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

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

Connected Car: technologies, issues, future trends

The connected car -a vehicle capable of accessing to the Internet, of communicating with smart devices as well as other cars and road infrastructures, and of collecting real-time data from multiple sources- is likely to play a fundamental role in the foreseeable Internet Of Things. In a context ruled by very strong competitive forces, a significant amount of car manufacturers and software and hardware developers have already embraced the challenge of providing innovative solutions for new generation vehicles. Today’s cars are asked to relieve drivers from the most stressful operations needed for driving, providing them with interesting and updated entertainment functions. In the meantime, they have to comply to the increasingly stringent standards about safety and reliability. The aim of this paper is to provide an overview of the possibilities offered by connected functionalities on cars and the associated technological issues and problems, as well as to enumerate the currently available hardware and software solutions and their main features

Design, Implementation and a Pilot Study of Mobile Framework for Pedestrian Safety Using Smartphone Sensors

Pedestrian distraction from smartphones is a serious social problem that caused an ever increasing number of fatalities especially as virtual reality (VR) games have gained popularity recently. In this thesis, we present the design, implementation, and a pilot study of WiPedCross, a WiFi direct-based pedestrian safety system that senses and evaluates a risk, and alerts accordingly the user to prevent traffic accidents. In order to develop a non-intrusive, accurate, and energy-efficient pedestrian safety system, a number of technical challenges are addressed: to enhance the positioning accuracy of the user for precise risk assessment, a map-matching algorithm based on a Hidden Markov Model is designed; to minimize energy consumption, an adaptive scheme is developed that dynamically activates the GPS module of a phone according to pedestrian walking speed and the locations of nearby crosswalks; to suppress false alarms, a novel algorithm is developed to accurately identify the user-phone-viewing activity so that collision probability assessment is triggered only when the pedestrian is walking while viewing his or her phone. The prototype of the proposed framework is implemented on an Android platform for a pilot study to evaluate feasibility, reliability, and validity of WiPedCross. Extensive experiments are performed in a parking lot and the results demonstrate that WiPedCross assesses the collision probability effectively and provides warning to the user in a timely manner. The system modules of the proposed framework are expected to benefit numerous other pedestrian safety apps

Cryptography and Privacy in Vehicular Communication Networks

Wireless communication technologies can support dynamic networks between vehicles, pedestrians and roadside infrastructure called Vehicular Ad hoc Networks (VANETs). Wireless communication over VANETs allows for several communications scenarios — between vehicles, between vehicles and infrastructure, and between vehicles and pedestrians, among others — collectively known as Vehicle-to-Everything (V2X) communication. Fast wireless communication allows vehicles to communicate over long distances, improving a driver's perception compared to relying on human senses alone. Computerised automated decisions made in response to a wireless message also allow for a lifesaving decision to be much faster than the average human's reaction time can allow. A report by the United Stated Department of Transport shows that applications which use V2X communication, such as Emergency Brake Warning, Left-turn Assist, and Lane-change Assist, can help reduce unimpaired vehicular collisions by as much as 80%. Further, V2X applications like Cooperative Platooning and Emergency Vehicle Path Clearing offer improved fuel efficiency, traffic efficiency, and faster response times for emergency vehicles. For these reasons, V2X communication has garnered significant interest from the automotive industry, the research community and governments in recent years. While V2X communication offers many benefits, unsecured V2X communication can also be exploited by adversaries to increase traffic congestion, track vehicles and people, and even induce vehicular crashes as we show in this thesis. For these reasons, it is necessary to secure VANETs and V2X communication. While security standards for V2X communication exist, their restrictive requirements can make implementing efficient applications difficult. Further, V2X application designers often design applications with little regard to security (incorrectly assuming that the standardised security measures provide adequate security regardless of the underlying application), resulting in applications that violate the security standards imposed restrictions, and leading to applications which are not secure. The Emergency Brake Warning application is one application affected by this disconnect between application designers and V2X security standards. This thesis introduces the uninitiated reader to V2X communication, V2X applications, and V2X security standards while describing the necessary cryptography along the way. Then we discuss the working and limitations of current proposals for the Emergency Brake Warning application before describing EBW-PoF, a novel protocol for the same application, that overcomes these shortcomings. Finally, we discuss EBW-PoF's security, performance, and limitations

