1,089 research outputs found

    Infraestrutura de beira de estrada para apoio a sistemas cooperativos e inteligentes de transportes

    Get PDF
    The growing need of mobility along with the evolution of the automotive industry and the massification of the personal vehicle amplifies some of the road-related problems such as safety and traffic congestion. To mitigate such issues, the evolution towards cooperative communicating technologies and autonomous systems is considered a solution to overcome the human physical limitations and the limited perception horizon of on-board sensors. Short-range vehicular communications such as Vehicle-to-Vehicle or Vehicle-to-Infrastructure (ETSI ITS-G5) in conjunction with long-range cellular communications (LTE,5G) and standardized messages, emerge as viable solutions to amplify the benefits that standalone technologies can bring to the road environment, by covering a wide array of applications and use cases. In compliance with the standardization work from European Telecommunications Standards Institute (ETSI), this dissertation describes the implementation of the collective perception service in a real road infrastructure to assist the maneuvers of autonomous vehicles and provide information to a central road operator. This work is focused on building standardized collective perception messages (CPM) by retrieving information from traffic classification radars (installed in the PASMO project) for local dissemination using ETSI ITS-G5 radio technology and creating a redundant communication channel between the road infrastructure and a central traffic control centre, located at the Instituto de TelecomunicaƧƵes - Aveiro, taking advantage of cellular, point-to-point radio links and optical fiber communications. The output of the messages are shown to the user by a mobile application. The service is further improved by building an algorithm for optimizing the message dissemination to improve channel efficiency in more demanding scenarios. The results of the experimental tests showed that the time delay between the production event of the collective perception message and the reception by other ITS stations is within the boundaries defined by ETSI standards. Moreover, the algorithm for message dissemination also shows to increase radio channel efficiency by limiting the number of objects disseminated by CPM messages. The collective perception service developed and the road infrastructure are therefore, a valuable asset to provide useful information for improving road safety and fostering the deployment of intelligent cooperative transportation systems.A crescente necessidade de mobilidade em paralelo com a evoluĆ§Ć£o da indĆŗstria automĆ³vel e com a massificaĆ§Ć£o do uso de meios de transportes pessoais, tĆŖm vindo a amplificar alguns problemas dos transportes rodoviĆ”rios, tais como a seguranƧa e o congestionamento do trĆ”fego. Para mitigar estas questƵes, a evoluĆ§Ć£o das tecnologias de comunicaĆ§Ć£o cooperativas e dos sistemas autĆ³nomos Ć© vista como uma potencial soluĆ§Ć£o para ultrapassar limitaƧƵes dos condutores e do horizonte de perceĆ§Ć£o dos sensores veĆ­culares. ComunicaƧƵes de curto alcance, tais como VeĆ­culo-a-VeĆ­culo ou VeĆ­culo-a-Infrastrutura (ETSI ITS-G5), em conjunto com comunicaƧƵes mĆ³veis de longo alcance (LTE,5G) e mensagens padrĆ£o, emergem como soluƧƵes viĆ”veis para amplificar todos os beneficios que tecnologias independentes podem trazer para o ambiente rodoviĆ”rio, cobrindo um grande leque de aplicaƧƵes e casos de uso da estrada. Em conformidade com o trabalho de padronizaĆ§Ć£o da European Telecommunications Standards Institute, esta dissertaĆ§Ć£o descreve a implementaĆ§Ć£o do serviƧo de perceĆ§Ć£o coletiva, numa infrastrutura rodoviĆ”ria real, para suporte a manobras de veĆ­culos autĆ³nomos e para fornecer informaƧƵes aos operadores de estradas. Este trabalho foca-se na construĆ§Ć£o de mensagens de perceĆ§Ć£o coletiva a partir de informaĆ§Ć£o gerada por radares de classificaĆ§Ć£o de trĆ”fego (instalados no Ć¢mbito do projeto PASMO) para disseminaĆ§Ć£o local usando a tecnologia rĆ”dio ETSI ITS-G5 e criando um canal de comunicaĆ§Ć£o redundante entre a infraestrutura rodĆ³viaria e um centro de controlo de trĆ”fego localizado no Instituto de TelecomunicaƧƵes - Aveiro, usando para isso: redes mĆ³veis, ligaƧƵes rĆ”dio ponto a ponto e fibra Ć³tica. O conteĆŗdo destas messagens Ć© mostrado ao utilizador atravĆ©s de uma aplicaĆ§Ć£o mĆ³vel. O serviƧo Ć© ainda melhorado, tendo-se para tal desenvolvido um algoritmo de otimizaĆ§Ć£o de disseminaĆ§Ć£o das mensagens, tendo em vista melhorar a eficiĆŖncia do canal de transmissĆ£o em cenĆ”rios mais exigentes. Os resultados dos testes experimentais efetuados revelaram que o tempo de atraso entre o evento de produĆ§Ć£o de uma mensagem de perceĆ§Ć£o coletiva e a receĆ§Ć£o por outra estaĆ§Ć£o ITS, usando comunicaƧƵes ITS-G5, se encontra dentro dos limites definidos pelos padrƵes da ETSI. AlĆ©m disso, o algoritmo para disseminaĆ§Ć£o de mensagens tambĆ©m mostrou aumentar a eficiĆŖncia do canal de rĆ”dio, limitando o nĆŗmero de objetos disseminados pelas mesmas. Assim, o serviƧo de perceĆ§Ć£o coletiva desenvolvido poderĆ” ser uma ferramenta valiosa, contribuindo para o aumento da seguranƧa rodĆ³viaria e para a disseminaĆ§Ć£o da utilizaĆ§Ć£o dos sistemas cooperativos de transporte inteligente.Mestrado em Engenharia EletrĆ³nica e TelecomunicaƧƵe

