基于UHF RFID技术的室内定位方法  

Indoor positioning method based on UHF RFID technology

作　　者：魏海红[1] 李淑飞[2] WEI Haihong;LI Shufei(College of Electronic Information,Dongguan Polytechnic,Dongguan,Guangdong 523808,China)

机构地区：[1]东莞职业技术学院电信信息学院,广东523808 [2]东莞职业技术学院人工智能学院,广东523808

出　　处：《自动化与仪器仪表》2024年第11期34-38,共5页Automation & Instrumentation

基　　金：东莞市科技特派员项目,智能功率芯片的过问保护研究及其电路设计(20221800500842);东莞职业技术学院智能终端及智能制造专项项目,超高频RFID室内定位天线设计(ZXD202218);东莞职业技术学院智能终端及智能制造专项项目,基于无线传感网络的桥梁健康监测系统研究(ZXB202201);东莞职业技术学院校级科研基金项目,基于遗传算法的多信道多点无线桥梁健康监测系统设计(2021c09)。

摘　　要：在室内环境中,由于建筑物的屏蔽效应、多径衰落等因素,会产生许多反射和散射的信号路径。这些多路径干扰会引入额外的相位差,并且当相邻标签或信号源之间的距离非常接近时,相位差可能超过一个波长,导致相位模糊现象的发生,无法准确获取不同载波信号源之间的相位差值,增加了定位难度。为了解决该问题,提出了基于超高频射频识别技术(UHF RFID)的室内定位方法。分析UHF RFID系统结构构成及工作原理。在UHF RFID标签读取器收到标签回复信号后,计算超高频载波信号相位角度;根据阅读器与标签间距离,提取出室内无源超高频信号相位,获取不同载波信号源的相位差;通过对相位差数据进行拟合分析,将相位差转化为欧式距离数据,解决相位差超过波长导致的相位模糊现象;对距离数据进行特征值分解,构建特征值的标量积矩阵,提取出标签回复的信号特征,并与其他信号源进行区分;结合已知的未知节点信息,通过相位差-多维标度定位算法进一步优化定位结果实现无源超高频定位。由实验结果可知:所提方法超高频信号相位差与实际值仅存在最大为0.01 rad的误差,最大定位误差仅为0.12 m,定位误差较小,在复杂的信道传播环境中依然能够保持较高的定位精度,定位效果较好。In indoor environments,due to factors such as shielding effects of buildings and multipath fading,there are many reflected and scattered signal paths.These multipath interferences introduce additional phase differences,and when the distance between adjacent labels or signal sources is very close,the phase difference may exceed one wavelength,leading to phase ambiguity and the inability to accurately obtain the phase difference between different carrier signal sources,increasing the difficulty of localization.To address this issue,an indoor positioning method based on ultra-high frequency radio frequency identification(UHF RFID) technology is proposed.Analyze the structure and working principle of UHF RFID system.After receiving the tag reply signal in the UHF RFID tag reader,calculate the phase angle of the ultra-high frequency carrier signal;Extract the phase of indoor passive ultra-high frequency signals based on the distance between the reader and the tag,and obtain the phase difference of different carrier signal sources;By fitting and analyzing the phase difference data,the phase difference is transformed into Euclidean distance data to solve the phase ambiguity phenomenon caused by the phase difference exceeding the wavelength;Perform eigenvalue decomposition on distance data,construct a scalar product matrix of eigenvalues,extract signal features of label replies,and distinguish them from other signal sources;By combining known unknown node information and using the phase difference multi-dimensional scaling positioning algorithm to further optimize the positioning results,passive ultra-high frequency positioning can be achieved.From the experimental results,it can be seen that the proposed method has a maximum error of 0.01 rad between the phase difference of the ultra-high frequency signal and the actual value,and a maximum positioning error of only 0.12m.The positioning error is relatively small,and it can still maintain high positioning accuracy in complex channel propagation environments,with good pos

关 键 词：UHF RFID 室内无源超高频 定位 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]