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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Utveckling och mätning av följdetekteringsalgoritm för V2V med hänsyn till tidsfördröjning / Development and measurement of a followdetection algorithm for V2V with regards to time delay

Rahme, Daniel January 2017 (has links)
Trafikolyckor är ett problem i dagens samhälle och nya lösningar inom intelligenta transportsystem (ITS) efterfrågas. En lösning är fordon-till-fordon kommunikation (V2V), där säkrare trafik kan uppnås genom att fordon sänder relevant trafikdata till omgivande trafik. I denna rapport undersöktes och utvecklades metoder för en följdetekteringsalgoritm inom V2V kommunikation. Uppdraget var att hitta en lösning för följdetektering med GPS och radiokommunikation med FM-RDS, där hänsyn togs till tidsfördröjning. Algoritmer utvecklades i en simuleringsmiljö, för att sedan implementeras i en egenkonstruerad prototyp för mätning i trafik. För effektivt utnyttjande av FM-RDS-paket komprimerades den sända positionen, för att sedan rekonstrueras vid mottagarsidan.Resultaten av simuleringarna och trafikmätningarna visade att det var möjligt att detektera om ett fordon följde efter ett annat i trafiken, med hjälp av GPS-positionering och kommunikation genom FM-RDS med tidsfördröjning av mottagna paket. Vid högre tidsfördröjningar så presterade algoritmen sämre, dock finns det potential till förbättring. Förslag på förbättring av rekonstruktionsfunktionen samt algoritmen behandlas i denna rapport. / Traffic accidents are a problem in today’s society and new solutions regarding intelligent transportation systems (ITS) are being requested. One solution to such is vehicle-to-vehicle communication (V2V), where safer traffic can be achieved by vehicles transmitting relevant traffic information to surrounding vehicles. In this report, we researched and developed methods for a follow-detection algorithm for V2V communication. The task was to find a solution for follow-detection by using GPS and FM-RDS, with regards to time delay. An algorithm was developed in a simulated environment, to then be implemented in a prototype for measuring traffic. For efficient usage of FM-RDS packets, the transmitted position was compressed and then decompressed at the receiving side. The results of the simulations and traffic tests indicated that it was possible to detect if a vehicle followed another in traffic, by using GPS positioning and FM-RDS with time delay. The accuracy of the algorithm degraded at higher time delays, however there is potential for improvements. Suggestions for improvements of the reconstruction function and the algorithm are discussed in this report.
12

Vehicle to Vehicle Communication in Level 4 Autonomy

Hajimirsadeghi, Seyedsalar 01 January 2017 (has links)
With the number of deaths, commute time, and injuries constantly rising due to human driving errors, it’s time for a new transportation system, where humans are no longer involved in driving decisions and vehicles are the only machine that decide the actions of a vehicle. To accomplish a fully autonomous world, it’s important for vehicles to be able to communicate instantly and report their movements in order to reduce accidents. This paper discusses four approaches to vehicle to vehicle communication, as well as the underlying standards and technology that enable vehicles to accomplish communicating.
13

Emulace infrastrukturní jednotky pro systém inteligentní dopravy / Emulation of infrastructure unit for inteligent transport system

Giertl, Juraj January 2018 (has links)
The thesis deals with the study of communication models for cooperative intelligent transport systems and the development of the application used for testing. The ETSI ITS-G5 and IEEE 1609.x DSRC/WAVE comunication stacks were compared to standartizes layered ISO/OSI reference model. The basic principes of comunication in inteligent transport systems are described for each model. Besides that the common messages structures for defining alert messages, the intersection geometry and trafic lights signals are described in further detail. Based on these structures and other requirements, an application is created that allows easy definition of alert messages, intersection geometry and its traffic light states.
14

Návrh komunikace mezi pohybujícími se vozidly / Design of Communication system among Moving Vehicles

