本文介绍无线射频识别技术(RFID)的基本原理,重点阐述基于RFID的LANDMARC定位算法的原理与过程。在此基础上,综合考虑铁路隧道内折射、反射、多径效应等因素对场强的影响,分析LANDMARC定位算法的不足,将此算法进行改进,提出自适应LANDMARC k-邻居算法,结合RF Code公司的硬件系统,将其应用到铁路隧道人员定位系统中。实验证明改进的算法具有更高的定位精度:定位精度在1m以内的标签占70%,比原来算法的60%提高10%;93%的标签定位误差小于1.5m,且最大误差控制在2.5m以内。对提高隧道内人员的安全管理水平具有重要意义。
The basic principle of radio frequency identification(RFID)technology was introduced.Great emphasis was placed on elaboration of the principle and process of the RFID based LANDMARC locating algorithm.Considering comprehensively the influence of refraction,reflection,multi-path effect and other factors in railway tunnels on the field strength and analyzing the shortcomings of the LANDMARC locating algorithm,the LANDMARC locating algorithm was improved and the adaptive LANDMARC k-nearest neighbor algorithm was proposed.The adaptive LANDMARC k-nearest neighbor algorithm was combined with the hardware of the RF Code Company and was applied in the railway tunnel personnel locating system.The experiment results show as follows:The improved algorithm can achieve better positioning accuracy;the tags with the positioning accuracy within 1 meter account for 70%,10%higher compared with the original algorithm;93% of positioning errors of tags are less than 1.5 meters and the maximum positioning error is kept within 2.5 meters;all these have great significance in improving the level of safety management of the personnel working inside a tunnel.