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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

Technologies and Evaluation Metrics for On-Board Over the Air Control

Datta, Aneysha January 2022 (has links)
This project has been carried out at the Electronic Embedded Systems Architecture Department at Volvo Construction Equipment (VCE), Eskilstuna, Sweden. It forms the baseline for a stepwise systematic research initiative to convert wired technologies used for certain in-vehicle control and communication components to wireless technologies. In-vehicle wireless networks are being increasingly improvised and researched to minimize the manufacturing and maintenance cost of the total amount of wiring harnesses within the vehicles. Fault tracking and maintenance becomes convenient within a wireless network. Wireless intra-vehicular communication provides an open architecture that can accommodate new components and applications. One such usability has been studied in this thesis for the Display Control Unit of Volvo paver machines. A newly designed hardware demands new technologies to ensure operator safety, security, comfort, convenience, and information. The research conducted in this thesis takes into account five probable use-cases in terms of control and communication around the new hardware, and studies suitable wireless technologies that could replace the wired technology that will be used. From a detailed literature study and the specifications provided by VCE, WAVE/IEEE802.11p and DMG/IEEE 802.11ad have been selected as optimal candidates. These two have been modelled at the physical layer of the system. After comparing the results of WAVE for 4 different channel models and 8 different coding and modulation schemes, it has been found that 1/2BPSK(3 Mbps) and 1/2 QPSK(6 Mbps) are optimal for the 3 Rician Fading Channels of Rural LOS, Urban LOS, and Highway LOS. For use-cases that involve larger distances and a large exchange of control signals, WAVE is a good choice. DMG has 19 modulation schemes for Single Carrier Modes and some of them are extremely robust at low SNR. Around SNR 20, it shows lesser packet errors than WAVE. The lower error rate is also evident from the BER values. For use-cases that involve smaller distances and a lot of image data, DMG is preferable. The work, however, does not study the safety and security aspects. Thean alysis and modelling are theoretical being based on literature studies and the necessary parameters provided by VCE. The model needs to be evaluated against field studies and practical measurements with a prototype before implementation inside the paver.
12

A Vehicular Ad Hoc Network Based Localization for a City Bus / En Fordons Ad Hoc Nätverksbaserad Lokalisering för en Stadsbuss

Shenoy, Prithvi January 2019 (has links)
City busses are operated on roads where the GPS signal is weak, because of the tall buildings surrounding these roads. The localization of city busses, needs to therefore rely on alternate technique in order to improve the accuracy. Recent standardization of inter vehicular communication has made this a readily available tool which can be used for localization. This thesis presents an approach towards localization of a city bus by means of vehicular ad hoc network. The two main components of localization by this approach is the initialization of location estimate component, and the real time location estimation component. In particular, the thesis develops the use of minimum mean square estimation for initialization and an extended Kalman filtering approach for real time location estimation. The localization method is mathematically described, considering the operating scenarios of a city bus. The accuracy of the proposed method is mathematically evaluated. The developed localization method is implemented in a simulation tool kit for inter vehicular communication. Simulation experiments were performed for operating scenarios of city bus. The result of initialization by minimum mean square error is compared to that of initialization by GPS, in-terms of localization accuracy. Different setups of road side units are compared in-terms of accuracy and update interval. The results show that the proposed method is feasible for localization of a city bus. This thesis was carried out in association with Scania AB, Södertälje. / Stadsbussar åker på vägar som är omgivna av byggnader, vilket försämrar stadsbussarnas GPSmottagning. Lokaliseringen av stadsbussar måste därför förlita sig på alternativ teknik för att förbättra noggrannheten. Nyligen standardiserad kommunikation mellan fordon har blivit till ett lättillgängligt verktyg som kan användas för lokalisering. Den här uppsatsen presenterar en strategi för lokalisering av en stadsbuss med hjälp av fordonets ad hoc-nätverk. Huvudkomponenterna för lokalisering är en initialiseringskomponent och realtidslägesuppskattningskomponent. Speciellt utvecklar arbetet användningen av minsta medelkvadratberäkning för initialisering och en utvidgad kalmanfiltreringsmetod för realtidslägesuppskattning. Lokaliseringsmetoden beskrivs matematiskt med tanke på driftsscenarierna för en stadsbuss. Noggrannheten hos den föreslagna metoden utvärderas matematiskt. Den utvecklade lokaliseringsmetoden implementeras i ett simuleringsverktyg för kommunikation mellan fordon. Simuleringsexperiment utfördes för driftsscenarier för stadsbussar. Resultatet av initialisering med minsta medelkvadratberäkning jämförs med initialiseringen med GPS, i termer av lokaliseringsnoggrannhet. Olika inställningar av vägrensenheter jämförs med avseende på noggrannhet och uppdateringsintervall. Resultaten visar att den föreslagna metoden är möjlig för lokalisering av en stadsbuss. Denna arbetet genomfördes i samarbete med Scania AB, Södertälje.
13

