外文翻譯---基于無線傳感器網(wǎng)絡(luò)技術(shù)的運(yùn)輸網(wǎng)絡(luò)智能引導(dǎo)及控制系統(tǒng)-文庫吧資料
2025-05-22 10:09本頁面
【正文】 ravel time of a vehicle prises the running time on the road and the waiting time for the green light at the intersection. For the ease of discussion, the following a few denotations are defined. Node: The intersection. It is denoted as Ni.(i=0,1,2 ? ) Link: the road from an intersection Ni to a successive intersection Nj. It’ s denoted as Li,j. Link is oneway. Say, Lij≠ L,ij. Total Travel Time (TTT): The total time spent while a vehicle travels from the origination to the destination along a specified route. Link Travel Time (LTT): the time spent while a vehicle travels from a node to the other node along the link. Link Average Velocity (LAV): the average velocity of all the running vehicles in the link. Waiting Greenlight Time (WGT): The time elapsed when a vehicle or a queue waits the righttogo phase in the front of an intersection. The parameter of WGT includes node, ining link, outgoing link, and the time when the vehicle reach the intersection. So it can be denoted as WGT(Node,Lin,Lout,Time). Total Travel Length (TTL): the total route length that a vehicle traveled. The basic idea of the optimization algorithm is that: Before we choose the next link to ride, we firstly predict the time cost of the candidate routes. The route with the minimum cost is then chosen as the best route. In order to predict the total time cost, we should know the travel time in all links to pass and the waiting time before every intersection. Let’ s see a simple situation. As shown in , the current time is τ 。 the roadside unit along both sides of the road。 2) some are measured by the surveillance subsystem, such as the mean speed, the number of the vehicles on a link。 the Navigation system (electronicmap and satellitebased positioning system) is installed in the vehicle for vehicle locating and navigation. The target of an ITS is to optimize the traffic in a transportation work by controlling the signal lights in the intersections, by providing the accurate traffic information in the VMS, or by selecting the best route in the emap. To perform the traffic control, below, we shall first have a look at the configuration of the transportation work. Then, some parameters are introduced to describe traffic information in the work. By optimizing these parameters, the proposed optimization algorithm is expected to optimize the traffic in the transportation work. As a example of a reallife traffic work, Fig. 2 illustrates the road of Fukuyama city [11]. On the figure some parameters such as the link length, lane numbers, and legal speed are marked on it. In this paper, we consider the traffic system that contains 3 types of basic elements, ., intersection (N), Link (L) and Vehicle (V). An Intersection can be described by 2 parameters: 1) the phase type (the type of the vehicles on different lanes passing through the intersection simultaneously)。 in [6], Di Febbraro presents a hybrid Petri Net module to address the problem of intersection signal lights coordination. The control subsystem controls the signal lights on the intersection. The guiding subsystem provides the realtime traffic information for the drivers to select the best route. The navigation subsystem uses satellite signal such as GPS to locate the specific vehicle, and with the help of electronic map, select the optimal route for the vehicle. One shortage of the systems mentioned above is that the sensors can only detect the vehicles in a fixed spot. They can not track the vehicles out of the spot. Clearly, if we can monitor and measure the traffic status dynamically in real time, an efficient traffic control will be easier to realize. With the developmen
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