Klampár, Marián January 2010 (has links)
The purpose of this thesis is to show up possibilities of inter-vehicle communication and to introduce new approaches in communication for the purpose of enhancing the security and the fluency of vehicle transportation. This thesis also highlights vulnerabilities in communication. The main goal is the analysis of existing technology and the design of protocol for data transfer with focus on minimizing handover time of informations. Part of the design is a simulation of communication based on acquired information.
15

Intersection coordination for Autonomous Vehicles

Alhuttaitawi, Saif January 2019 (has links)
Connected Autonomous Vehicles require intelligent autonomous intersection management for safe and efficient operation. Given the uncertainty in vehicle trajectory, intersection management techniques must consider a safety buffer among the vehicles, which must also account for the network and computational delay, queue and determine the best solution to avoid traffic congestions (smart intersection management), in this paper we model traffic by using Poisson distribution method then add a birth-death processes for each state and combine both two in one queuing system (The Markovian chain) to model the traffic.Also, this paper will compare some autonomous vehicles communication techniques in intersections to draw the best scenario for autonomous vehicle network communication in order to reduce the traffic congestion in an intersection.The Connected Autonomous Vehicles and a normal autonomous vehicle, as well from the third line of the intersection a mix between the both will be provided into the intersection.The last section is about applying the results from the first and second research question into a simulator and compare the simulation results to approve the advantage of using the next generation of transportation technology (The connected autonomous vehicles) over the normal conventional vehicles.
16

Manoeuvre Coordination : Assuring safety in overtaking

Sakhnini, Qusay, Suleiman, Mohammad January 2023 (has links)
The frightful statistics regarding road accidents draws a dreadful picture for individuals, communities, and nations across the globe. The number of fatalities exceeds a million every year. To address this issue, an initiative called Vision Zero was introduced first in Sweden 1997. The goal is to reach zero road fatalities and severe injuries by 2045. However, to achieve this goal, Vision Zero is being divided in 4 categories, called Days. Day 4 represents fully automated, cooperative, and connected mobility (CCAM). Now, one of the typical cases that causes road accidents is overtaking. CCAM is a way to enhance safety in such cases. Therefore, this thesis proposes a system that is based on Vehicle-to-Vehicle (V2V) communication where vehicles exchange their intentions and cooperatively perform overtaking manoeuvres. The prevalent approach nowadays is depending on the vehicles’ onboard sensors only, blocking it from having knowledge about the intentions of other actors. Thus, it prevents vehicles from cooperation and coordination. We evaluate the performance of our approach and compare it against the sensors only approach. We show that the proposed approach outperforms the prevalent one in performance. Therefore, vehicle communication must be considered in the upcoming mobility for higher accuracy and safety. / Den skrämmande statistiken angående trafikolyckor tecknar en fruktansvärd bild för individer, samhällen och nationer över världen. Antalet dödsfall överstiger en miljon varje år. Ett initiativ som kallas Vision Zero introducerades i Sverige 1997, vars syfte är att ta itu med detta problem. Målet är att nå noll trafik dödsfall, och allvarliga skador år 2045. För att verkställa det målet, Vision Zero delades in i 4 kategorier, som kallas för Dagar. Dag 4 representerar fullt automatiserad, kooperativ och kommunikativ mobilitet (CCAM). Ett av det vanligaste fallen som orsaker trafikolyckor är omkörningar. CCAM är ett sätt att förbättra säkerheten i sådana fall. Därför presenterar denna avhandling ett system som bygger på fordon-till-fordon (Vehicle-to-Vehicle V2V) kommunikation. Detta system tillåter fordon att utbyta avsikter för att samarbeta och utföra säkra omkörningar. Den ledande teknologin nuförtiden beror enbart av fordonens sensorer, vilket hindrar dem från att ha kunskap om andra aktörers avsikter. Därmed hindrar det dem från att samarbeta. Vi utvärderar prestandan av vårt system och jämför det med den ledande teknologin. Vi visar att vårt system är överlägsen det ledande sättet (dvs. enbart sensorer) i prestanda. Därför måste fordon kommunikation tas hänsyn till i kommande mobilitet för högre noggrannhet och säkerhet.
17

