FDTD矿井无线传输特性分析方法研究  

Resarch on the FDTD analysis method of wireless transmission characteristics in underground mine

作　　者：张高敏 刘毅[1] 彭铭 ZHANG Gaomin;LIU Yi;PENG Ming(School of Mechanical Electronic&Information Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)机电与信息工程学院,北京100083

出　　处：《煤炭科学技术》2022年第11期202-212,共11页Coal Science and Technology

基　　金：国家重点研发计划资助项目(2016YFC0801800)。

摘　　要：为减少井下无线通信基站数量,提高井下无线信号覆盖范围和通信质量,需要研究无线通信基站天线和固定无线通信设备天线安装位置对矿井电磁波传播特性的影响。建立了由空气介质、巷道壁和完全匹配层组成的时域有限差分三维巷道模型,并根据该模型推导了时域有限差分迭代方程。提出了一种可变内阻激励源,以减小Yee网格间因感应电流引起的计算误差,并推导了该激励源的显式时域有限差分迭代方程,在巷道内测量了收发天线在巷道断面不同位置处的电磁波信号强度。结果表明:提出的可变内阻激励源计算出的电磁波信号强度仿真值与赫兹偶极子天线解析方程计算出的解析值在300 m自由空间内的衰减规律一致,性能优于透明激励源和硬激励源。激励源和接收点位于巷道断面中心时580、740、900 MHz三种频率电磁波信号强度的仿真值与测量值相比,衰减规律一致,表明提出的计算方法可用于研究巷道内电磁波传播特性。收发天线到同一巷帮等距时,两天线同步从巷道断面中心移动到巷帮附近,电磁波信号衰减逐渐增大;收发天线到巷帮距离在0~0.02 m范围内电磁波信号平均衰减梯度为217 dB/m,是0.04~0.30 m范围内的6.2倍,是0.02~0.04 m内的1.6倍。因此,在不影响行人和行车的条件下,无线通信基站天线应尽量远离巷帮,以获得最佳通信效果。In order to reduce the number of underground wireless communication base stations and increase the coverage and communication quality of wireless signals in underground mines, it is necessary to study the influence of the installation position of wireless communication base station antennas and fixed wireless communication equipment antennas on the propagation characteristics of the mine electromagnetic waves. A three-dimensional finite-difference time-domain tunnel model composed of air medium, tunnel walls and perfectly matched layers is established, and the iterative equation of finite-difference time-domain(FDTD) is derived based on the model. A variable internal resistance excitation source is proposed to decrease the calculation error caused by the induced current between Yee cells, and the explicit FDTD iterative equation of the excitation source is derived. The electromagnetic wave signal strength radiated by the transmitting antenna at different positions of the tunnel section was measured. The results show that the simulation value of electromagnetic wave signal strength calculated by the proposed variable internal resistance excitation source is consistent with the attenuation law of the analytical value calculated by the analytical equation of the Hertz dipole antenna in 300 m free space, and the performance of the excitation source is better than that of the transparent excitation source and the hard excitation source. When the excitation source and receiving point are located in the center of the tunnel section, the simulated signal strengths of 580, 740 and 900 MHz electromagnetic wave are consistent with the measured values, indicating that the proposed calculation method can be used to study the propagation characteristics of electromagnetic waves in the tunnel. When the transceiver antenna is equidistant from the same tunnel wall and the two antennas move synchronously from the center of the tunnel section to the vicinity of the tunnel wall, the attenuation intensity of the electromagnetic wave

关 键 词：矿井电磁波 无线传输特性 巷道模型 可变内阻激励源 天线位置 

分 类 号：TD65[矿业工程—矿山机电]