151 research outputs found
Roadside LiDAR Assisted Cooperative Localization for Connected Autonomous Vehicles
Advancements in LiDAR technology have led to more cost-effective production
while simultaneously improving precision and resolution. As a result, LiDAR has
become integral to vehicle localization, achieving centimeter-level accuracy
through techniques like Normal Distributions Transform (NDT) and other advanced
3D registration algorithms. Nonetheless, these approaches are reliant on
high-definition 3D point cloud maps, the creation of which involves significant
expenditure. When such maps are unavailable or lack sufficient features for 3D
registration algorithms, localization accuracy diminishes, posing a risk to
road safety. To address this, we proposed to use LiDAR-equipped roadside unit
and Vehicle-to-Infrastructure (V2I) communication to accurately estimate the
connected autonomous vehicle's position and help the vehicle when its
self-localization is not accurate enough. Our simulation results indicate that
this method outperforms traditional NDT scan matching-based approaches in terms
of localization accuracy.Comment: Accepted by 2023 International Conference on Intelligent Computing
and its Emerging Application
A survey on pseudonym changing strategies for Vehicular Ad-Hoc Networks
The initial phase of the deployment of Vehicular Ad-Hoc Networks (VANETs) has
begun and many research challenges still need to be addressed. Location privacy
continues to be in the top of these challenges. Indeed, both of academia and
industry agreed to apply the pseudonym changing approach as a solution to
protect the location privacy of VANETs'users. However, due to the pseudonyms
linking attack, a simple changing of pseudonym shown to be inefficient to
provide the required protection. For this reason, many pseudonym changing
strategies have been suggested to provide an effective pseudonym changing.
Unfortunately, the development of an effective pseudonym changing strategy for
VANETs is still an open issue. In this paper, we present a comprehensive survey
and classification of pseudonym changing strategies. We then discuss and
compare them with respect to some relevant criteria. Finally, we highlight some
current researches, and open issues and give some future directions
Optimization of vehicular networks in smart cities: from agile optimization to learnheuristics and simheuristics
Vehicular ad hoc networks (VANETs) are a fundamental component of intelligent transportation systems in smart cities. With the support of open and real-time data, these networks of inter-connected vehicles constitute an âInternet of vehiclesâ with the potential to significantly enhance citizensâ mobility and last-mile delivery in urban, peri-urban, and metropolitan areas. However, the proper coordination and logistics of VANETs raise a number of optimization challenges that need to be solved. After reviewing the state of the art on the concepts of VANET optimization and open data in smart cities, this paper discusses some of the most relevant optimization challenges in this area. Since most of the optimization problems are related to the need for real-time solutions or to the consideration of uncertainty and dynamic environments, the paper also discusses how some VANET challenges can be addressed with the use of agile optimization algorithms and the combination of metaheuristics with simulation and machine learning methods. The paper also offers a numerical analysis that measures the impact of using these optimization techniques in some related problems. Our numerical analysis, based on real data from Open Data Barcelona, demonstrates that the constructive heuristic outperforms the random scenario in the CDP combined with vehicular networks, resulting in maximizing the minimum distance between facilities while meeting capacity requirements with the fewest facilities.Peer ReviewedPostprint (published version
Routing Unmanned Vehicles in GPS-Denied Environments
Most of the routing algorithms for unmanned vehicles, that arise in data
gathering and monitoring applications in the literature, rely on the Global
Positioning System (GPS) information for localization. However, disruption of
GPS signals either intentionally or unintentionally could potentially render
these algorithms not applicable. In this article, we present a novel method to
address this difficulty by combining methods from cooperative localization and
routing. In particular, the article formulates a fundamental combinatorial
optimization problem to plan routes for an unmanned vehicle in a GPS-restricted
environment while enabling localization for the vehicle. We also develop
algorithms to compute optimal paths for the vehicle using the proposed
formulation. Extensive simulation results are also presented to corroborate the
effectiveness and performance of the proposed formulation and algorithms.Comment: Publised in International Conference on Umanned Aerial System
From MANET to people-centric networking: Milestones and open research challenges
In this paper, we discuss the state of the art of (mobile) multi-hop ad hoc networking with the aim to present the current status of the research activities and identify the consolidated research areas, with limited research opportunities, and the hot and emerging research areas for which further research is required. We start by briefly discussing the MANET paradigm, and why the research on MANET protocols is now a cold research topic. Then we analyze the active research areas. Specifically, after discussing the wireless-network technologies, we analyze four successful ad hoc networking paradigms, mesh networks, opportunistic networks, vehicular networks, and sensor networks that emerged from the MANET world. We also present an emerging research direction in the multi-hop ad hoc networking field: people centric networking, triggered by the increasing penetration of the smartphones in everyday life, which is generating a people-centric revolution in computing and communications
Natural computing for vehicular networks
La presente tesis aborda el diseño inteligente de soluciones para el despliegue de redes vehiculares ad-hoc (vehicular ad hoc networks, VANETs). Estas son redes de comunicaciĂłn inalĂĄmbrica formada principalmente por vehĂculos y elementos de infraestructura vial. Las VANETs ofrecen la oportunidad para desarrollar aplicaciones revolucionarias en el ĂĄmbito de la seguridad y eficiencia vial. Al ser un dominio tan novedoso, existe una serie de cuestiones abiertas, como el diseño de la infraestructura de estaciones base necesaria y el encaminamiento (routing) y difusiĂłn (broadcasting) de paquetes de datos, que todavĂa no han podido resolverse empleando estrategias clĂĄsicas. Es por tanto necesario crear y estudiar nuevas tĂ©cnicas que permitan de forma eficiente, eficaz, robusta y flexible resolver dichos problemas.