Assessment of Vehicle-to-Vehicle Communication based Applications in an Urban Network

Kim, Taehyoung 23 June 2015 (has links)
Connected Vehicle research has emerged as one of the highest priorities in the transportation systems because connected vehicle technology has the potential to improve safety, mobility, and environment for the current transportation systems. Various connected vehicle based applications have been identified and evaluated through various measurements to assess the performance of connected vehicle applications. However, most of these previous studies have used hypothetical study areas with simple networks for connected vehicle environment. This study represents connected vehicle environment in TRANSIMS to assess the performance of V2V communication applications in the realistic urban network. The communication duration rate and spatial-temporal dispersion of equipped vehicles are investigated to evaluate the capability of V2V communication based on the market penetration rate of equipped vehicles and wireless communication coverage in the whole study area. The area coverage level is used to assess the spatial-temporal dispersion of equipped vehicles for two study areas. The distance of incident information propagation and speed estimation error are used to measure the performance of event-driven and periodic applications based on different market penetration rates of equipped vehicles and wireless communication coverage in both morning peak and non-peak times. The wireless communication coverage is the major factor for event-driven application and the market penetration rate of equipped vehicles has more impact on the performance of periodic application. The required minimum levels of deployment for each application are determined for each scenario. These study findings will be useful for making decisions about investments on deployment of connected vehicle applications to improve the current transportation systems. Notably, event-driven applications can be reliably deployed in the initial stage of deployment despite the low level of market penetration of equipped vehicles. / Ph. D.
18

CROSS-LAYER DESIGN FOR LOCATION- AND DELAY-AWARE COMMUNICATION IN VEHICULAR NETWORKS

Jarupan, Boangoat 25 July 2011 (has links)
No description available.
19

Cooperative Clothoidal-Estimation Based Lane Detection For Vehicle Platooning

Hunde, Sena Aschalew 09 June 2021 (has links)
Vehicle platooning is an advanced vehicle maneuver that allows for the simultaneous control of several vehicles traveling on the roadway cite{al2010experimental}. Automated platoons, when activated in tractor trailer convoys, have a high potential of increasing the fuel efficiency and improving the utilization of roadways by allowing more vehicles to share the road at the same time. The increased fuel efficiency translates to lower cost on goods and motivates a more environmentally friendly and sustainable economy. In order to achieve the promised fuel savings from vehicle platooning, the vehicles need to follow each other at shorter headways than in typical driving scenarios. The reduced separation distance between the lead and follow vehicle reduces visibility and the reaction time available for the follow vehicle; this renders most modern Active Driver Assist Systems (ADAS) ineffective since they are not designed for operation in such short headway conditions. The focus of this work is related to understanding and improving the failures of Lane Keep Assist (LKA) systems in the follow vehicles of a platoon. In this work, the source of lane detection degradation when using a monocular forward facing camera in short headway platooning is identified. Furthermore, a novel lane augmentation algorithm is proposed to improve the lane detection capability of follow vehicles in a platoon. The lane augmentation process utilizes a longitudinal transformation of lane parameters from the lead to the follow vehicles. The transformation utilizes an accurate understanding of the relative spatial position and orientation of the two vehicles. The transformation also requires a reliable communication system between the two vehicles such as a Vehicle-to-Vehicle (V2V) module. The work presented in this thesis develops theory, simulation and verification using real world data of the proposed cooperative lane augmentation. The results of this work indicate that it is possible to improve vehicle platooning performance by distributing the required sensing across multiple agents of the platoon. / Master of Science / Vehicle platooning is an advanced vehicle maneuver that allows for the simultaneous control of several vehicles traveling on the roadway cite{al2010experimental}. Automated platoons, when activated in tractor trailer convoys, have a high potential of increasing the fuel efficiency and improving the utilization of our roadways by allowing more vehicles to share the road at the same time. The increased fuel efficiency translates to lower cost on goods and motivates a more environmentally friendly and sustainable economy. In order to achieve the promised fuel savings from vehicle platooning, the vehicles need to follow each other at closer distances (headway) than in typical driving scenarios. The reduced separation distance between the lead and follow vehicle reduces visibility and the reaction time available for the follow vehicle; this renders most modern Active Driver Assist Systems (ADAS) ineffective since they are not designed for operation in such short headway conditions. The focus of this work is related to understanding and improving the failures of Lane Keep Assist (LKA) systems - the automated system used to keep the vehicle in the center of the lane - in the follow vehicles of a platoon. In the proposed scenario, the LKA uses a single forward facing camera to detect the lane lines ahead of the vehicle. The detected lanes serve as inputs to the lateral position (steering) controller in order to keep the vehicle in the center of the lane. In this work, the source of lane detection degradation in a follow vehicle of a short headway platoon is identified. Furthermore, a novel cooperative lane detection algorithm is proposed to improve the lane detection capability of the follow vehicles. The proposed algorithm utilizes lane information transformed from the lead to follow vehicle frame. The transformation utilizes the relative spatial position and orientation of the two vehicles. Additionally, a reliable communication protocol between the vehicles is required to transport the lane information. The work presented in this thesis develops theory, simulation and verification using real world data of the proposed algorithm. The results of this work indicate that lane keeping performance in a platoon can be improved using cooperative lane detection.
20

