Multi-antenna UHF RFID System Identification Reliability Research And Implementation

With the development of wireless communication technology, RFID technology is being increasingly to be applied to a wide range of fields. Automobile industry has always been the cutting edge of technological change and innovation for manufacturing production mode. And it promotes the revolution of manufacturing production mode in worldwide with its huge industry scale. Therefore, the auto industry will be an important direction for RFID applications.RFID technology is more automated, identification farther, identification faster, more flexible in read and write operation comparing with the traditional bar code technology. So this technology has been used in the production line by some vehicle manufacturers in order to control quality and manage process for the vehicle and components production. Finally, this technology effectively improves manufacturing processes of the production line, increase productivity, improve production methods and cost savings.However, one or more electronic tags could not be correctly identified because automobile production environment is extremely complex, such as electromagnetic interference, the metal material restrictions, environmental conditions change. Therefore, some auto components can not be detected since these influences, and the RFID technology application in the automotive production line is seriously affected. Existing RFID reader with a single antenna is difficult to ensure the reliability of multi-tag identification because of blind spots and much interference in the UHF segment.This dissertation proposes the multi-antenna identification mode by increasing the antenna number of RFID reader. Multiple antennas connected with the reader are reasonably deployed in different position in the identification regions. And this identification mode can enhance coverage effect, reduce the blind spots and improve the reliability of multi-tag identification.Firstly, the reliability model of multi-antenna is established and theoretically verified the correctness and feasibility of the program in order to implement the multi-antenna mode identification program. Based on the multi-antenna mode, reader can get the parameter value of reliable identification rate u by individual identification results of multiple antennas and let this value as the assessment parameter of the identification results. Additionally, optimal control algorithm of multi-antenna is designed based on this parameter in order to reduce the identification time.From the theoretical analysis and experimental test analysis shows that the UHF RFID reader by multi-antenna identification mode can improve the success rate of identification and the reliability of system identification, so that these influences of unreliability are reduced in the system identification process. In addition, the reliable identification rate u that was obtained by multi-antenna identification mode can evaluate the results of the identification, and this parameter provides a reference for users. Finally, the analysis confirmed that actual number of used antenna can be controlled according to the actual identification situation by multi-antenna identification mode, and the purpose of reducing the system identification time is achieved.The test results show that reader can obviously improve the reliability of multi-tag identification by multi-antenna identification mode. And this method is a new way that improves the reliability of multi-tag identification for the UHF RFID reader.