Neste trabalho, é desenvolvido um estudo sobre o uso de alertas auditivos e hápticos dentro do ambiente veicular. É proposto um sistema de assistência ao motorista para alertá-lo de que uma colisão lateral com outros veículos pode ser iminente, quando a observação do espelho retrovisor é insuficiente ou o motorista está desatento. O sistema é composto por um módulo de ativação e um módulo de alerta. O módulo de ativação detecta a condição de perigo por sensores posicionados ao redor do veículo e na tendência de abandono de faixa. Esse trabalho enfoca o módulo de alerta, para o qual se propõe o uso de som tridimensional juntamente com estímulo de vibração. Um ambiente de simulação é proposto para se reproduzir em laboratório o ambiente em que o motorista atua. Nesse ambiente, o sujeito deve utilizar um jogo de corrida projetado na parede à sua frente usando um volante e pedais para acelerar e frear. O motorista se mantém ocupado na tarefa de conduzir o veículo pela trajetória do jogo enquanto é submetido a situações em que um outro veículo se aproxima pela região lateral-traseira velozmente. O assento utilizado é equipado com os elementos geradores dos estímulos vibratórios e auditivos. No primeiro experimento, estuda-se o comportamento de 12 participantes na situação crítica sem o uso do sistema de alerta e conclui-se que a reação preferencial em tal situação é o esterçamento do volante. No segundo experimento, 23 participantes são submetidos ao mesmo cenário adicionando-se o sistema de alertas auditivo e háptico. São coletados os dados de tempo de reação, esterçamento do volante, pressionamento dos pedais e distância entre os carros. Também são registradas as percepções dos participantes sobre o sistema de alerta utilizado. A análise dos dados indica que o sistema de alerta é elegível para uso e pode auxiliar em termos de tempo de reação, devendo-se, entretanto, revisar as características dos alertas utilizados, especialmente o auditivo, para se reduzir o desconforto e evitar prejuízo significativo no controle do veículo. / In this work, we develop a study about the usage of auditive and haptic alerts in the vehicular environment. It is proposed a driver assistance system to warn the driver that a lateral collision with other vehicle may be imminent, when the rear mirror observation is insufficient or the driver is distracted. The system is composed by an activation module and a warning module. The activation module detects the dangerous condition using sensors placed around the vehicle and on the identification of a lane departure tendency. This work focuses on the warning module, which proposes the usage of three-dimensional sound together with vibration stimulus. A simulation environment is proposed to reproduce in laboratory the environment where the driver actuates. In this environment, the subject is requested to play a driving game projected in the frontal wall using a steering wheel and pedals to accelerate and brake. While the driver conducts the vehicle over the game route, he is submitted to the situation where another vehicle approaches very fastly from behind. The seat is equipped with the vibration and auditory stimuli generator elements. In the first experiment, it is assessed the behavior of 12 subjects in the critical situation without the usage of the warning system and it is concluded that the major reaction in such situation is the steering of the wheel. In the second experiment, 23 subjects are submitted to the same scenario adding the auditory and haptic warning system. The following data are collected: reaction time, wheel steering, pedal pressing and distance between the vehicles. The perception of the participants about the used warning system is registered. The analysis of all data indicates that the system is eligible to be used and is able to help regarding reaction times. Nevertheless, it is still necessary to review the characteristics of the used warnings, specially the auditory, to reduce discomfort and avoid loss of control during driving.