Unobtrusive, Pervasive, and Cost-Effective Communications with Mobile Devices

Champion, Adam C. 25 September 2017 (has links)
No description available.
14

Reliable communication in mine environments for autonomous vehicles

Tomasi, Alessandro January 2016 (has links)
Automation in the mining industry has the potential to increase safety and productivity while improving working conditions. Ore transportation within the mine is a repetitive task which is well suited to be replaced by an autonomous mining vehicle operating around the clock. Scania, a world leader in sustainable transport solutions is investigating this new concept of vehicle. The autonomous operation is enabled by several technologies installed on the vehicle, including a communication system object of this thesis. Connectivity among vehicles is required in order to coordinate paths and exchange mission critical information. In this thesis, after identifying the challenges of wireless propagations in mines, the communication technology is chosen and possible antenna configurations and communication ranges are found. Through numerical link-budget simulations and subsequent range measurements, the potential communication range of this vehicle has been quantified. The results show the effectiveness of height diversity in extending the communication range. Lastly, the performance degradation caused by dust accumulated on the antennas is discussed. / Automatiseringen i gruvindustrin har potentialen att öka säkerheten och produktiviteten samtidigt som den förbättrar arbetsvillkoren. Malmtransporten inne i gruvan är en repetitiv uppgift som passar bra att bli utbytt av en autonom gruvtransport som är i drift dygnet runt. Scania, en av de världsledande inom hållbara tranportlösningar, undersöker just nu denna typ av fordon. Den självstyrande driften aktiveras genom att ett flertal teknologier installeras på fordonet, inklusive ett kommunikationssystem som är ämne för denna avhandling. Anslutningen mellan fordonen är nödvändig för att kunna samordna banor och ge information i för uppdraget kritiska lägen. I denna avhandling, efter att ha identifierat svårigheterna med en trådlös utbredning i gruvor, är kommunikationsteknologin vald och möjliga antennkonfigurationer och kommunikationsräckvidder funna. Genom numeriska länkbudgetsimuleringar och efterföljande räckviddsmätningar, har det potentiella kommunikationsområdet för detta fordon kvantifierats. Resultaten visar effektiviteten av mångfald när det gäller höjd när man utvidgar kommunikationsområdet. Slutligen diskuteras prestandaförsämringen orsakad av damm som ackumulerats på antennerna.
15

Konceptuell utveckling av interiören hos en framtida fullt autonom bil / Conceptual development of an interior in a future fully autonomous car

Edvardsson, Felicia, Warberg, Therése January 2016 (has links)
Målet med examensarbetet har varit att samla information åt ett tekniskt konsultföretag för att öka deras kunskap om autonoma system och fordonskommunikation. Statusen på arbetet kring dessa aktiva säkerhetssystem hos olika aktörer och hur systemen implementeras i dagens och framtidens fordon har undersökts genom omfattande litteraturstudier, intervjuer och marknadsanalyser. De autonoma systemen kan samla information från omgivningen genom sensorer och bidra till ett jämnare trafikflöde, ökad säkerhet, lättare bilar och bättre miljö. Genom fordonskommunikationen kan fordon kommunicera med varandra samt infrastrukturen och garantera en säker bilfärd. År 2030 utgörs innerstaden av autonom, elektrifierad kollektivtrafik för att transportera människor på begäran, samtidigt som personbilar till viss del förbjuds. Potentiella behov för människan i en fullt autonom bil har identifierats och diverse produktutvecklingsmetoder har tillämpats för att utforma två konceptuella lösningar för en framtida bilinteriör. Lösningarna visar interaktionen mellan människa och system eftersom underhållning och bekvämlighet blir viktigt i en fullt autonom bil. Respektive lösning är statsägd och rymmer fyra passagerare. I lösningarna är sittplatserna placerade på ett sätt som underlättar kommunikation mellan passagerarna. Passagerarna kan underhållas eller informeras individuellt eller gemensamt via text, ljud och bild. / The goal with this thesis project has been to collect information for a technical consulting company in order to increase their knowledge about autonomous systems and vehicular communication. The status of how various operators work with active safety systems and how the systems are implemented in current and future vehicles has been investigated through extensive literature studies, interviews and market research. The autonomous systems can collect information from the surrounding through sensors and contribute to better traffic efficiency, increased safety, lighter cars and a better environment. Through vehicle communication, the vehicle can communicate with each other in order to guarantee a safe ride. In 2030 the inner city constitutes of autonomous, electrified public transport to transport people on demand, meanwhile private cars are prohibited. Potential needs for the human in a fully, autonomous car has been identified and various product development methods has been applied in order to develop two conceptual solutions for a future car interior. The solutions show the interaction between human and system since entertainment and comfort becomes important in a fully, autonomous car. Each solution is state-owned and holds four passengers. In the solutions, the seats are placed in regard to facilitate communication between the passengers. The passengers can be entertained or informed individually or collectively by text, sound and images.
16

