車載通訊應用於降低交通事故發生率之研究

Abstract

交通事故一旦發生，便會造成人們生命財產嚴重的損失，為了減少事故所造成的傷害，一些相關的研究機構便開始發展與行車安全相關的技術。利用無線網路傳遞緊急資訊來提醒用路人，是預防交通事故的研究課題之一。然而，車間網路通訊具有高速移動與高速變動的特性，增加了在車輛間通訊的挑戰與難度。近年幾年來，為了因應車間網路的特性，發展了IEEE 802.11p WAVE/DSRC的通訊標準，而本研究，便是在此一架構下進行。 為了提升緊急訊息的即時性與正確性，並減少訊息的傳輸時間，我們提出一套傳輸機制，藉由車機的感測裝置收集到路上的即時資訊來動態的調整訊息傳輸的順序，以加強頻寬的使用分配以及縮短訊息的傳輸延遲，並且利用計算最小安全距離的方式，選擇出需要被緊急通知的車輛發送特定訊息，以減少車輛碰撞的機率降低交通事故的發生。本論文最後透過NS-2進行模擬實驗，實驗結果顯示本傳輸機制可以在一般駕駛者可因應的反應時間內將緊急訊息即時且正確的傳達。

Road traffic accidents bring serious injuries and property damage. The development and improvement of the technologies for vehicular safety can significantly reduce the accident rate and improve road safety. Transmitting emergency messages in the wireless vehicular networks to inform drivers is the major topic of researches for preventing traffic accident. However, the unique characteristics of vehicular networks such as high speed and high variety of relative position leading challenges and arduousness in vehicular communication. In the recent years, IEEE 802.11p WAVE/DSRC has being developed for vehicular network. Our research is working on this architecture. In this study, we proposed a warning message transmission scheme which adopts two strategies to achieve low transmission delay for emergency message. The results of our simulations on NS2 show that when dangerous event happens on the road, warning messages can be sent immediately and drivers can have enough time to do right decisions to react this emergency event.