Cette thèse est consacrée à étudier les applications potentielles de véhicules autonomes et communications V2X pour construire les systèmes de transport intelligents. Premièrement, le comportement de caravane dans un environnement de véhicule connecté est étudié. Un algorithme de commande de caravane est conçu pour obtenir l'espacement sécuritaire ainsi que la conformité de la vitesse et de l'accélération. Deuxièmement, à plus grande échelle, les caravanes autour d'une intersection sont considérées. Le débit pendant une période de signal de trafic peut être amélioré en tirant profit de la capacité redondante de la route. Dans diverses contraintes, les véhicules peuvent choisir d'accélérer et rejoindre la caravane précédente ou à décélérer de déroger à l'actuel. Troisièmement, une intersection sans signalisation en VANET est considérée. Dans des conditions de faible trafic, les véhicules peuvent réguler leur vitesse avant d'arriver à l'intersection en fonction du temps d'occupation de la zone de conflit (TOZC) stocké au niveau du gestionnaire, afin qu'ils puissent traverser l'intersection sans collision ni arrêt. Le délai peut être réduit en conséquence. Enfin, un algorithme de gestion d'intersection autonome universelle, qui peut fonctionner même avec le trafic lourd, est développé. Le véhicule cherche à sécuriser les fenêtres entrant dans le TOZC. Ensuite, sur la base des fenêtres trouvées et le mouvement du véhicule qui précède, les trajectoires des véhicules peuvent être planifiées en utilisant une méthode de programmation dynamique segmentée. Tous les algorithmes conçus sont testés et vérifiés avec succès par des simulations dans scénarios différents / This thesis is devoted to study the potential applications of autonomous vehicles and V2X communications to construct the intelligent transportation systems. Firstly, the behavior of platoon in connected vehicle environment is studied. A platoon control algorithm is designed to obtain safe spacing as well as accordance of velocity and acceleration for vehicles in the same lane. Secondly, in larger scale, the platoons around an intersection are considered. The throughput in a traffic signal period can be improved by taking advantage of the redundant road capacity. Within diverse constraints, vehicles can choose to accelerate to join in the preceding platoon or to decelerate to depart from the current one. Thirdly, an unsignalized intersection in VANET is considered. In light traffic conditions, vehicles can regulate their velocities before arriving at the intersection according to the conflict zone occupancy time (CZOT) stored at the manager, so that they could get through the intersection without collision or stop. The delay can be reduced accordingly. Finally, an universal autonomous intersection management algorithm, which can work even with heavy traffic, is developed. The vehicle searches for safe entering windows in the CZOT. Then based on the found windows and the motion of preceding vehicle, the trajectories of vehicles can be planned using a segmented dynamic programming method. All the designed algorithms are successfully tested and verified by simulations in various scenarios

Abstract Although researchers have studied the effects of platooning, most of the work done so far has focused on fuel consumption. There are a few studies that have targeted the impact of platooning on the highway operations and safety. This thesis focuses on the impact of heavy-duty vehicles (HDVs) platooning on highway characteristics. Specifically, this study aims at evaluating the effects of platooning of HDVs on capacity, safety, and CO2 emissions. This study is based on a hypothetical model that was created using the VISSIM software. VISSIM is a powerful simulation software designed to mimic the field traffic flow conditions. For model validity, the model outputs were compared with recommended values from guidelines such as the Highway Capacity Manual (HCM) (Transportation Research Board, 2016). VISSIM was used to obtain the simulation results regarding capacity. However, in addition to VISSIM, two other software packages were used to obtain outputs that cannot be assessed in VISSIM. MOVES and SSAM are two simulation software packages that were used for emission and safety metrics, respectively. Both software packages depended on input from VISSIM for analysis. It was found that with the presence of HDVs in the model, the capacity, the emission of CO2, and the safety of the roadway would improve positively. A capacity of 4200 PCE/h/ln could be achieved when there are enough HDVs in platoons. Furthermore, more than 3% of the traffic flow emission of CO2 reduction is possible when 100% of the HDVs used in the model are in platoons. In addition to that, a reduction of more than 75% of the total number of conflicts might be obtained. Furthermore, with the analysis of the full factorial method and the Design of Experiment (DOE) conducted by using Excel and Minitab respectively, it was possible to investigate the impact of the platoons’ factors on the highway parameters. Most of these factors affect the parameters significantly. However, the change in the desired speed was found to insignificantly affect the highway parameters, due to the high penetration rate. Keywords: VISSIM, MOVES, SSAM, COM-interface, HDVs, Platooning, Number of Conflicts

