基于相位差测距的RFID室内定位系统设计

摘要

针对当前室内定位的广泛需求及传统室内定位技术的缺陷,设计了一种基于相位差测距的射频识别(RFID)室内定位系统.系统主要由RFID阅读器、电子标签、STM32模块组成,3个电子标签固定在特定位置作为信标节点,1个RFID阅读器作为移动节点发射与接收超高频信号,STM32模块根据测得的相位差计算相应的距离,并利用改进后的三边定位法,确定阅读器的位置.在实验室对进行了设计并测试,结果表明:该系统能很好地完成定位功能,定位精度达到厘米(cm)级,可满足众多领域的应用需求.%In order to overcome shortcomings of traditional indoor positioning technology and meet a large number of the current indoor positioning needs,design a kind of radio frequency identification (RFID) indoor positioning system based on phase difference ranging,which is mainly composed of a RFID reader,electronic tags and a microprocessor module. 3 electronic tags are fixed at particular positions as beacon nodes,and a RFID reader can transmit and receive ultra high frequency signals as mobile node. The STM32 calculates the corresponding distance between two points according to the phase difference,and ultimately determines the location information of the reader through the improved trilateration localization algorithm. The system is designed and test in laboratory,the results show that the system can perfectly achieve the positioning function,and positioning precision reaches cm level,that can meet the application needs of many fields.