Design And Implementation Of RFID Read-write Device In Indoor Positioning Applications

As the modern science and technology develop,wireless communication technology and information recognition technology are applied in many fields and become hot issues.One of the most popular communication technologies,Radio Frequency Identification(RFID),makes the non-contact information transmission possible and also contributes to non-contact automatic identification technology in the light of the spatial coupling principle of radio-frequency signal.Nowadays,this technology has became a big concern in theoretical researches and also used widely in the daily life.For instance,identification recognition,public transport,logistics,access control system and industrial management and control.The topic of this thesis comes from the author’s involvement in "the 2011 National University of innovative experimental projects" ZigBee-based family service robots and"robot RFID-based indoor positioning" project.It is widely known that robot self-localization based on landmarks is the major method used.The thesis tries to explore how RFID is applied or implemented in robot indoor positioning by designing one kind of positioning system of robot.Therefore,the content of this thesis consists of four parts:at the beginning part,the introduction of RFID is mentioned which involves the structure,operating principles,the development and the application of RFID.Then,the previous and prevalent applications of indoor location system in daily life have been analyzed.Based on these reviews about the application and researches on RFID,this thesis has provided a kind of RFID indoor location system whose operating frequency is 13.56MHz.This kind of technology analyzed in this thesis can exchange data in the way of non-contact bidirectional communication with the help of radio-frequency signals.This thesis also consists of several projects on the hardware side,which include the designs of reader unit and control unit(using STM32F103VET),the communications interface and antenna.Among them,dedicated chips Fm1702SL designed by Fudan Microelectronic Co.,Ltd.(based on the ISO 14443 standard)is used in reader module as the RF front-end of RFID Reader.In this way,with the rational design of matching circuit and the antenna,the modules have reached the maximum read-and-write distance.Apart from this,Mifare I passive RFID tags is used for validation testing.On the software side,the control software system is put forward in this thesis based on UC/OSLL V2.86 real-time operating system,which is used in designing the physical layer and application layer.Also,the control of RF front-end,the application of landmarks in RFID,synchronous working of several card readers,data processing,robot positioning are involved in the project.The findings of this thesis show that the RFID reader and the robot positioning system can implement basic functions and satisfy the requirements of the design after several tests.The read distance ranges from 60mm to 100mm,which reach the maximum of requirement of ISO system and achieve the positioning accuracy and auto navigation.More attention is encouraged to be paid in algorithm and path planning in further studies.