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.

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.

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 no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/40370 / TESIS

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.

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.

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.

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.

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.

Yes / The Rician K-factor of the vehicle-to-vehicle (V2V) wireless propagation channel is estimated using a moment-based method on the envelope of measured pulse data. The measurements were carried out under vehicle-to-vehicle wireless communication channel condition with car rooftop antenna heights at one end of the link and very low antenna height at the other end. Data captured from typical urban, suburban and rural areas are analyzed and the K-factor probability density function is generated for each scenario to give an insight into the V2V channel behavior. For all three areas, the majority of K values are found to be within the range of -10 to +10 dB. The K-factor distributions are close to normal with mean values of 1.8, 2.6 and 3 dB respectively for urban, suburban and rural area.

No description available.