decision support framework that can be used to advise the regional safety strategy to be sustainable. The design framework was also validated through Abu Dhabi highways by a panel of experts, which was carried out using the focus group method, which was qualitative in nature. It is recommended from this research to invest much in traffic safety technologies, focus more on driver support systems and rapid response systems, improve driver behaviour as a priority in Abu Dhabi highways using traffic safety technologies, and integrate the compatibility of all of the above through an integrated system and specific performance indicators that are measured and followed up on an ongoing basis, and supported by geographic information systems (GIS).
47

RFID a sledování přepravy nebezpečného nákladu v silniční dopravě / RFID and Monitoring of Hazardous Goods in Road Transport

Fiala, Lukáš January 2012 (has links)
This Master's thesis examines the possibility of implementing an intelligent transport system for monitoring road vehicles carrying dangerous goods through the territory of the Czech Republic, for the purpose of providing relevant information to emergency responders in the event of an accident involving such vehicles. The aim is to explore whether, and how, can radio-frequency identification technology be used in such a system. The scope of the research is not limited to technical aspects of the solution. Various options are considered in terms of capital costs, complexity of the required information system and impact on shippers and carriers from an economic and business process standpoint. The paper briefly describes the current legislation concerning the transport of dangerous goods, the existing processes and entities involved in transport and handling of traffic accidents. Following is a comparison of several possible implementations of the monitoring system.
48

Emergency Braking in Compact Vehicle Platoons: A Cyber-Physical Design

Krishna Murthy, Dharshan 24 March 2021 (has links)
With the advent of autonomous driving, concepts like road trains or platoons are becoming more popular. In these arrangements, vehicles travel at separations of only 5 to 10m between them. These short inter-vehicle distances allow compacting vehicle flows resulting in increased throughput on highways. In addition, there are also fuel/energy savings as the magnitude of aerodynamic resistance acting on vehicles is reduced. These benefits increase when reducing inter-vehicle separations to below 5m. However, it becomes extremely difficult to guarantee safety, especially, when braking in an emergency. The longitudinal and lateral control systems developed so far aim to achieve string stability in the cruise scenario, i.e., to prevent that small variations at the lead magnify towards the trail. Unfortunately, this has no relevance during emergency braking, since control systems incur saturation, i.e., the condition where computed output brake forces exceed those that can be applied by actuators. This is because all vehicles have to apply their maximum brake forces in order to minimize the stopping distance of the platoon and reach a complete standstill. As a result, emergency braking requires special attention and needs to be designed and verified independent of the cruise scenario. Braking in an emergency is mainly characterized by the problem of heterogeneous deceleration capabilities of vehicles, e.g., due to their type and/or loading conditions. As a result, a deceleration rate possible by one vehicle may not be achievable by its immediately leading or following vehicles. Not addressing this heterogeneity leads to inter-vehicle collisions. Moreover, transitions in the road profile increase the complexity of such brake maneuvers. Particularly, when there is a transition from a flat road to a steep downhill, an already saturated brake controller cannot counteract the effect of the downhill slope. Hence, its deceleration magnitude will be reduced, potentially leading to intra-platoon crashes that would otherwise not occur on a flat road. In this work, we first analyze the problem of emergency braking in platoons operating at inter-vehicle separations below 5m and under idealized conditions (i.e., flat road, instantaneous deceleration, etc.). For this case, we propose a cyber-physical approach based on exploiting space buffers that are present in the separations between vehicles, and compare it with straightforward schemes (such as Least Platoon Length and Least Stopping Distance) in terms of achieved aerodynamic benefits, overall platoon length, and stopping distance. We then consider realistic conditions (in particular, changing road profiles as mentioned before) and investigate how to design a brake-by-wire controller present at each vehicle that accounts for this. We further extend our proposed cyber-physical approach by adding cooperative behavior. In particular, if an individual vehicle is unable to track its assigned deceleration, it coordinates with all others to avoid inter-vehicle collisions, for which we propose a vehicle-to-vehicle (V2V) communication strategy. Finally, we present a detailed evaluation of the proposed cyber-physical approach based on high-fidelity vehicle models in Matlab/Simulink. Even though more work is needed towards a real-life implementation, our simulation results demonstrate benefits by the proposed approach and, especially, its feasibility.
49

Machine Learning-Based Data-Driven Traffic Flow Estimation from Mobile Data / Maskininlärningsbaserad datadriven uppskattning av trafikflöden från mobila data

