- 學位論文
車輛行進中近場即時交通資訊平台研究
Traffic Information Transmission through Short Range Wireless Communication Technology for Enroute Vehicles
摘要
目前政府已成功開發諸多便民的線上交通資訊查詢系統—ATIS，然而受限於上網環境，以及系統間的資訊經常缺乏一致性，而造成可信度和便利性降低，所以本研究目的乃統一各系統間資訊交換之標準，使各單位資訊能夠互用，避免資訊不一致以及社會資源浪費。 考量未來之發展性，本研究參考美國NTCIP通訊協定基礎架構，以及歐美日各國道路與車合作系統發展現況，作為在NTCIP通訊協定基礎架構下，制定車與路及系統即時交通資訊之標準協定、參數內容與功能之基礎。 經回顧歐美日道路基礎設施與車合作相關系統後發現，歐美日系統所發布之資訊基本上可納入三個領域，分別為：道路交通標誌標線號誌、緊急事件通報和交通路況資訊，所以本研究在道路交通標誌標線號誌部分，乃參考交通部頒布之「道路交通標誌標線號誌設置規則」為基礎，進行TMIB之編定；緊急事件通報則根據2004年版ITS綱要計畫中，針對EMS使用者所定義之服務項目為基礎，進行TMIB之編定；而交通路況則以高速公路資訊可變標誌內容顯示原則為基礎。其中交通標誌的範圍極廣，且交通標誌各分類內物件資料元素具有許多重複性，為了降低無謂的封包浪費，本研究擬訂了交通標誌篩選分類群組機制，經此機制分類與編碼結果分析後可知，傳送各標誌能夠有效減少封包量，亦能減低整體通訊網路負擔。 另外，本研究考量封包在異質性網路傳輸時，因為MTU(Maximum Transmission Unit)之不同，封包可能被切割而無法重組，而擬訂一機制以確保封包內容與格式之完整性，所以本研究在此基礎與架構下，以J2ME程式語言為平台，建立近場即時交通資訊交換平台，達成跨單位(ATIS-車-RSU)資訊共享之目標，以提升行車安全與資訊有效利用，而此平台之程式架構主要由三個模組組成，分別為STMP編碼程式模組、STMP解碼程式模組和判斷與顯示程式模組。 在建構好近場即時交通資訊平台後，本研究利用此平台對研究中新增的車與路及系統即時交通管理資訊庫(TMIB)之內容，進行實驗室階段之測試與驗證，結果顯示本研究所選之20個物件，其編碼、解碼和顯示動作皆正確。最後，經由路側發送訊息到行進中車輛上之實際測試與驗證後可知，本研究建立之平台和封包格式與機制，確實能夠達成近場即時交通資訊之通訊，而封包部分在重組時也能確保封包完整性。
並列摘要
Many convenient on-line Advanced Traveler Information Systems (ATIS) have been developed by government so far. However, the usages of these systems are limited to the access of internet, and lacking in consistency of information. These deficiencies would debase its reliability and convenience. Therefore the main purpose of this research is to unify the standards applied among different traffic information systems, in order to ensure the consistency of information and improving the efficiency of resource utilization. Under the consideration of future development, the NTCIP protocol and the present road-vehicle communication technique of other advanced countries such as U.S.A., Japan, and countries in Europe, whose situations of development would be applied for the base of this research, to establish standards among roadside units and onboard units including protocol, parameters and their functions. Drawn from the progress in applications of communication technique between roadside infrastructure and vehicle on-board units abroad, the conclusion is that the information spread by these systems can be divided into three parts generally. The first is the information of traffic signs, signals and marks. The second is the announcement of emergent incident and the last one is the information of traffic condition. Therefore the regulation of signs, marks and signals for road traffic applied in Taiwan is adopted as reference to draw up TMIB. In addition, both of the service definitions for EMS users of ITS skeleton scheme 2004 and the principles of CMS messages display are referred as basis of this research. Among of the TMIB, the range over regulation of signs are very wide, and the data elements of this classification has high repetition, so for the objective of minimum size of packet, this research draw up a classification method, if we utilizing this method, it will reduce a lot of packet, and also lower the load of the whole internet. Moreover, in order to prevent the problem of recombination after segment of packet, a mechanism for ensuring the completeness of packet format in heterogeneous network was designed. Based on this framework, this research uses J2ME as programming language, building up a real-time traffic information interchange platform. Besides, not only the objective for information sharing among ATIS, vehicles on-board units and RSU can be accomplished, but it could also improve the traffic safety and the efficiency of information utilization. This platform includes three modules: the STMP encode module, the STMP decode module, and the judgment and display module. After constructing the interchange platform for the real-time traffic information, this research carries out a test and confirmation of laboratory stage. The test result(encode, decode, display) shows that 20 objects chosen from TMIB succeeded in this test. Moreover, a mechanism for ensuring the completeness of packet format in heterogeneous network was designed, and also has been verified successfully after several practical experiments between enroute vehicles and RSU.