Automotive applications of high precision GNSS

This thesis aims to show that Global Navigation Satellite Systems (GNSS) positioning can play a significant role in the positioning systems of future automotive applications. This is through the adoption of state-of-the-art GNSS positioning technology and techniques, and the exploitation of the rapidly developing vehicle-to-vehicle concept. The merging together of these two developments creates greater performance than can be achieved separately. The original contribution of this thesis comes from this combination: Through the introduction of the Pseudo-VRS concept. Pseudo-VRS uses the princples of Network Real Time Kinematic (N-RTK) positioning to share GNSS information between vehicles, which enables absolute vehicle positioning. Pseudo-VRS is shown to improve the performance of high precision GNSS positioning for road vehicles, through the increased availability of GNSS correction messages and the rapid resolution of the N-RTK fixed solution. Positioning systems in the automotive sector are dominated by satellite-based solutions provided by GNSS. This has been the case since May 2001, when the United States Department of Defense switched off Selective Availability, enabling significantly improved positioning performance for civilian users. The average person most frequently encounters GNSS when using electronic personal navigation devices. The Sat Nav or GPS Navigator is ubiquitous in modern societies, where versions can be found on nomadic devices such as smartphones and dedicated personal navigation devices, or built in to the dashboards of vehicles. Such devices have been hugely successful due to their intrinsic ability to provide position information anywhere in the world with an accuracy of approximately 10 metres, which has proved ideal for general navigation applications. There are a few well known limitations of GNSS positioning, including anecdotal evidence of incorrect navigation advice for personal navigation devices, but these are minor compared to the overall positioning performance. Through steady development of GNSS positioning devices, including the integration of other low cost sensors (for instance, wheel speed or odometer sensors in vehicles), and the development of robust map matching algorithms, the performance of these devices for navigation applications is truly incredible. However, when tested for advanced automotive applications, the performance of GNSS positioning devices is found to be inadequate. In particular, in the most advanced fields of research such as autonomous vehicle technology, GNSS positioning devices are relegated to a secondary role, or often not used at all. They are replaced by terrestrial sensors that provide greater situational awareness, such as radar and lidar. This is due to the high performance demand of such applications, including high positioning accuracy (sub-decimetre), high availability and continuity of solutions (100%), and high integrity of the position information. Low-cost GNSS receivers generally do not meet such requirements. This could be considered an enormous oversight, as modern GNSS positioning technology and techniques have significantly improved satellite-based positioning performance. Other non-GNSS techniques also have their limitations that GNSS devices can minimise or eliminate. For instance, systems that rely on situational awareness require accurate digital maps of their surroundings as a reference. GNSS positioning can help to gather this data, provide an input, and act as a fail-safe in the event of digital map errors. It is apparent that in order to deliver advanced automotive applications - such as semi- or fully-autonomous vehicles - there must be an element of absolute positioning capability. Positioning systems will work alongside situational awareness systems to enable the autonomous vehicles to navigate through the real world. A strong candidate for the positioning system is GNSS positioning. This thesis builds on work already started by researchers at the University of Nottingham, to show that N-RTK positioning is one such technique. N-RTK can provide sub-decimetre accuracy absolute positioning solutions, with high availability, continuity, and integrity. A key component of N-RTK is the availability of real-time GNSS correction data. This is typically delivered to the GNSS receiver via mobile internet (for a roving receiver). This can be a significant limitation, as it relies on the performance of the mobile communications network, which can suffer from performance degradation during dynamic operation. Mobile communications systems are expected to improve significantly over the next few years, as consumers demand faster download speeds and wider availability. Mobile communications coverage already covers a high percentage of the population, but this does not translate into a high percentage of a country's geography. Pockets of poor coverage, often referred to as notspots, are widespread. Many of these notspots include the transportation infrastructure. The vehicle-to-vehicle concept has made significant forward steps in the last few years. Traditionally promoted as a key component of future automotive safety applications, it is now driven primarily by increased demand for in-vehicle infotainment. The concept, which shares similarities with the Internet of Things and Mobile Ad-hoc Networks, relies on communication between road vehicles and other road agents (such as pedestrians and road infrastructure). N-RTK positioning can take advantage of this communication link to minimise its own communications-related limitations. Sharing GNSS information between local GNSS receivers enables better performance of GNSS positioning, based on the principles of differential GNSS and N-RTK positioning techniques. This advanced concept is introduced and tested in this thesis. The Pseudo VRS concept follows the protocols and format of sharing GNSS data used in N-RTK positioning. The technique utilises the latest GNSS receiver design, including multiple frequency measurements and high quality antennas