    ēµ±åˆåž‹čµ°č”Œę™‚車äø”重量č؈ęø¬č£…ē½®ć®é–‹ē™ŗćØ車äø”é‡é‡ć‚’č€ƒę…®ć—ćŸäŗ¤é€šęµē‰¹ę€§ć®åˆ†ęž

    Get PDF
    This study attempts to explore empirically how gross vehicle weight (GVW) will affect traffic flow characteristics in both free-flow and vehicle following situations. The success of the study is highly dependent on the empirical data provided by the traffic datacollection system. Currently, many kinds of systems or devices are available which measure or monitor or enforce traffic dedicatedly. The use of these dedicated or nonintegrated systems or devices in traffic data-collection or monitoring and traffic enforcement is useful in certain application, especially when only dedicated parameter is considered. However, these devices may have limited measurement capabilities and unsuitable for this study, where the devices are incapable of simultaneously measuring all essential traffic and vehicle parameters such as speed, headway as well as weight in real-time. The use of these dedicated devices for this study will result in data inconsistency and incomprehensive measurable traffic parameters. Thus, a comprehensive and continuous traffic data-collection system based on weigh-inmotion technology has been developed and installed at one of the federal roads in Malaysia for study purposes. The developed system is capable of simultaneously and continuously measuring large sample and all essential traffic and vehicle parameters in real-time. It also uses the minimum number of sensors necessary to provide the maximum number of various traffic and vehicle parameters. Statistical analysis was then performed to the collected data to quantify that the gross vehicle weight can have a significant effect in traffic flow characteristics in both free flow and following situations. The results lead to explore the driver behavior in controlling the vehicle from two different perspective: driverā€™s visual input and vehicle dynamics capability. The first empirical analysis results showed that statistically for each type of heavy vehicle, there was a significant relationship between free flow speed of a heavy vehicle and its GVW. Specifically, the results suggest that the mean and variance of free flow speed decrease with an increase GVW by the amount unrelated to size and shape for all GVW range. Then, based on the 85th percentile principle, this study proposed a new concept for setting differential speed limit for heavy vehicle by incorporating GVW where a different speed limit is imposed to the heavy vehicle according to its GVW. The second empirical analysis results showed that how GVW of following vehicle and size of leading vehicle will affect the driver behavior in controlling their speed under different compositions of leader-follower pairs in a car-following situation. The main findings of this study are when we incorporate the vehicle dynamicā€™s capability in a carfollowing situation, the GVW of following vehicle and the size of leading vehicle were significant sources of variation in following vehicle speed and relative speed, and their interaction influence the driver behavior in controlling the speed.The third study investigated empirically how different composition of leader-follower pairs will affect time headway with the focus on following vehicle (FV) GVW and leading vehicle (LV) size. The results from statistical analysis were quite revealing in terms of quantifying that the GVW of FV and the class of LV were a significant source of variation in time headway. Based on these empirical results, the study suggests a preferred minimum headway model from driver perspective incorporating heavy vehicle size and GVW. The proposed model also suggests the selection of the optimum value of preferred minimum headway based on percentile value if human reaction time, public support and traffic flow interference are to be considered. Based on these empirical analyses, it can be concluded that, the main findings of this study are when we incorporate the vehicle dynamics capability in a traffic flow study, the gross vehicle weight should be considered as one of the variable of interests to obtain more rational results

    Prospectus, December 4, 2013

    Get PDF
    TIPS FOR GETTING THROUGH FINAL EXAMS; Texting at stoplight an accident waiting to happen; Transfer tips for students; Tips to earn extra money for the holidays; Winter weather preparedness tips; Public Safety on kitchen safety tips; Gender discrimination in collegiate athletics; \u27Selfie\u27 as word of the year is a fitting self-portrait; Safety shifting to automatic; Volleyball team ends season stronghttps://spark.parkland.edu/prospectus_2013/1023/thumbnail.jp