Time-triggered Controller Area Network (ttcan) Communication Scheduling: A Systematic Approach

Keskin, Ugur 01 August 2008 (has links) (PDF)
Time-Triggered Controller Area Network (TTCAN) is a hybrid communication paradigm with combining both time-triggered and event-triggered traffic scheduling. Different from the standard Controller Area Network (CAN), communication in TTCAN is performed according to a pre-computed, fixed (during system run) schedule that is called as TTCAN System Matrix. Thus, communication performance of TTCAN network is directly related to structure of the system matrix, which makes the design of system matrix a crucial process. The study in this thesis consists of the extended work on the development of a systematic approach for system matrix construction. Methods for periodic message scheduling and an approach for aperiodic message scheduling are proposed with the aim of constructing a feasible system matrix, combining three important aspects: message properties, protocol constraints and system performance requirements in terms of designated performance metrics. Also, system matrix design, analyses and performance evaluation are performed on example message sets with the help of two developed software tools.
17

Realizace zařízení pro komunikaci Car2X a Car2Car / Realization of the Car2X and Car2Car communication device

Štohanzl, Milan January 2011 (has links)
This work explores possibilities of Car2Car and Car2X communication. It contains survey of system properties, types of transmission messages, etc. It represents architecture of the system and deals with technical expectations and limitations of system. In the light of the fact that this work is created in the time, when development of this system hasn’t finished yet, the work doesn’t contain details which would allow deeper technical view about area of vehicular communication. The work also deals with the possibility of realization of device, communicating with a similar standard. Like the most suitable standard was chosen an IEEE 802.11a. Mobile unit has been realized by single board computer Mini 2440 and communication has been realized by WiFi module OWS451i, which works as AT modem. Mini 2440 and infrastructure server are based on Linux operation system.
18

A Literature Review of Connected and Automated Vehicles : Attack Vectors Due to Level of Automation

Kero, Chanelle January 2020 (has links)
The manufacturing of connected and automated vehicles (CAVs) is happening and they are aiming at providing an efficient, safe, and seamless driving experience. This is done by offering automated driving together with wireless communication to and from various objects in the surrounding environment. How automated the vehicle is can be classified from level 0 (no automation at all) to level 5 (fully automated). There is many potential attack vectors of CAVs for attackers to take advantage of and these attack vectors may change depending on what level of automation the vehicle have. There are some known vulnerabilities of CAVs where the security has been breached, but what is seemed to be lacking in the academia in the field of CAVs is a place where the majority of information regarding known attack vectors and cyber-attacks on those is collected. In addition to this the attack vectors may be analyzed for each level of automation the vehicles may have. This research is a systematic literature review (SLR) with three stages (planning, conducting, and report) based on literature review methodology presented by Kitchenham (2004). These stages aim at planning the review, finding articles, extracting information from the found articles, and finally analyzing the result of them. The literature review resulted in information regarding identified cyberattacks and attack vectors the attackers may use as a path to exploit vulnerabilities of a CAV. In total 24 types of attack vectors were identified. Some attack vectors like vehicle communication types, vehicle applications, CAN bus protocol, and broadcasted messages were highlighted the most by the authors. When the attack vectors were analyzed together with the standard of ‘Levels of Driving Automation’ it became clear that there are more vulnerabilities to consider the higher level of automation the vehicle have. The contributions of this research are hence (1) a broad summary of attack vectors of CAVs and (2) a summary of these attack vectors for every level of driving automation. This had not been done before and was found to be lacking in the academia.
19