Vehicle-to-vehicle communication: design, performance, and disruption mitigation in real-world environment

This thesis investigates the performance of 802.11p-based V2V communication in real-life scenarios, and explores potential practical applications such as GNSS correction data broadcasting to improve the positioning accuracy of nearby vehicles, and enhancing communication robustness by preemptively predicting potential disruptions with the assistance of Machine Learning (ML) models. A custom V2V On-board Unit (OBU) hardware platform was developed, and real- world multi-vehicle outdoor experiments were planned and carried out. The collected data was examined and used to train a number of ML models, and their performance was compared. The experiments revealed that the custom OBU was fully functional, and signal quality and communication range were observed to be affected by real-world imperfections. The GNSS correction data broadcasting was shown to notably increase the positioning accuracy of nearby vehicles, and the ML models trained from Key Performance Indicators (KPIs) demonstrated excellent prediction accuracy, allowing pre-emptive actions to be taken to reduce the downtime from communication disruption

Vehicle-to-vehicle communication: design, performance, and disruption mitigation in real-world environment

This thesis investigates the performance of 802.11p-based V2V communication in real-life scenarios, and explores potential practical applications such as GNSS correction data broadcasting to improve the positioning accuracy of nearby vehicles, and enhancing communication robustness by preemptively predicting potential disruptions with the assistance of Machine Learning (ML) models. A custom V2V On-board Unit (OBU) hardware platform was developed, and real- world multi-vehicle outdoor experiments were planned and carried out. The collected data was examined and used to train a number of ML models, and their performance was compared. The experiments revealed that the custom OBU was fully functional, and signal quality and communication range were observed to be affected by real-world imperfections. The GNSS correction data broadcasting was shown to notably increase the positioning accuracy of nearby vehicles, and the ML models trained from Key Performance Indicators (KPIs) demonstrated excellent prediction accuracy, allowing pre-emptive actions to be taken to reduce the downtime from communication disruption