Caracterización experimental de las pérdidas de propagación en comunicaciones vehiculares a 700 MHz y 5,9 GHz

Fernández González, Herman Antonio 29 September 2014 (has links)
En esta Tesis Doctoral se realiza una caracterización experimental de las pérdidas de propagación del canal radio vehicular basada en una extensa campaña de medidas realizada en diferentes escenarios de propagación, todos ellos potenciales entornos de comunicaciones vehiculares. Se han realizado medidas en escenarios urbanos, suburbanos, rurales y de autovía, con condiciones reales de tráfico rodado, diferentes densidades de vehículos y condiciones de propagación. La sonda de canal empleada en las medidas ha sido diseñada e implementada con el propósito de realizar una caracterización en banda estrecha permitiendo analizar el efecto de las pérdidas de propagación y desvanecimiento multicamino. Las medidas se han realizado en la banda DSRC (Dedicated Short-Range Communications) a 5,9 GHz, adoptada en EEUU y Europa para comunicaciones vehiculares, y en la banda de 700 MHz propuesta por Japón para este tipo de comunicaciones. En este sentido, los resultados mostrados en esta Tesis Doctoral a 700 MHz son los primeros realizados en esta banda de frecuencia. Se han propuesto diferentes métodos de análisis de las medidas realizadas, permitiendo un extenso estudio de los parámetros que caracterizan las pérdidas de propagación. Se ha analizado el canal radio vehículo a vehículo (V2V, Vehicular-to-Vehicular) y el canal vehículo a infraestructura (V2I, Vehicular-to-Infrastructure), estableciendo un modelo lineal entre las pérdidas de propagación y el logaritmo de la distancia entre el transmisor y receptor. Se trata de un modelo sencillo, pero bastante exacto, que permite una fácil implementación en simuladores de redes vehiculares. A diferencia de otros trabajos previos, que solamente analizan valores medios de los parámetros del modelo de pérdidas, en esta tesis se presentan resultados que permiten conocer el rango de variación de dichos parámetros En la investigación realizada se ha analizado el impacto que las condiciones de propagación, en lo que respecta a línea de visión directa y obstrucción de la misma, tienen sobre el comportamiento de la atenuación introducida por el canal radio. Los resultados derivados de esta Tesis Doctoral pueden ser utilizados el diseño y evaluación de protocolos de comunicación bajo condiciones de propagación próximas a la realidad, así como en el diseño y planificación de las futuras redes vehiculares. / Fernández González, HA. (2014). Caracterización experimental de las pérdidas de propagación en comunicaciones vehiculares a 700 MHz y 5,9 GHz [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/40370

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