碩士 / 朝陽科技大學 / 網路與通訊研究所 / 95 / The main goal of vehicle navigation systems is to determine the optimal routing path for achieving the least travel time and exhausted gasoline. Most navigation systems use the static shortest path routing algorithm based on a digital geographic map or use optional traffic information broadcasted by a centralized Traffic Information Center (TIC) to avoid routing to heavy traffic load roads. Since the traffic information may be gathered from few monitoring devices that only covers some specific highways and roads, it results in some disadvantages, including only supporting partial traffic information on some roads, long update period and low reliability of using a centralized TIC. In consequence, the determined route could be the shortest distance route but it may not meet the demands of the optimal routing: the least travel time and exhausted gasoline. Moreover, most intelligent transportation systems (ITS) adopt IEEE 802.11 (i.e., WiFi) as the data transmission interface. Unfortunately, WiFi only supports short transmission range and low mobility. It thus degrades the efficiency of the inter-vehicle communications (IVC). Therefore, we propose herein the wireless sensor network-based adaptive navigation approach, which uses the WiMAX multihop relay networks as the IVC interface to increase the reliability and efficiency of inter-vehicle communications. In addition, the real-time traffic information could be gathered from various types of sensors equipped on vehicles and exchanged among neighbor vehicles. As a result, the navigation system can obtain three metrics of the road traffic density, road class and road distance to determine the optimal route. Numerical results indicate that the proposed adaptive navigation approach outperforms other approaches in the average travel time and average exhausted gasoline while yielding competitive average travel distance. Furthermore, the worst case running time of the proposed approach is analyzed, which requires and time in high-density and sparse vehicle environments, respectively, where is the number of vehicles, is the number of roads and is the number of road intersections.
| Identifer | oai:union.ndltd.org:TW/095CYUT5650013 |
| Date | January 2007 |
| Creators | Bo-Jhang Huang, 黃柏彰 |
| Contributors | Ben-Jye Chang, 張本杰 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 45 |
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