155 research outputs found

    Safety Applications and Measurement Tools for Connected Vehicles

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    L'abstract è presente nell'allegato / the abstract is in the attachmen

    Development and Performance Evaluation of Network Function Virtualization Services in 5G Multi-Access Edge Computing

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    L'abstract è presente nell'allegato / the abstract is in the attachmen

    A Simulation Framework for Traffic Safety with Connected Vehicles and V2X Technologies

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    With the advancement in automobile technologies, existing research shows that connected vehicle (CV) technologies can provide better traffic safety through Surrogate Safety Measure (SSM). CV technologies involves two network systems: traffic network and wireless communication network. We found that the research in the wireless communication network for CV did not interact properly with the research in SSM in transportation network, and vice versa. Though various SSM has been proposed in previous studies, a few of them have been tested in simulation software in limited extent. On the other hand, A large body of researchers proposed various communication architecture for CV technologies to improve communication performance. However, none of them tested the advanced SSM in their proposed architecture. Hence, there exists a research gap between these two communities, possibly due to difference in research domain. In this study, we developed a V2X simulation framework using SUMO, OMNeT++ and Veins for the development and testing of various SSM algorithms in run time simulation. Our developed framework has three level of communication ( CV to RSU To TS) system and is applicable for large traffic network that can have mixed traffic system (CV and non-CV), multiple road side unit (RSUs), and traffic server (TS). Moreover, the framework can be used to test SSM algorithms for other traffic networks without doing much modification. Our developed framework will be publicly available for its further development and optimization

