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On the basis of not changing the existing highway toll method, the actual driving path of the vehicles driving on the highway is “point-taking” tracking and monitoring, so as to realize the “visual management” of the highway vehicle driving path, effective control and Put an end to the occurrence of “arrears and evasion” of vehicles.
At present, most domestic high-speed highways are closed networked highway systems. After a vehicle enters the expressway from an entrance, it can exit the expressway network from the corresponding exit according to its destination. The highway toll that the vehicle should pay is calculated based on the entrances and exits it passes through. However, after entering the highway, in order to pay less highway tolls, the driver will conduct irregular behaviors such as changing cards midway and car changing lanes, thereby concealing the true driving path of the vehicle. This situation has caused huge economic losses to the road management department. It is very necessary to track and record the true driving path of a vehicle in the highway system through technical means.
Based on the above project requirements, the monitoring method is considered to be point-based, rather than full-program. Because the whole program monitoring is difficult to achieve in terms of technology and cost, and it is not necessary to achieve the purpose of this project. On the contrary, the point-based monitoring technology is mature and the cost is relatively low, and it is easy to achieve the purpose of monitoring the driving path of the vehicle.
The working frequencies of RFID for transportation are generally ultra-high frequency band (868915MHz) and microwave frequency band (2.45GHz and 5.8GHz). At present, the typical frequencies used in road traffic at home and abroad are 915MHz and 5.8GHz. The differences between the two include the following:
1) 915M can use passive tags and active tags, while 5.8G is mostly active tags. The active tag contains a long-life battery (about 5 years), which can actively send a signal to the reader;
2) The read and write distance of 915M is slightly shorter than 5.8G, 915M is 5 meters, and the 5.8G system can reach up to 100 meters depending on the tag and antenna;
3) 5.8G is more directional than 915M, improving accuracy;
4) The data transmission speed of 5.8G is faster than 915M, which can meet the moving speed of the label carrying unit under 200 km/h;
5) 5.8G has stronger anti-interference ability and can work in rainy, snowy and humid environment;
6) The cost of 5.8G related equipment is higher than that of 915M;
In China, both frequency bands have been put into use. In 2003, the Ministry of Transport issued the “Notice on Issues Concerning the Special Wireless Short-range Communication System for Intelligent Traffic Management in the 5.8GHz Frequency Band”, which included 5.8GHz as the recommended standard for the dedicated short-range communication frequency used by the vehicle automatic identification system. Therefore, combining the above aspects, this program plans to use 5.8G as the working frequency of RFID.
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