Automotive applications of high precision GNSS

This thesis aims to show that Global Navigation Satellite Systems (GNSS) positioning can play a significant role in the positioning systems of future automotive applications. This is through the adoption of state-of-the-art GNSS positioning technology and techniques, and the exploitation of the rapidly developing vehicle-to-vehicle concept. The merging together of these two developments creates greater performance than can be achieved separately. The original contribution of this thesis comes from this combination: Through the introduction of the Pseudo-VRS concept. Pseudo-VRS uses the princples of Network Real Time Kinematic (N-RTK) positioning to share GNSS information between vehicles, which enables absolute vehicle positioning. Pseudo-VRS is shown to improve the performance of high precision GNSS positioning for road vehicles, through the increased availability of GNSS correction messages and the rapid resolution of the N-RTK fixed solution. Positioning systems in the automotive sector are dominated by satellite-based solutions provided by GNSS. This has been the case since May 2001, when the United States Department of Defense switched off Selective Availability, enabling significantly improved positioning performance for civilian users. The average person most frequently encounters GNSS when using electronic personal navigation devices. The Sat Nav or GPS Navigator is ubiquitous in modern societies, where versions can be found on nomadic devices such as smartphones and dedicated personal navigation devices, or built in to the dashboards of vehicles. Such devices have been hugely successful due to their intrinsic ability to provide position information anywhere in the world with an accuracy of approximately 10 metres, which has proved ideal for general navigation applications. There are a few well known limitations of GNSS positioning, including anecdotal evidence of incorrect navigation advice for personal navigation devices, but these are minor compared to the overall positioning performance. Through steady development of GNSS positioning devices, including the integration of other low cost sensors (for instance, wheel speed or odometer sensors in vehicles), and the development of robust map matching algorithms, the performance of these devices for navigation applications is truly incredible. However, when tested for advanced automotive applications, the performance of GNSS positioning devices is found to be inadequate. In particular, in the most advanced fields of research such as autonomous vehicle technology, GNSS positioning devices are relegated to a secondary role, or often not used at all. They are replaced by terrestrial sensors that provide greater situational awareness, such as radar and lidar. This is due to the high performance demand of such applications, including high positioning accuracy (sub-decimetre), high availability and continuity of solutions (100%), and high integrity of the position information. Low-cost GNSS receivers generally do not meet such requirements. This could be considered an enormous oversight, as modern GNSS positioning technology and techniques have significantly improved satellite-based positioning performance. Other non-GNSS techniques also have their limitations that GNSS devices can minimise or eliminate. For instance, systems that rely on situational awareness require accurate digital maps of their surroundings as a reference. GNSS positioning can help to gather this data, provide an input, and act as a fail-safe in the event of digital map errors. It is apparent that in order to deliver advanced automotive applications - such as semi- or fully-autonomous vehicles - there must be an element of absolute positioning capability. Positioning systems will work alongside situational awareness systems to enable the autonomous vehicles to navigate through the real world. A strong candidate for the positioning system is GNSS positioning. This thesis builds on work already started by researchers at the University of Nottingham, to show that N-RTK positioning is one such technique. N-RTK can provide sub-decimetre accuracy absolute positioning solutions, with high availability, continuity, and integrity. A key component of N-RTK is the availability of real-time GNSS correction data. This is typically delivered to the GNSS receiver via mobile internet (for a roving receiver). This can be a significant limitation, as it relies on the performance of the mobile communications network, which can suffer from performance degradation during dynamic operation. Mobile communications systems are expected to improve significantly over the next few years, as consumers demand faster download speeds and wider availability. Mobile communications coverage already covers a high percentage of the population, but this does not translate into a high percentage of a country's geography. Pockets of poor coverage, often referred to as notspots, are widespread. Many of these notspots include the transportation infrastructure. The vehicle-to-vehicle concept has made significant forward steps in the last few years. Traditionally promoted as a key component of future automotive safety applications, it is now driven primarily by increased demand for in-vehicle infotainment. The concept, which shares similarities with the Internet of Things and Mobile Ad-hoc Networks, relies on communication between road vehicles and other road agents (such as pedestrians and road infrastructure). N-RTK positioning can take advantage of this communication link to minimise its own communications-related limitations. Sharing GNSS information between local GNSS receivers enables better performance of GNSS positioning, based on the principles of differential GNSS and N-RTK positioning techniques. This advanced concept is introduced and tested in this thesis. The Pseudo VRS concept follows the protocols and format of sharing GNSS data used in N-RTK positioning. The technique utilises the latest GNSS receiver design, including multiple frequency measurements and high quality antennas

Developing and Evaluating the driving and powertrain systems of automated and electrified vehicles (AEVs) for sustainable transport

In the transition towards sustainable transport, automated and electrified vehicles (AEVs) play a key role in overcoming challenges such as fuel consumption, emissions, safety, and congestion. The development and assessment of AEVs require bringing together insights from multiple disciplines such as vehicle studies to design and control AEVs and traffic flow studies to describe and evaluate their driving behaviours. This thesis, therefore, addresses the needs of automotive and civil engineers, and investigates three classes of problems: optimizing the driving and powertrain systems of AEVs, modelling their driving behaviours in microscopic traffic simulation, and evaluating their performance in real-world driving conditions. The first part of this thesis proposes Pareto-based multi-objective optimization (MOO) frameworks for the optimal sizing of powertrain components, e.g., battery and ultracapacitor, and for the integrated calibration of control systems including adaptive cruise control (ACC) and energy management strategy (EMS). We demonstrate that these frameworks can bring collective improvements in energy efficiency, greenhouse gas (GHG) emissions, ride comfort, safety, and cost-effectiveness. The second part of this thesis develops microscopic free-flow or car-following models for reproducing longitudinal driving behaviours of AEVs in traffic simulation, which can support the needs to predict the impact of AEVs on traffic flow and maximize their benefits to the road network. The proposed models can account for electrified vehicle dynamics, road geometric characteristics, and sensing/perception delay, which have significant effects on driving behaviours of AEVs but are largely ignored in traffic flow studies. Finally, we systematically evaluate the energy and safety performances of AEVs in real-world driving conditions. A series of vehicle platoon experiments are carried out on public roads and test tracks, to identify the difference in driving behaviours between ACC-equipped vehicles and human-driven vehicles (HDVs) and to examine the impact of ACC time-gap settings on energy consumption