Este trabajo de tesis doctoral propone el uso de computaciĂłn inspirada en la naturaleza o ComputaciĂłn Natural (CN) para tratar algunos de los problemas mĂĄs importantes en el ĂĄmbito de las VANETs, porque representan una serie de algoritmos versĂĄtiles, flexibles y eficientes para resolver problemas complejos. AdemĂĄs de resolver los problemas VANET en los que nos enfocamos, se han realizado avances en el uso de estas tĂ©cnicas para que traten estos problemas de forma mĂĄs eficiente y eficaz. Por Ășltimo, se han llevado a cabo pruebas reales de concepto empleando vehĂculos y dispositivos de comunicaciĂłn reales en la ciudad de MĂĄlaga (España).
La tesis se ha estructurado en cuatro grandes fases. En la primera fase, se han estudiado los principales fundamentos en los que se basa esta tesis. Para ello se hizo un estudio exhaustivo sobre las tecnologĂas que emplean las redes vehiculares, para asĂ, identificar sus principales debilidades. A su vez, se ha profundizado en el anĂĄlisis de la CN como herramienta eficiente para resolver problemas de optimizaciĂłn complejos, y de cĂłmo utilizarla en la resoluciĂłn de los problemas en VANETs. En la segunda fase, se han abordado cuatro problemas de optimizaciĂłn en redes vehiculares: la transferencia de archivos, el encaminamiento (routing) de paquetes, la difusiĂłn (broadcasting) de mensajes y el diseño de la infraestructura de estaciones base necesaria para desplegar redes vehiculares. Para la resoluciĂłn de dichos problemas se han propuesto diferentes algoritmos CN que se clasifican en algoritmos evolutivos (evolutionary algorithms, EAs), mĂ©todos de inteligencia de enjambre (swarm intelligence, SI) y enfriamiento simulado (simulated annealing, SA). Los resultados obtenidos han proporcionado protocolos de han mejorado de forma significativa las comunicaciones en VANETs. En la tercera y Ășltima fase, se han realizado experimentos empleando vehĂculos reales circulando por las carreteras de MĂĄlaga y que se comunicaban entre sĂ. El principal objetivo de estas pruebas ha sido el validar las mejoras que presentan los protocolos que se han optimizado empleando CN. Los resultados obtenidos de las fases segunda y tercera confirman la hipĂłtesis de trabajo, que la CN es una herramienta eficiente para tratar el diseño inteligente en redes vehiculares
Reliable Message Dissemination in Mobile Vehicular Networks
Les rĂ©seaux vĂ©hiculaires accueillent une multitude dâapplications dâinfo-divertissement et de sĂ©curitĂ©. Les applications de sĂ©curitĂ© visent Ă amĂ©liorer la sĂ©curitĂ© sur les routes (Ă©viter les accidents), tandis que les applications dâinfo-divertissement visent Ă amĂ©liorer l'expĂ©rience des passagers. Les applications de sĂ©curitĂ© ont des exigences rigides en termes de dĂ©lais et de fiabilitĂ© ; en effet, la diffusion des messages dâurgence (envoyĂ©s par un vĂ©hicule/Ă©metteur) devrait ĂȘtre fiable et rapide. Notons que, pour diffuser des informations sur une zone de taille plus grande que celle couverte par la portĂ©e de transmission dâun Ă©metteur, il est nĂ©cessaire dâutiliser un mĂ©canisme de transmission multi-sauts. De nombreuses approches ont Ă©tĂ© proposĂ©es pour assurer la fiabilitĂ© et le dĂ©lai des dites applications. Toutefois, ces mĂ©thodes prĂ©sentent plusieurs lacunes.