Le protocole MAC du standard IEEE 802.11p dédié aux réseaux véhiculaires interdit les transmissions simultanées dans une même zone de détection afin d’éviter d’éventuelles interférences entre les véhicules voisins. Cette interdiction entraîne un blocage temporaire de réception de données, ce qui diminue le débit global du réseau. Pour résoudre ce problème, nous proposons dans cette thèse une architecture cross-layer PHY/MAC basée sur un algorithme de sélection d’antennes émettrices et un protocole MAC dédié afin de réduire le blocage. Ce cross-layer permet au récepteur de choisir la meilleure combinaison d’antennes émettrices pour améliorer le débit utile normalisé de chaque lien V2V. L’algorithme est présenté avec une méthode de détection multi-utilisateurs. Cette méthode annule les interférences entre voisins et permet à plusieurs véhicules d’émettre des données simultanément. Le protocole MAC associé assure la coordination entre les véhicules durant les communications. Les résultats de simulation montrent une amélioration du débit utile normalisé du réseau en comparaison au standard actuel. Néanmoins, ces bonnes performances diminuent avec l’augmentation de la densité véhiculaire. Pour pallier à cette baisse, nous proposons de joindre à la première solution une nouvelle architecture crosslayer PHY/MAC. Cette architecture est basée sur un algorithme d’adaptation de la puissance émise en fonction de la densité de voisinage du récepteur. Elle est également accompagnée par un protocole MAC dédié. Les résultats de simulation montrent que cette solution permet à plus de véhicules de communiquer simultanément et ainsi améliore significativement le débit utile normalisé notamment dans les réseaux véhiculaires denses. / The MAC protocol IEEE 802.11p, dedicated to vehicular ad-hoc networks VANETs, prohibits simultaneous transmissions in the same detection area, in order to avoid interference between neighboring vehicles. This prohibition causes a temporary data reception blocking, which reduces the network throughput. To reduce this adverse impact, we propose in this thesis a cross-layer design PHY/MAC based on a transmit antennas selection algorithm jointly with a dedicated MAC protocol. This design allows receivers to select the best combination of transmit antennas to improve the throughput of each V2V link. The algorithm is presented with a multi-user detection method, which cancels neighbor’s interference and allows vehicles to transmit data simultaneously. The associated MAC protocol ensures the coordination between vehicles during the simultaneous transmission period. The simulation results show a significant network throughput improvement compared to the conventional case. However, this improvement is less important in dense VANETs. For this purpose, we propose to join a cross-layer design PHY/MAC based on a transmit power adaptation algorithm. This design allows transmitters to choice the adequate power level based on corresponding receivers density. The simulation results show that this solution allows more vehicles to communicate simultaneously and thus improves the network throughput, in particular in dense VANETs.

Les réseaux véhiculaires sont des réseaux émergents qui permettent de connecter des véhicules entre eux et avec les infrastructures routières. Ils permettent de mettre en œuvre des applications de sécurité (évitement des collisions, prévention des travaux, etc.), des applications temps-réel (aide à la conduite automatisée), des applications des systèmes de transport intelligents (gestion du trafic, proposition de détours, etc.), des applications de confort (péage automatique des autoroutes, connexion à du contenu multimédia en ligne, etc.). Pour fonctionner pleinement, le véhicule a besoin d’une puissance de calcul de plus en plus grande et d’une connexion quasi-continue. Afin de garantir cette contrainte, les réseaux véhiculaires font de plus en plus appel au Cloud. Cette thèse vise à explorer les différentes interactions entre les réseaux véhiculaire et Cloud. / Vehicular Ad-hoc Networks (VANETs) are a new kind of networks which allow to connect vehicles between them and with the road infrastructures. It make possible to deploy safety applications (colision avoidance, roadworks advertisement, etc.), real time application (driver assistance, automated driving, etc.), comfort application (automatic toll payment, access to multimedia contents via internet, etc.). In order to be functioning completely, the vehicle needs more and more computing power and a connection with almost no interruption. To guarantee this constraints, VANETs are using more and more often the Cloud Computing. This thesis aims to explore the differents intereactions between VANETs and the Cloud

