RFID-Based E-Plate Identification System For Vehicle Management

Radio Frequency Identification(RFID) technology is a field that develops rapidly in automatic identification technology with many advantages such as high security,good environment adaptability,long distance recognition,rapid recognition and so on.Therefore,it is expected to have important application in intelligent transportation management.Combining with the need of the development of e-plate,a new e-plate is developed by adhering active RFID module to a traditional license plate by making a research on the design of slot antenna on metal license plate. Meanwhile a management system based on it is also developed in this paper.This RFID-based e-plate identification system is convenient for the automatic identification of the vehicle,and it meets the requirement of intelligent transportation system(ITS).Firstly,the study status and trends in the development of RFID technology and the current e-plate are summarized in this paper.The basic composition,operational principle and classified method of RFID system are discussed systematically as well as the basic electrical parameter of antenna.Then,the elementary theory of slot antenna is introduced emphasized.Secondly,according to the structure characteristics of 92 type traditional vehicle license plate of China with using slot antenna on metal license plate,the e-plates are designed respectively operating at 2.45GHz RFID frequency band and the RFID frequency band(920MHz～925MHz) of our country by Ansoft HFSS electromagnetic field simulation software,and the feed structure is designed according to the actual situation of installing the license plate.The numerical simulation and test demonstrate that the designed e-plate antenna has desired impedance bandwidth and multi-beam radiation pattern.The result of preliminary highway measure indicates that the actual measured farthest read range in a more spacious place is about 97m,while the range in vehicles crowded place is 75m,which is able to meets the need of e-plate identification system.In this paper,the impact of structure parameters changing on the work-band is studied,and such slot antenna design methods and regularities are also given.The impact of resin filling in the slot on the performance of the antenna and its improved design are also discussed.In addition,taking into account the technological requirements of the license plate production,a new type license plate based on the structure of single-sided copper clad plate is proposed experimentally,and a simple horizontal slot antenna is designed on this license plate.The impact of structure parameters changing on the radiation pattern is analyzed through numerical simulation,and the most suitable structure parameters of the antenna are determined finally.Taken the urban road with 4 traffic lanes as an example,the article has discussed the reading problem of the antenna.Last,a comprehensive e-plate management system is developed with C# language and SQL Server 2000 database.The serial communication design of each read/write function module in the management system is discussed in detail,and synthesis debugging of the software and hardware is executed.The work process of the entire e-plate management system is demonstrated finally.