Current Issue : April - June Volume : 2012 Issue Number : 2 Articles : 4 Articles
This paper focuses on routing for vehicles getting access to infrastructure either directly or viamultiple hops through other vehicles.\nWe study routing protocol for low-power and lossy networks (RPL), a tree-based routing protocol designed for sensor networks.\nMany design elements from RPL are transferable to the vehicular environment. We provide a simulation performance study of\nRPL and RPL tuning in VANETs. More specifically, we seek to study the impact of RPL�s various parameters and external factors\n(e.g., various timers and speeds) on its performance and obtain insights on RPL tuning for its use in VANETs. We then fine tune\nRPL and obtain performance gain over existing RPL....
Clustering in vehicular ad hoc networks (VANET) is one of the control schemes used to make VANET global\r\ntopology less dynamic. Many of the VANET clustering algorithms are derived from mobile ad hoc networks\r\n(MANET). However, VANET nodes are characterized by their high mobility, and the existence of VANET nodes in the\r\nsame geographic proximity does not mean that they exhibit the same mobility patterns. Therefore, VANET\r\nclustering schemes should take into consideration the degree of the speed difference among neighboring nodes\r\nto produce relatively stable clustering structure. In this paper, we introduce a new clustering technique suitable for\r\nthe VANET environment on highways with the aim of enhancing the stability of the network topology. This\r\ntechnique takes the speed difference as a parameter to create relatively stable cluster structure. We also developed\r\na new multi-metric algorithm for cluster-head elections. A simulation was conducted to evaluate our method and\r\ncompare it with the most commonly used clustering methods. The simulation results show that our technique\r\nprovides more stable cluster structure on the locale scale which results in a more stable network structure on the\r\nglobal scale. The proposed technique reduces the average number of clusters changed per vehicle by 34-46%, and\r\nincreases the average cluster lifetime by 20-48% compared to the existing techniques....
The deployment of a fault diagnosis strategy in the Smart Distance Keeping (SDK) system with a decentralized architecture is\r\npresented. The SDK system is an advanced Adaptive Cruise Control (ACC) system implemented in a Renault-Volvo Trucks vehicle\r\nto increase safety by overcoming some ACC limitations. One of the main differences between this new system and the classical ACC\r\nis the choice of the safe distance. This latter is the distance between the vehicle equipped with the ACC or the SDK system and the\r\nobstacle-in-front (which may be another vehicle). It is supposed fixed in the case of the ACC, while variable in the case of the SDK.\r\nThe variation of this distance depends essentially on the relative velocity between the vehicle and the obstacle-in-front. The main\r\ngoal of this work is to analyze measurements, issued from the SDK elements, in order to detect, to localize, and to identify some\r\nfaults that may occur. Our main contribution is the proposition of a decentralized approach permitting to carry out an on-line\r\ndiagnosis without computing the global model and to achieve most of the work locally avoiding huge extra diagnostic information\r\ntraffic between components. After a detailed description of the SDK system, this paper explains the model-based decentralized\r\nsolution and its application to the embedded diagnosis of the SDK system inside Renault-Volvo Truck with five control units\r\nconnected via a CAN-bus using ââ?¬Å?Hardware in the Loopââ?¬Â (HIL) technique.We also discuss the constraints that must be fulfilled....
Recently, the IntelliDrive initiative has been proposed by the US Department of Transportation (USDOT) to enhance on-road\r\nsafety and efficiency. In this study, we provide a mathematical framework which predicts the effect of such technologies on the\r\nefficiency of multilane highway systems prior to their real-life deployment. Our study shall encompass mixed traffic conditions in\r\nwhich a variety of assisted, automated and unequipped vehicles coexist. We show that intervehicular communications improves\r\nthe flow of vehicles by reducing the perception-reaction (P-R) times of drivers and, in some cases, allowing for more efficient\r\nlane-changing operations. As we shall see, unlike the latter, the former effect of IntelliDrive on driver P-R time is always there,\r\nregardless of the specific traffic conditions....
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