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<p>This licentiate thesis work investigates two medium access control (MAC) methods, when used in traffic safety applications over vehicular <em>ad hoc</em> networks (VANETs). The MAC methods are carrier sense multiple access (CSMA), as specified by the leading standard for VANETs IEEE 802.11p, and self-organizing time-division multiple access (STDMA) as used by the leading standard for transponders on ships. All vehicles in traffic safety applications periodically broadcast cooperative awareness messages (CAMs). The CAM based data traffic implies requirements on a predictable, fair and scalable medium access mechanism. The investigated performance measures are <em>channel access delay</em>, <em>number of consecutive packet drops</em> and the <em>distance between concurrently transmitting nodes</em>. Performance is evaluated by computer simulations of a highway scenario in which all vehicles broadcast CAMs with different update rates and packet lengths. The obtained results show that nodes in a CSMA system can experience <em>unbounded channel access delays</em> and further that there is a significant difference between the best case and worst case channel access delay that a node could experience. In addition, with CSMA there is a very high probability that several <em>concurrently transmitting nodes are located close to each other</em>. This occurs when nodes start their listening periods at the same time or when nodes choose the same backoff value, which results in nodes starting to transmit at the same time instant. The CSMA algorithm is therefore both <em>unpredictable</em> and <em>unfair</em> besides the fact that it <em>scales badly</em> for broadcasted CAMs. STDMA, on the other hand, will always grant channel access for all packets before a predetermined time, regardless of the number of competing nodes. Therefore, the STDMA algorithm is <em>predictable</em> and <em>fair</em>. STDMA, using parameter settings that have been adapted to the vehicular environment, is shown to outperform CSMA when considering the performance measure <em>distance between concurrently transmitting nodes</em>. In CSMA the distance between concurrent transmissions is random, whereas STDMA uses the side information from the CAMs to properly schedule concurrent transmissions in space. The price paid for the superior performance of STDMA is the required network synchronization through a global navigation satellite system, e.g., GPS. That aside since STDMA was shown to be scalable, predictable and fair; it is an excellent candidate for use in VANETs when complex communication requirements from traffic safety applications should be met.</p>

The super collision between the Internet phenomenon and the wireless communication revolution gives birth to a wealth of novel research problems, design challenges and standardization activities. Within this domain, spontaneous wireless IP networking are probably the most extreme example of new ''particles'' born from the collision. Indeed, these particles defy the laws of the Internet in many ways. The absorption of such peculiar particles in the global IP network has already started thanks to pioneering algorithmic and protocol work -- for instance OLSR -- and through the deployment of wireless mesh networks around the world, such as urban community wireless networks. With the recent revolutions in North Africa, and movements such as Occupy Wall Street, the prospect of spontaneous wireless IP networking has become even more attractive on social and political grounds. Dedicated conferences have recently been organized, and as a result, ambitious, multi-million dollar initiatives have been launched (e.g. the US Government-funded project Commotion Wireless, or the EU-funded initiative CONFINE). However, spontaneous IP wireless networks are not yet widely deployed because pioneer work such as OLSR is vastly insufficient to fully bridge the gap between the Internet and these new networks. This thesis presents work that analyzes this gap and proposes some solutions as to how to bridge it. The focus is put on three domains: a first part presents work in the domain of wireless mesh and ad hoc networks. A second part presents work on sensor networks and in the Internet of Things. And the last part presents work in the domain of delay tolerant networking and vehicular networks.