    Dynamic Message Sign and Diversion Traffic Optimization

    Get PDF
    This dissertation proposes a Dynamic Message Signs (DMS) diversion control system based on principles of existing Advanced Traveler Information Systems and Advanced Traffic Management Systems (ATMS). The objective of the proposed system is to alleviate total corridor traffic delay by choosing optimized diversion rate and alternative road signal-timing plan. The DMS displays adaptive messages at predefined time interval for guiding certain number of drivers to alternative roads. Messages to be displayed on the DMS are chosen by an on-line optimization model that minimizes corridor traffic delay. The expected diversion rate is assumed following a distribution. An optimization model that considers three traffic delay components: mainline travel delay, alternative road signal control delay, and the travel time difference between the mainline and alternative roads is constructed. Signal timing parameters of alternative road intersections and DMS message level are the decision variables; speeds, flow rates, and other corridor traffic data from detectors serve as inputs of the model. Traffic simulation software, CORSIM, served as a developmental environment and test bed for evaluating the proposed system. MATLAB optimization toolboxes have been applied to solve the proposed model. A CORSIM Run-Time-Extension (RTE) has been developed to exchange data between CORSIM and the adopted MATLAB optimization algorithms (Genetic Algorithm, Pattern Search in direct search toolbox, and Sequential Quadratic Programming). Among the three candidate algorithms, the Sequential Quadratic Programming showed the fastest execution speed and yielded the smallest total delays for numerical examples. TRANSYT-7F, the most credible traffic signal optimization software has been used as a benchmark to verify the proposed model. The total corridor delays obtained from CORSIM with the SQP solutions show average reductions of 8.97%, 14.09%, and 13.09% for heavy, moderate and light traffic congestion levels respectively when compared with TRANSYT-7F optimization results. The maximum model execution time at each MATLAB call is fewer than two minutes, which implies that the system is capable of real world implementation with a DMS message and signal update interval of two minutes

    A framework for the synergistic integration of fully autonomous ground vehicles with smart city

    Get PDF
    Most of the vehicle manufacturers aim to deploy level-5 fully autonomous ground vehicles (FAGVs) on city roads in 2021 by leveraging extensive existing knowledge about sensors, actuators, telematics and Artificial Intelligence (AI) gained from the level-3 and level-4 autonomy. FAGVs by executing non-trivial sequences of events with decimetre-level accuracy live in Smart City (SC) and their integration with all the SC components and domains using real-time data analytics is urgent to establish better swarm intelligent systems and a safer and optimised harmonious smart environment enabling cooperative FAGVs-SC automation systems. The challenges of urbanisation, if unmet urgently, would entail severe economic and environmental impacts. The integration of FAGVs with SC helps improve the sustainability of a city and the functional and efficient deployment of hand over wheels on robotized city roads with behaviour coordination. SC can enable the exploitation of the full potential of FAGVs with embedded centralised systems within SC with highly distributed systems in a concept of Automation of Everything (AoE). This paper proposes a synergistic integrated FAGV-SC holistic framework - FAGVinSCF in which all the components of SC and FAGVs involving recent and impending technological advancements are moulded to make the transformation from today's driving society to future's next-generation driverless society smoother and truly make self-driving technology a harmonious part of our cities with sustainable urban development. Based on FAGVinSCF, a simulation platform is built both to model the varying penetration levels of FAGV into mixed traffic and to perform the optimal self-driving behaviours of FAGV swarms. The results show that FAGVinSCF improves the urban traffic flow significantly without huge changes to the traffic infrastructure. With this framework, the concept of Cooperative Intelligent Transportation Systems (C-ITS) is transformed into the concept of Automated ITS (A-ITS). Cities currently designed for cars can turn into cities developed for citizens using FAGVinSCF enabling more sustainable cities

    Usability of Urban Air Mobility: Quantitative and Qualitative Assessments of Usage in Emergency Situations

    Get PDF
    The purpose of these four studies was to determine participantsā€™ willingness to support the use of urban air mobility (UAM) in response to natural disasters, along with the preferred locations to establish vertiports. Study 1 assessed the willingness to support using a mixed factorial design. The findings demonstrated strong, robust support for the use of UAM when responding to natural disasters. Study 2 worked to create and validate a scale that could assess vertiports\u27 current and proposed locations. The Vertiport Usability Scale was developed and shown to have strong psychometric properties to validly assess vertiport locations through a multi-stage process. Study 3 used the Vertiport Usability Scale to understand the most highly preferred locations for vertiports in three conditions from a multi-stage process: temporary disaster locations, permanent disaster locations, and permanent consumer locations. Study 4 was conducted using qualitative methods to complement the earlier quantitative approaches. Through an initial survey and follow-on interview, three themes emerged related to UAM in response to natural disasters and vertiports: 1) human involvement in UAM operations, 2) scenarios for usage, and 3) setup and deployment of vehicles

    Proceedings, MSVSCC 2012

    Get PDF
    Proceedings of the 6th Annual Modeling, Simulation & Visualization Student Capstone Conference held on April 19, 2012 at VMASC in Suffolk, Virginia
    • ā€¦
    corecore