    A Framework for Quality of Service in Vehicle-to-Pedestrian Safety Communication

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    Vehicle-to-Everything (V2X) communication has emerged as an important mechanism to improve the safety and efficiency of road traffic. V2X communication encompasses Vehicle-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I), and Vehicle-to-Pedestrian (V2P) communication. Among these types, the V2P communication efforts continue to be in the preliminary stage and lack a rounded approach towards the development of V2P systems. V2P involves communication between vehicles and a wide variety of Vulnerable Road Users (VRUs), such as pedestrians, bicyclists, mopeds, etc. The V2X systems were originally developed only for V2V and V2I when solely the vehicle characteristics were in focus. However, effective V2P system design needs to consider the characteristics of VRUs. The differing characteristics of VRUs have given rise to many questions while adapting to the V2V communication model for the V2P system. This dissertation addresses three aspects pertaining to the development of the V2P safety system. The first aspect involves a systematic design of a V2P system using a holistic approach. This dissertation proposes a V2P design framework based on various categories of inputs that are required for the design of an effective V2P system. This framework improves the understanding of the V2P system requirements and helps make the design process more systematic. The second aspect is the network performance of the V2X network in the presence of a large number of VRUs. This dissertation proposes MC-COCO4V2P, which is an energy-efficient pedestrian clustering mechanism for network congestion mitigation. MC-COCO4V2P improves network performance by reducing the pedestrian-generated safety messages. It also improves the battery life of the pedestrian devices in the process. The third aspect involves the reliability of communication between a pair of a vehicle and a pedestrian that are on the verge of collision. This dissertation classifies such crucial communication as the one requiring the highest priority even among the exchange of critical safety messages. It proposes a mechanism enabling the surrounding nodes to reduce the communication priority temporarily. This results in preferred medium access for the pair resulting in higher Quality-of-Service (QoS) for the crucial communication.Die Kommunikation zwischen Verkehrsteilnehmern (V2X) hat sich zu einem wichtigen Mechanismus zur Verbesserung der Sicherheit und Effizienz des Straßenverkehrs entwickelt. Obwohl die V2X-Kommunikation prinzipiell die Kommunikation zwischen Fahrzeugen (V2V), zwischen Fahrzeug und Infrastruktur (V2I) sowie zwischen Fahrzeug und Fußgänger (V2P) umfasst, sind Ansätze zur V2P-Kommunikation weiterhin in einem sehr frühen Stadium und lassen einen umfassenden Ansatz für die Entwicklung von V2P-Systemen vermissen. V2P umfasst im Detail die Kommunikation zwischen Fahrzeugen und einer Vielzahl von gefährdeten Verkehrsteilnehmern (VRUs), wie beispielsweise Fußgänger, Radfahrer oder Mopeds. V2X-Systeme wurden ursprünglich nur für V2V- und V2I-Kommunikation entwickelt, wobei ausschließlich die Fahrzeugeigenschaften im Fokus standen. Ein effektives V2P-Systemdesign muss jedoch auch die Eigenschaften von VRUs berücksichtigen, die bei der Berücksichtigung der V2P-Kommunikation in einem V2X-System viele Fragen aufwerfen. Diese Dissertation befasst sich mit drei Aspekten im Zusammenhang mit der Entwicklung eines V2P-Systems. Der erste Aspekt betrifft die systematische Konzeption eines V2P-Systems nach einem ganzheitlichen Ansatz. Diese Dissertation schlägt einen V2P-Entwurfsrahmen vor, der auf verschiedenen Eingangsgrößen basiert, die für die Entwicklung eines effektiven V2P-Systems erforderlich sind. Dieser Entwurfsrahmen verbessert das Verständnis der V2P-Systemanforderungen und trägt dazu bei, den Entwurfsprozess systematischer zu gestalten. Der zweite Aspekt betrifft die Leistung des V2X-Netzes, wenn eine große Anzahl von VRUs präsent ist. Diese Dissertation schlägt hierfür MC-COCO4V2P vor, einen energieeffizienten Clustering-Mechanismus für Fußgänger zur Eindämmung der Netzüberlastung. MC-COCO4V2P verbessert die Netzleistung, indem die Anzahl der von Fußgängern generierten Sicherheitsmeldungen reduziert wird. Damit wird zudem die Batterielebensdauer der von den Fußgängern genutzten Geräte verbessert. Der dritte Aspekt betrifft die Zuverlässigkeit der Kommunikation zwischen einem Fahrzeug und einem Fußgänger, die kurz vor einem Zusammenstoß stehen. Diese Dissertation stuft eine so wichtige Kommunikation als diejenige ein, die selbst beim Austausch anderer kritischer Sicherheitsnachrichten die höchste Priorität bekommt. Es wird ein Mechanismus vorgeschlagen, der es den umgebenden Verkehrsteilnehmern ermöglicht, ihre Kommunikationspriorität vorübergehend zu verringern. Dies führt zu einem bevorzugten Medienzugriff für die durch eine Kollision gefährdeten Verkehrsteilnehmer, was zu einer höheren Dienstgüte (QoS) für deren Kommunikation führt.Pedestrians and bicyclists, also known as Vulnerable Road Users (VRUs), are one of the weakest components of Intelligent Transportation Systems from a safety perspective. However, with the advent of new communication technologies, VRU protection may no longer be dependent solely on the vehicle’s safety systems. VRUs may share their location information with the surrounding vehicles to increase awareness of their presence. Such communication among vehicles and VRUs is referred to as Vehicle-to-Pedestrian (V2P) communication. Although the V2P system may be built upon the existing Vehicle-to-Vehicle communication system, it has its own set of challenges, such as different VRU mobility characteristics, energy-constrained devices, and VRU density. Therefore, there needs to be a V2P system model which is adapted to the VRU characteristics. This dissertation tackles this challenge by proposing a framework that enables scalability, reliability, and energy efficiency for VRU communication

    Open Platforms for Connected Vehicles

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    L'abstract è presente nell'allegato / the abstract is in the attachmen