Advances in computing and wireless communication technologies have increased interest in smart vehicles, vehicles equipped with significant computing, communication and sensing capabilities to provide services to travelers. Smart vehicles can be exploited to improve driving safety and comfort as well as optimize surface transportation systems. Wireless communications among vehicles and between vehicles and roadside infrastructures represent an important class of vehicle communications. One can envision creating an integrated radio network leveraging various wireless technologies that work together in a seamless fashion. Based on cost-performance tradeoffs, different network configurations may be appropriate for different environments. An understanding of the properties of different vehicular network architectures is absolutely necessary before services can be successfully deployed. Based on this understanding, efficient data services (e.g., data dissemination services) can be designed to accommodate application requirements. This thesis examines several research topics concerning both the evaluation and design of vehicular networks. We explore the properties of vehicle-to-vehicle (v2v) communications. We study the spatial propagation of information along the road using v2v communications. Our analysis identifies the vehicle traffic characteristics that significantly affect information propagation. We also evaluate the feasibility of propagating information along a highway. Several design alternatives exist to build infrastructure-based vehicular networks. Their characteristics have been evaluated in a realistic vehicular environment. Based on these evaluations, we have developed some insights into the design of future broadband vehicular networks capable of adapting to varying vehicle traffic conditions. Based on the above analysis, opportunistic forwarding that exploit vehicle mobility to overcome vehicular network partitioning appears to be a viable approach for data dissemination using v2v communications for applications that can tolerate some data loss and delay. We introduce a methodology to design enhanced opportunistic forwarding algorithms. Practical algorithms derived from this methodology have exhibited different performance/overhead tradeoffs. An in-depth understanding of wireless communication performance in a vehicular environment is necessary to provide the groundwork for realizing reliable mobile communication services. We have conducted an extensive set of field experiments to uncover the performance of short-range communications between vehicles and between vehicles and roadside stations in a specific highway scenario.

Each day, Humanity loses thousands of persons on roads when they were traveling to work, to study or even to distract. The financial cost of these injuries is also terrifying: Some statistics evaluate the financial cost of vehicle accidents at 160 billion Euro in Europe each year. These alarming figures have driven researchers, automotive companies and public governments to improve the safety of our transportation systems and communication technologies aiming at offering safer roads and smooth driving to human beings. In this context, Vehicular Adhoc Networks, where vehicles are able to communicate with each others and with existent road side units, emerge as a promising wireless technology able to enhance the vision of drivers and offer larger telematic horizon. VANETs promising applications are not only restricted to road safety but span from vehicle trafficoptimization like flow congestion control to commercial applications like file sharing and internet access. Safety applications require that their alert information is propagated to the concerned vehicles (located in the hazardous zone) with little delay and high reliability. For these reasons, this category of applications is considered as delay sensitive and broadcast-oriented nature. While classical blind flooding is rapid, its major drawback is its huge bandwidth utilization. In this thesis, we are interested on enhancing vehicular communications under different scenarios and optimizations: First, We focus on deriving a new solution (EBDR) to disseminate alert messages among moving vehicles while maintaining it efficient and rapid. Our proposal is based on directional antennas to broadcast messages and a route guidance algorithm to choose the best path for the packets. Findings confirmed the efficiency of our approach in terms of probability of success and end-to-end delays. Moreover, in spite of the broadcast nature of the proposed technique, all transmissions stop very soon after the arrival of a packet to its destination representing a strong feature in the conception of EBDR. Second, we propose a novel mathematical framework to evaluate the performance of EBDR analytically. Although most of the proposed techniques present in literature use experimental or simulation tools to defend their performance, we rely here on mathematical models to confirm our achieved results. Our proposed framework allows to derive meaningful performance metrics including the probability of transmission success and the required number of hops to reach thefinal destination. Third, we refine our proposed broadcast-based routing EBDR to provide more efficient broadcasting by adjusting the transmission range of each vehicle based on its distance to the destination and the local node density. This mechanism allows better minimization of interferences and bandwidth's saving. Furthermore, an analytical model is derived to calculate thetransmission area in the case of a simplified node distribution. Finally, we are interested on data collection mechanisms as they make inter-vehicle communications more efficient and reliable and minimize the bandwidth utilization. Our technique uses Q-learning to collect data among moving vehicles in VANETs. The aim behind using the learning technique is to make the collecting operation more reactive to nodes mobility and topology changes. For the simulation part, we compare it to a non-learning version to study the effect of the learning technique. Findings show that our technique far outperforms other propositions and achieves a good trade off between delay and collection ratio. In conclusion, we believe that the different contributions presented in this Thesis will improve the efficiency of inter-vehicle communications in both dissemination and data collection directions. In addition, our mathematical contributions will enrich the literature in terms of constructing suitable models to evaluate broadcasting techniques in urban zones