Cette thĂšse, nous proposons trois contributions. La premiĂšre contribution aborde la question de la diffusion fiable des messages dâurgence. A cet Ă©gard, un nouveau schĂ©ma, appelĂ© REMD, a Ă©tĂ© proposĂ©. Ce schĂ©ma utilise la rĂ©pĂ©tition de message pour offrir une fiabilitĂ© garantie, Ă chaque saut, tout en assurant un court dĂ©lai. REMD calcule un nombre optimal de rĂ©pĂ©titions en se basant sur lâestimation de la qualitĂ© de rĂ©ception de lien dans plusieurs locations (appelĂ©es cellules) Ă lâintĂ©rieur de la zone couverte par la portĂ©e de transmission de lâĂ©metteur. REMD suppose que les qualitĂ©s de rĂ©ception de lien des cellules adjacentes sont indĂ©pendantes. Il sĂ©lectionne, Ă©galement, un nombre de vĂ©hicules, appelĂ©s relais, qui coopĂšrent dans le contexte de la rĂ©pĂ©tition du message dâurgence pour assurer la fiabilitĂ© en multi-sauts. La deuxiĂšme contribution, appelĂ©e BCRB, vise Ă amĂ©liorer REMD ; elle suppose que les qualitĂ©s de rĂ©ception de lien des cellules adjacentes sont dĂ©pendantes ce qui est, gĂ©nĂ©ralement, plus rĂ©aliste. BCRB utilise les rĂ©seaux BayĂ©siens pour modĂ©liser les dĂ©pendances en vue dâestimer la qualitĂ© du lien de rĂ©ception avec une meilleure prĂ©cision. La troisiĂšme contribution, appelĂ©e RICS, offre un accĂšs fiable Ă Internet. RICS propose un modĂšle dâoptimisation, avec une rĂ©solution exacte optimale Ă l'aide dâune technique de rĂ©duction de la dimension spatiale, pour le dĂ©ploiement des passerelles. Chaque passerelle utilise BCRB pour Ă©tablir une communication fiable avec les vĂ©hicules.Vehicular networks aim to enable a plethora of safety and infotainment applications. Safety applications aim to preserve people's lives (e.g., by helping in avoiding crashes) while infotainment applications focus on enhancing the passengersâ experience. These applications, especially safety applications, have stringent requirements in terms of reliability and delay; indeed, dissemination of an emergency message (e.g., by a vehicle/sender involved in a crash) should be reliable while satisfying short delay requirements. Note, that multi-hop dissemination is needed to reach all vehicles, in the target area, that may be outside the transmission range of the sender. Several schemes have been proposed to provide reliability and short delay for vehicular applications. However, these schemes have several limitations. Thus, the design of new solutions, to meet the requirement of vehicular applications in terms of reliability while keeping low end-to-end delay, is required.
In this thesis, we propose three schemes. The first scheme is a multi-hop reliable emergency message dissemination scheme, called REMD, which guarantees a predefined reliability , using message repetitions/retransmissions, while satisfying short delay requirements. It computes an optimal number of repetitions based on the estimation of link reception quality at different locations (called cells) in the transmission range of the sender; REMD assumes that link reception qualities of adjacent cells are independent. It also adequately selects a number of vehicles, called forwarders, that cooperate in repeating the emergency message with the objective to satisfy multi-hop reliability requirements. The second scheme, called BCRB, overcomes the shortcoming of REMD by assuming that link reception qualities of adjacent cells are dependent which is more realistic in real-life scenarios. BCRB makes use of Bayesian networks to model these dependencies; this allows for more accurate estimation of link reception qualities leading to better performance of BCRB. The third scheme, called RICS, provides internet access to vehicles by establishing multi-hop reliable paths to gateways. In RICS, the gateway placement is modeled as a k-center optimisation problem. A space dimension reduction technique is used to solve the problem in exact time. Each gateway makes use of BCRB to establish reliable communication paths to vehicles
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Information collection algorithm for vehicular ad-hoc networks (application domain: Urban Traffic Wireless Vehicular Ad-Hoc Networks (VANETs))
Vehicle to vehicle communication (V2VC) is one of the modern approaches for exchanging and generating traffic information with (yet to be realized) potential to improve road safety, driving comfort and traffic control. In this research, we present a novel algorithm which is based on V2V communication, uses in-vehicle sensor information and in collaboration with the other vehicles' sensor information can detect road conditions and determine the geographical area where this road condition exists â e.g. geographical area where there is traffic density, unusual traffic behaviour, a range of weather conditions (raining), etc. The algorithms' built-in automatic geographical restriction of the data collection, aggregation and dissemination mechanisms allows warning messages to be received by any car, not necessarily sharing the identified road condition, which may then be used to identify the optimum route taken by the vehicle e.g. avoid bottlenecks or dangerous areas including accidents or congestions on their current routes. This research covers the middle ground between MANET [1] and collaborative data generation based on knowledge granularity (aggregation). It investigates the possibility of designing, implementing and modelling of the functionality of an algorithm (as part of the design of an intelligent node in an Intelligent Transportation System - ITS) that ensures active participation in the formation, routing and general network support of MANETs and also helps in-car traffic information and real-time control generation and distribution. The work is natural extension of the efforts of several large EU projects like DRIVE [2], GST [3] and SAFESPOT [4]
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