路口防撞系統基於車間無線通訊之效能評估

Performance Evaluation of Intersection Collision Avoidance System using Vehicle-to-Vehicle Communication

邱柏睿(Po-Jui Chiu)

指導教授 ： 蔡欣穆

國立臺灣大學/電機資訊學院/資訊工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.02736

摘要

根據FARs以及GES調查，在美國，2008年之中有2,307,000件交通事故發生於路口，約占了在2008年所有交通事故的百分之四十。而在這些事故之中，其中733,000件造成人員受傷、7,421件造成人員死亡。基於路口事故頻繁，本論文提出一”路口防撞系統”，利用現今成熟的無線技術:IEEE 802.15.4以及IEEE 802.11n來實作，其低廉成本，可廣泛應用於車間通訊，於接近路口時發送警告訊息，告知其他車輛進行反應。並對此應用在多個不同路口與情境下進行實驗，實驗中包含了路徑衰減指數、封包接收率等測量。同時，根據實驗數據進行模擬分析，計算車輛收到封包並煞車避免事故 之成功機率能否達到99%，以驗證此防撞系統在無線訊號高度衰減的情況下之可行性。另一方面，為確保將移動無線裝置如智慧型手機應用於此系統的可靠度，提出一 ”傳輸範圍增幅器”，目的在於增加手機無線網路訊號最大傳輸範圍，以及增加擴充外接天線之功能。同時針對該裝置提升效果進行分析，以驗證其效能是否符合 此防撞系統之應用。

關鍵字

車間網路 ； 無線通訊 ； 無線測量 ； 路口 ； 防撞系統

並列摘要

According to Fatality Analysis Reporting System (FARS) and General Estimates System (GES), an estimation that 2,307,000 crashes occurred at intersections across the United States in 2008. This accounts for about 40 percent of the 5,811,000 crashes that occurred in 2008. Among these, 7,421 were fatal crashes and in 733,000 crashes one or more occupants suffered injuries. To this end, we propose a cost-effective collision avoidance system which utilizes non-line-of-sight (NLoS) communication links between vehicles on intersecting roads. Both IEEE 802.15.4 and 802.11n links measurements were carried out to investigate the path loss and the packet reception rates of those NLoS links at different intersections. Analysis of the results suggests that NLoS links at intersections, while exhibiting high path loss, are still more than sufficient to support the required vehicle-to-vehicle (V2V) communications for the proposed system to avoid 99% of the possible collisions at intersections. To enable the use of the smartphone and compensate for its smaller built-in antenna, we also designed and implemented a transmission range extender to double the transmission range and ensure that the performance is sufficient for the proposed collision avoidance system.

並列關鍵字

Collision avoidance system ； NLoS ； Intersection ； Link measurement ； Vehicle-to-vehicle communication ； VANET ； V2V ； Pathloss exponent ； IEEE 802.11n ； IEEE 802.15.4

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