Evaluation and Improvement of Decentralized Congestion Control for Multiplatooning Application / Utvärdering och förbättring av decentraliserade överbelastning kontroll för konvoj av fordonskonvojer

Bai, Chumeng January 2018 (has links)
Platooning has the potential to be a breakthrough in increasing road capacity and reducing fuel consumption, as it allows a chain of vehicles to closely follow each other on the road. When the number of vehicles increases, platoons will follow one another in what is referred to as multiplatooning. Many Cooperative Intelligent Transportation Systems (C-ITS) applications rely on periodically exchanged beacons among vehicles to improve traffic safety. However, as the number of connected vehicles increases, the network may become congested due to periodically exchanged beacons. Therefore, without some congestion control method, safety critical messages such as Cooperative Awareness Messages (CAMs) may not be delivered on time in high vehicle density scenarios. Both the European Telecommunications Standards Institute (ETSI) and the Institute of Electrical and Electronics Engineers (IEEE) have been working on different standards to support vehicular communication. ETSI dened the Decentralized Congestion Control (DCC) mechanism which adapts transmission parameters (message rate, transmit data rate, and transmit power, etc.) to keep channel load under control. ETSI DCC utilizes a three-state machine with RELAXED, ACTIVE, and RESTRICTIVE states. In this thesis, we implemented this three-state machine by adapting the message rate based on the channel busy ratio (CBR). We name this message-rate based three-state machine DCC-3. DCC-3 has the ability to control channel load; however, it has unfairness and instability problems due to the dramatic parameter changes between states. Therefore, we divided the ACTIVE state of DCC-3 into ve sub-states, and refer to this as DCC-7. We benchmarked DCC-3 against static beaconing (STB), dynamic beaconing (DynB), LInear MEssage Rate Integrated Control (LIMERIC), and DCC-7 using different evaluation metrics with different numbers of platoons. Our results from the Plexe simulator demonstrate that DCC-7 has the best performance when considering all evaluation metrics, including CBR, Inter-reception time (IRT), collisions, safe time ratio, and fairness. Furthermore, we found using transmit power control could greatly improve the performance of CBR and collision rates. / Platooning (fordonskonvojer) har potential att bli ett genombrott i öka vägkapaciteten och minska bränsleförbrukning, eftersom det tillåter en kedja av fordon att noga följa varandra på vägen. När antalet fordon ökar, kommer att plutoner följa varandra i vad som benämns multiplatooning (konvoj av fordonskonvojer). Många kooperativ intelligenta transportsystem (C-ITS) tillämpningar förlitar sig på regelbundet utbytte beacons bland fordon att förbättra traffiksäkerheten. Dock som antalet uppkopplade fordon ökar, kan nätverket bli överbelastat på grund av regelbundet utbytte beacons. Utan någon trängsel kontrollmetod, får därför säkerhet kritiska meddelanden såsom kooperativ medvetenhet meddelanden (CAMs) inte levereras i tid i höga fordon densitet scenarier. Både Europeiska institutet för telekommunikationsstandarder (ETSI) och Institute el och elektroniska tekniker (IEEE) har arbetat på olika standarder för att stödja vehicular kommunikation. ETSI definieras den decentraliserade överbelastning kontroll (DCC) mekanism som anpassar överföring parametrar (meddelande hastighet, överföra datahastighet och sändningseffekt, etc.) för att hålla kanalen belastningen under kontroll. ETSI DCC använder en tre-state maskin med RELAXED, ACTIVE och RESTRICTIVE stater. I denna avhandling har genomfört vi denna tre-state maskin genom att anpassa meddelande hastighet baserat på kanal upptagen förhållandet (CBR). Vi nämna detta meddelande-hastighet baserat tre-state machine DCC-3. DCC-3 har förmågan att kontrollera kanal belastning; Det har dock otillbörlighet och instabilitet problem på grund av de dramatiska parameterändringar mellan stater. Därför vi indelat det ACTIVE tillståndet för DCC-3 i fem undertillstånd och hänvisar till detta som DCC-7. Vi benchmarkade DCC-3 mot statiska leda (STB), dynamisk leda (DynB), linjära MEssage Rate integrerad kontroll (LIMERIC) och DCC-7 med olika utvärdering statistik med olika antal plutoner. Våra resultat från Plexe simulator visar att DCC-7 har bästa prestanda när man överväger alla utvärdering statistik, inklusive CBR, mellan receptionen tid (IRT), kollisioner, säker tid baserat och rättvisa. Vi fann dessutom använda Sändareffektstyrning kan avsevärt förbättra prestanda för CBR och kollision priser.
20