Hsu, Pei-Lun January 2021 (has links)
Comprehensive information on traffic flow is essential for vehicular emission monitoring and traffic control. However, such information is not observable everywhere and anytime on the road because of high installation costs and malfunctions of stationary sensors. In order to compensate for stationary sensors’ weakness, this thesis analyses an approach for inferring traffic flows from mobile data provided by INRIX, a commercial crowd-sourced traffic dataset with wide spatial coverage and high quality. The idea is to develop Artificial Neural Network (ANN)-based models to automatically extract relations between traffic flow and INRIX measurements, e.g., speed and travel time, from historical data considering temporal and spatial dependencies. We conducted experiments using four weeks of data from INRIX and stationary sensors on two adjacent road segments on the E4 highway in Stockholm. Models are validated via traffic flow estimation based on one week of INRIX data. Compared with the traditional approach that fits the stationary flow-speed relationship based on the multi-regime model, the new approach greatly improves the estimation accuracy. Moreover, the results indicate that the new approach’s models have better resistance to the drift of input variables and can decrease the deterioration of estimation accuracy on the road segment without a stationary sensor. Hence, the new approach may be more appropriate for estimating traffic flows on the nearby road segments of a stationary sensor. The approach provides a highly automated means to build models adaptive to datasets and improves estimation and imputation accuracy. It can also easily integrate new data sources to improve the models. Therefore, it is very suitable to be applied to Intelligent Transport Systems (ITS) for traffic monitor and control in the context of the Internet of Things (IoT) and Big Data. / Information om trafikflödet är nödvändig för övervakning av fordonsutsläpp och trafikstyrning. Trafikflöden kan dock inte observeras överallt och när som helst på vägen på grund av höga installationskostnader och t.ex. funktionsstörningar hos stationära sensorer. För att kompensera för stationära sensorers svagheter analyseras i detta arbete ett tillvägagångssätt för att estimera trafikflöden från mobila data som tillhandahålls av INRIX. Detta kommersiella dataset innehåller restider som kommer från användare av bl.a. färdnavigatorer i fordon och som har en bred rumslig täckning och hög kvalitet. Idén är att utveckla modeller baserade på artificiellt neuronnät för att automatiskt extrahera samband mellan trafikflödesdata och restidsdata från INRIX-mätningarna baserat på historiska data och med hänsyn till tidsmässiga och rumsliga beroenden. Vi utförde experiment med fyra veckors data från INRIX och från stationära sensorer på två intilliggande vägsegment på E4:an i Stockholm. Modellerna valideras med hjälp av estimering av trafikflöde baserat på en veckas INRIX- data. Jämfört med det traditionella tillvägagångssättet som anpassar stationära samband mellan trafikflöde och hastighet baserat på fundamentaldiagram, förbättrar det nya tillvägagångssättet noggrannheten avsevärt. Dessutom visar resultaten att modellerna i den nya metoden bättre hanterar avvikelser i ingående variabler och kan öka noggrannheten på estimatet för vägsegmentet utan stationär sensor. Den nya metoden kan därför vara lämplig för att uppskatta trafikflöden på vägsegment närliggande en stationär sensor. Metodiken ger ett automatiserat sätt att bygga modeller som är anpassade till datamängderna och som förbättrar noggrannheten vid estimering av trafikflöden. Den kan också enkelt integrera nya datakällor. Metodiken är lämplig att tillämpa på tillämpningar inom intelligenta transportsystem för trafikövervakning och trafikstyrning.
50

Simulation Studies of Impact of Heavy-Duty Vehicle Platoons on Road Traffic and Fuel Consumption

Johansson, Ingrid January 2018 (has links)
The demand for road freight transport continues to grow with the growing economy, resulting in increased fossil fuel consumption and emissions. At the same time, the fossil fuel use needs to decrease substantially to counteract the ongoing global warming. One way to reduce fuel consumption is to utilize emerging intelligent transport system (ITS) technologies and introduce heavy-duty vehicle (HDV) platooning, i.e. HDVs driving with small inter-vehicle gaps enabled by the use of sensors and controllers. It is of importance for transport authorities and industries to investigate the effects of introducing HDV platooning. Previous studies have investigated the potential benefits, but the effects in real traffic, both for the platoons and for the surrounding vehicles, have barely been explored. To further utilize ITS and optimize the platoons, information about the traffic situation ahead can be used to optimize the vehicle trajectories for the platoons. Paper I presents a dynamic programming-based optimal speed control including information of the traffic situation ahead. The optimal control is applied to HDV platoons in a deceleration case and the potential fuel consumption reduction is evaluated by a microscopic traffic simulation study with HDV platoons driving in real traffic conditions. The effects for the surrounding traffic are also analysed. Paper II and Paper III present a simulation platform to assess the effects of HDV platooning in real traffic conditions. Through simulation studies, the potential fuel consumption reduction by adopting HDV platooning on a real highway stretch is evaluated, and the effects for the other vehicles in the network are investigated. / Efterfrågan på godstransporter på väg fortsätter att öka i takt med den växande ekonomin, vilket resulterar i ökad förbrukning av fossila bränslen och ökade utsläpp. Samtidigt behöver användandet av fossila bränslen minska för att motverka den pågående globala uppvärmningen. Ett sätt för att minska bränsleförbrukningen är att utnyttja den teknik kring intelligenta transportsystem som är under utveckling och introducera lastbilskonvojer, det vill säga lastbilar som använder sensorer och regulatorer för att kunna köra med korta avstånd mellan sig. För transportföretag och -myndigheter är det viktigt att undersöka effekterna av att införa lastbilskonvojkörning. Tidigare studier har undersökt de möjliga fördelarna, men effekterna vid körning i trafik, både för konvojerna och för omgivande fordon, är outforskade. För att ytterligare utnyttja intelligenta transportsystem och optimera konvojerna kan information om trafiksituationen längre fram på vägen användas för att optimera konvojernas körning. Artikel I presenterar en optimal hastighetsregulator baserad på dynamisk programmering och som inkluderar information om trafiksituationen längre fram. Den optimala regulatorn appliceras på lastbilskonvojer under ett inbromsningsscenario och den potentiella minskningen i bränsleförbrukning utvärderas genom en mikroskopisk trafiksimuleringsstudie där lastbilskonvojerna kör i verkliga trafikförhållanden. Effekterna för omgivande fordon är också analyserade.Artikel II och artikel III presenterar en simuleringsplattform för att utvärdera effekterna av lastbilskonvojkörning i verkliga trafikförhållanden. Genom simuleringsstudier analyseras den potentiella bränsleförbrukningsminskningen då lastbilskonvojer körs på en verklig motorvägssträcka och effekterna för de övriga fordonen på vägen undersöks. / <p>QC 20180516</p>

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