    Situational Awareness Enhancement for Connected and Automated Vehicle Systems

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    Recent developments in the area of Connected and Automated Vehicles (CAVs) have boosted the interest in Intelligent Transportation Systems (ITSs). While ITS is intended to resolve and mitigate serious traffic issues such as passenger and pedestrian fatalities, accidents, and traffic congestion; these goals are only achievable by vehicles that are fully aware of their situation and surroundings in real-time. Therefore, connected and automated vehicle systems heavily rely on communication technologies to create a real-time map of their surrounding environment and extend their range of situational awareness. In this dissertation, we propose novel approaches to enhance situational awareness, its applications, and effective sharing of information among vehicles.;The communication technology for CAVs is known as vehicle-to-everything (V2x) communication, in which vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) have been targeted for the first round of deployment based on dedicated short-range communication (DSRC) devices for vehicles and road-side transportation infrastructures. Wireless communication among these entities creates self-organizing networks, known as Vehicular Ad-hoc Networks (VANETs). Due to the mobile, rapidly changing, and intrinsically error-prone nature of VANETs, traditional network architectures are generally unsatisfactory to address VANETs fundamental performance requirements. Therefore, we first investigate imperfections of the vehicular communication channel and propose a new modeling scheme for large-scale and small-scale components of the communication channel in dense vehicular networks. Subsequently, we introduce an innovative method for a joint modeling of the situational awareness and networking components of CAVs in a single framework. Based on these two models, we propose a novel network-aware broadcast protocol for fast broadcasting of information over multiple hops to extend the range of situational awareness. Afterward, motivated by the most common and injury-prone pedestrian crash scenarios, we extend our work by proposing an end-to-end Vehicle-to-Pedestrian (V2P) framework to provide situational awareness and hazard detection for vulnerable road users. Finally, as humans are the most spontaneous and influential entity for transportation systems, we design a learning-based driver behavior model and integrate it into our situational awareness component. Consequently, higher accuracy of situational awareness and overall system performance are achieved by exchange of more useful information

    Robust Low-Cost Multiple Antenna Processing for V2V Communication

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    Cooperative V2V communication with frequent, periodic broadcast of messages between vehicles is a key enabler of applications that increase traffic safety and traffic efficiency on roads. Such broadcast V2V communication requires an antenna system with omnidirectional coverage, which is difficult to achieve using a single antenna element. For a mounted, omnidirectional antenna on a vehicle is distorted by the vehicle body, and exhibits a nonuniform directional pattern with low gain in certain directions. The thesis addresses this problem by developing schemes that employ multiple antennas (MAs) to achieve an effective radiation pattern with omnidirectional characteristics at both the transmit- and the receive-side. To ensure robust communication, the MA schemes are designed to minimize the burst error probability of several consecutive status messages in a scarce multipath environment with a dominant path between vehicles.First, at the receive-side, we develop a hybrid analog-digital antenna combiner. The analog part of the combiner is composed of low-cost analog combining networks (ACNs) of phase shifters that do not depend on channel stateinformation (CSI), while the digital part uses maximal ratio combining. We show that the optimal phase slopes of the analog part of the combiner (i.e., the phase slopes that minimize the burst error probability) are the same found under the optimization of a single ACN, which was done in earlier work. We then show how directional antennas can be employed in this context to achieve an effective omnidirectional radiation pattern of the antenna system that is robust in all directions of arrival of received signals.Secondly, at the transmit-side, we develop two low-cost analog MA schemes, an analog beamforming network (ABN) of phase shifters, and an antenna switching network (ASN), for the case when receivers employ the ACN or the hybrid combiner. Both schemes are shown to achieve an effective radiation pattern with improved omnidirectional characteristics at the transmit-side without relying on CSI.Thirdly, the schemes above were developed assuming that all vehicles broadcast their messages with the same fixed period. Therefore, we tackle the practical scenario when different vehicles use different and potentially varying broadcast periods. We show that the phase slopes of the MA schemes at the receiver and/or transmitter can be designed to support multiple broadcast periods.\ua0Lastly, the optimal phase slopes of the MA schemes were analytically derived under a worst-case propagation corresponding to a dominant path with an angle of departure, and an angle of arrival that are approximately non-varying over the time it takes to transmit and receive several packets. We relax this assumption and study the system performance under a time-varying dominant component instead. We derive a design rule that yields robust phase slopes that effectively mitigate the losses due to the time-variation of the dominant path
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