Estratégia adaptativa para disseminação de dados usando a força do sinal / Adaptative strategy for data dissemination using signal strenght

Correa, Cláudio 17 December 2018 (has links)
Rede Ad hoc Veicular (VANET) é um subconjunto singular das redes ad hoc móveis (MANET), com o diferencial de que os nós são veículos providos de tecnologia própria de comunicação e que interagem para formar redes espontâneas, valendo-se de pouca ou nenhuma infraestrutura estabelecida previamente. VANETs admitem a integração de diferentes tecnologias sem fio na pretensão de mitigar adversidades, agregar segurança e eficiência ao tráfego. Na disseminação de dados, um salto único é suficiente para orientar os elementos ao alcance do sinal de rádio, e nós intermediários sustentam a comunicação aos demais, em encaminhamento multihop. Amparados em dispositivos embarcados, os veículos produzem registros, detectam sinais, trocam advertências e métricas. Avaliações dessas informações permitem ao condutor decisões ou reações antecipadas em situações adversas, a exemplo dos acidentes ou congestionamentos. Nesse contexto, a execução deste trabalho trata questões para elaborar estratégias adaptativas inteligentes de disseminação de dados, uma vez que as mesmas se consolidam como lastros da comunicação em VANET com condições adversas de operação. A abordagem proposta se utiliza de sistemas fuzzy para a detecção de congestionamento, com o propósito de agregar autonomia e adaptar a estratégia de disseminação às condições de tráfego identificadas. A convergência nos desenvolvimentos realizados se reflete na estratégia eFIRST, uma solução robusta para a detecção autônoma da condição atual de congestionamento que resguarda a disseminação adaptativa de alertas e abranda o problema da interrupção no tráfego. A abordagem se sustenta apenas na comunicação entre veículos e nos registros de identificação da vizinhança local, agregados em uma estratégia fuzzy e no ajuste adaptativo da potência do sinal de transmissão. Em conformidade com as tendências de condução e com os sistemas inteligentes, este desenvolvimento contribui com subsídios para ratificar a aproximação fuzzy como estratégia adaptativa às flutuações na densidade veicular, em diferentes cenários e regimes de tráfego. As avaliações comparativas do eFIRST respaldam concluir que a estratégia oportuniza o equilíbrio otimizado das perdas, colisões e cobertura, com superior alcance de propagação e redução dos congestionamentos. / Vehicular Ad hoc Network (VANET) is a unique subset of mobile ad hoc networks (MANET), with the difference that nodes are vehicles provided with their own communication technology and interact to form spontaneous networks, with little or no infrastructure previously established. VANETs support the integration of different wireless technologies in order to mitigate adversities, add security and efficiency to traffic. In the data dissemination, a single hop is sufficient to guide the elements within reach of the radio signal, and intermediary nodes support the communication with the others in multihop routing. Supported by embedded devices, vehicles produce records, detect signals, exchange warnings and metrics. Assessments of this information allow the driver to make decisions or react beforehand in adverse situations, such as accidents or traffic congestions. From the observations in this context, this work deals with questions to elaborate intelligent adaptive strategies in data dissemination, since they consolidate themselves as ballast communication in VANET with adverse operating conditions. The proposed approach uses fuzzy systems to detect traffic congestion, with the purpose of aggregating autonomy and adapting the dissemination strategy to the identified traffic conditions. The convergence in the developments performed is reflected in the eFIRST strategy, a robust solution for the autonomous detection of the current traffic congestion condition that protects the adaptive dissemination of alerts and reduces the problem of the interruption in the traffic. The approach is supported only by communication between vehicles and in local neighborhood identification records, aggregated in a fuzzy strategy and in the adaptive adjustment of transmission signal power. In accordance with the driving trends and with the intelligent systems, this development contributes with assistance for ratify the fuzzy approach as an adaptive strategy to fluctuations in vehicular density in different scenarios and traffic regimes. Comparative evaluations of eFIRST support the conclusion that the strategy favors the optimal balance of losses, collisions and coverage, with a greater range of propagation and reduction of congestion.

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