针对现有基于无源LANDMARC算法的改进研究主要以提高定位精度为目标,并没有考虑无源半双工通信机制引起的标签读取耗时较长的问题,引入路径损耗公式推导出基于辐射半径的功率能级映射模型.通过分析阅读器最大功率能级、参考标签布设密度对定位精度及系统耗时的影响,结合多目标优化的联合控制机制,提出一种适用于无源LANDMARC算法的定位性能评价方法.多种环境下的仿真结果表明,所提评价方法具有良好的稳定性和实用性,对于无源RFID定位系统的参数选择及性能评定具有一定的实际意义.
Considering most advanced LANDMARC algorithms based on passive RFID mainly aimed at enhancing the accuracy of the localization but neglecting the long time consumed in reading tags because of the by half-duplex mechanism, we leverage the distance loss formula and put forward power level model based on the radiation radius. After analyzing the influences of the maximum power grades of the RF reader and the arrangement density of the reference tags, an evaluation method of localization is proposed for the passive LANDMARC algorithm. Simulation results in a wide range of environments showed that the proposed method has the good stability and practicability. The method also makes sense of system evaluation and parameter selection for the passive RFID Localization Algorithms.