基于低频触发的高精度RFID定位系统的设计与实现

摘要

In order to solve the problems of poor positioning accuracy and high power consumption of electronic tags in the traditional RFID positioning technology,a design scheme of 2.4 GHz high accuracy regional positioning system based on low frequency trigger was proposed.The scheme combined the low frequency 125 kHz trigger signal with the 2.4 GHz radio-frequency signal,the power consumption of the electronic tag was greatly reduced by the method of low frequency wake,the positioning accuracy of RFID system could be further improved by using the trigger mechanism which could adjust the trigger distance,2.4 GHz active electronic tag,125 kHz trigger and 2.4 GHz reader were designed based on the proposed scheme.The separation design of reader and trigger reduced the cost of layout.In the design of system hardware circuit,the adjustable potentiometer and digital voltage regulator were added to adjust the recognition distance and the trigger distance,these made the configuration of the equipment more convenient and enhanced the practicability of system.The testing data showed that the maximum communication distance between the reader and the tag was 120 m,standby time of active electronic tag can be about 2 years,the positioning accuracy was 1-5.2 m.The result verifies the effectiveness of the proposed scheme.%为了解决传统RFID定位技术中存在的定位精度差和电子标签功耗高这2个问题,提出了一种基于低频触发的2.4 GHz高精度区域定位系统的设计方案.该方案将低频125 kHz触发信号与2.4 GHz射频信号相结合,采用低频唤醒的方法极大降低了电子标签的功耗,利用可调节触发距离的触发机制将RFID系统的定位精度进一步提高.基于该方案设计了2.4 GHz有源电子标签、125 kHz触发器和2.4 GHz阅读器三个子系统.阅读器与触发器的分离式设计,节约了铺设成本.系统硬件电路设计中加入了可调电位器和数字电压调节器,分别对识别距离和触发距离进行调节,使设备的配置更为方便,增强了系统的实用性.测试数据显示,阅读器与标签的最大通信距离长达120 m,有源电子标签的待机时间约为2 a(年),RFID定位系统能够实现1~5.2 m的可调定位精度.测试结果验证了该方案的有效性.