Research On Synchronized Detection System Of Electronic License Plate And License Plate Based On Photoelectric Sensor

In recent years,the number of car ownership is increasing.In this process,traffic violations such as fake license plates,decks and deliberately shielding license plates will become more and more common,which makes road congestion and parking increasingly prominent.This has brought serious troubles to the daily traffic management and service work.Therefore,it is particularly important to accelerate the development and application of the electronic vehicle identification(EVI).With the development of Internet of Vehicles,photoelectric sensing and radio frequency identification technology(RFID)have been developed and applied.EVI is an UHF RFID tag.With the advantages of high efficiency,high accuracy and non-contact,the photoelectric sensing technology plays an important role in the process of EVI reading.The combination of photoelectric sensor technology and RFID has also become a research hotspot in the field of RFID.Therefore,using photoelectric sensing technology to research the synchronized detection of EVI and license plate is of great significance to accelerate the development and application of EVI.In this paper,RFID technology,photoelectric sensing technology and license plate recognition technology are combined to study the dynamic performance and sensitivity of RFID tags.At the same time,the definition of tag group sensitivity is proposed.A synchronous acquisition system of EVI and license plate is designed.The synchronous acquisition system realizes the synchronous acquisition of EVI and license plate,the dynamic performance parameters of RFID tag and the sensitivity of RFID tag.The studies provide technical support for the promotion of EVI and the research of RFID technology.The research contents of this thesis are as follows:(1)The synchronous acquisition technology of EVI and license plate based on photoelectric sensor is proposed,which combines photoelectric sensing technology,RFID technology and license plate recognition technology.The synchronous acquisition optoelectronic system can realize the recognition of EVI and license plate,and verify the results of each other in different situations,and verify the results of reading each other,so as to realize the accurate identification of the vehicle.(2)The synchronous acquisition photoelectric system can be used to test the dynamic performance parameters of RFID tag such as single tag reading distance,tag group reading rate and the reading distance of tag group when all tags are read,which provides a new test platform for the dynamic performance test of RFID tag.(3)A test method of tag sensitivity based on RFID tag recognition distance is proposed.According to EPC global international standard,the sensitivity of RFID tag can be expressed by the threshold power of tag.Therefore,when the parameters of electromagnetic wave wavelength,output power of RFID reader,antenna gain of RFID reader,antenna gain of RFID tag and power transmission efficiency are known,according to Friis transmission formula,the sensitivity of RFID tag is only related to the identification distance.The tag recognition distance can be used to calculate the sensitivity of RFID tag.The Tagformance system is also used to verify the tag sensitivity.Through the data comparison and analysis,the feasibility of this method is proved,and the influence of electromagnetic field in the environment is quantified.At the same time,the sensitivity of RFID tags group is defined,that is,the minimum power value that can make the whole RFID tags group work.(4)A vehicle speed measurement method based on RFID technology is proposed.When the RFID tag on the analog car is read accurately by the RFID reader,the distance between the RFID tag and the reader antenna can be calculated by testing the signal intensity of the tag.The distance between the beginning and end of the speed measuring area and the driving speed of the analog car can be obtained.The feasibility of the system is verified by an example test.This method provides a reference for the research of automobile speed measurement..