井下移动目标无线定位技术研究

发布时间：2018-03-01 16:21

本文关键词： 智能天线解相干DOA估计最大似然估计TOA估计角度变化率 Chan算法　出处：《中国矿业大学》2014年硕士论文　论文类型：学位论文

【摘要】：由于很多无线通信技术（如WCDMA、WIFI、ZIGBEE、蓝牙等）受到井下巷道和工作面复杂多变环境的影响，通信性能较差，导致井下移动目标无线定位效果并不理想。为了解决井下多径和非视距效应造成的无线网络稳定可靠性较差问题，本文将智能天线原理和WIFI通信网络相结合，以智能天线接收机作为井下WIFI基站，可有效抑制巷道多径和非视距效应对信号传播的影响，提高DOA和TOA估计精度。同时，从理论上分析相关的DOA和TOA估计技术，并有针对性的探讨和构建了井下无线定位相关理论模型和相关井下无线定位算法，其具体研究内容如下： 1．针对不同的巷道和工作面，分析信号传播路径衰减及其反射形式，建立覆盖整个井下的无线网络基站分布模型，并在此基础上构建了基于DOA和TOA的联合定位模型。 2．针对井下有限异质可变空间导致产生的相干信源干扰，重点分析基于解相干的DOA估计技术，分别采用前向平滑、前后向平滑和Toeplitz算法进行解相干处理，获得高精度的DOA估计信息，并通过仿真分析表明：在井下相干信源干扰的DOA估计中，Toeplitz算法相比其他解相干技术具有更好的估计性能。 3．由于受到井下多径、非视距和网络时间同步的影响，导致到达时间延迟估计偏差较大，提出了一种最大似然TOA估计的迭代算法，通过将小数延时不断迭代来缩小估计误差，并做出仿真表明：采用50步长搜索，且进行一次迭代就可得到较高精度的TOA估计信息。 4．为了消除DOA和TOA测距误差，根据基本单站定位原理，分别提出了基于角度变化率和单次反射的定位方法，并仿真分析了他们之间的定位性能。针对井下网络时间同步带来的TOA测距误差影响，根据多基站定位原理，，分别提出了改进的Chan算法和加权修正的定位算法，仿真表明，改进的Chan算法相比其他算法具有更高的定位效果，并且应选择距离移动节点较近且估计精度较高的基站联合定位。
[Abstract]:Because many wireless communication technologies (such as WCDMA-WIFIZIGBEE, Bluetooth, etc.) are affected by the complex and changeable environment of underground roadway and working face, the communication performance is poor. In order to solve the problem of poor stability and reliability of wireless network caused by multi-path and non-line-of-sight effect, the principle of smart antenna and WIFI communication network are combined in this paper. Using the smart antenna receiver as the downhole WIFI base station can effectively suppress the influence of multi-path and non-line-of-sight effect on the signal propagation and improve the accuracy of DOA and TOA estimation. At the same time, the related DOA and TOA estimation techniques are analyzed theoretically. And the relevant theoretical model of underground wireless location and related underground wireless positioning algorithm are discussed and constructed. The specific research contents are as follows:. 1. For different roadways and working faces, the attenuation of signal propagation path and its reflection form are analyzed, and the distribution model of wireless network base station covering the whole mine is established, and the joint positioning model based on DOA and TOA is constructed. 2. Aiming at the interference of coherent source caused by the limited heterogeneity variable space, the DOA estimation technology based on decoherence is analyzed, and the forward smoothing, forward smoothing and Toeplitz algorithm are used to decolonize respectively. The DOA estimation information with high accuracy is obtained, and the simulation results show that the Toeplitz algorithm has better estimation performance than other decoherence techniques in the DOA estimation of coherent source interference. 3. Due to the influence of underground multipath, non-line-of-sight and network time synchronization, the error of arrival time delay estimation is large. An iterative algorithm of maximum likelihood TOA estimation is proposed, which reduces the estimation error by iterating the fractional delay. The simulation results show that the TOA estimation information with high accuracy can be obtained by using 50 step search and one iteration. 4. In order to eliminate the errors of DOA and TOA ranging, according to the basic principle of single-station positioning, the localization methods based on the rate of angular variation and single reflection are proposed, respectively. According to the location principle of multi-base station, the improved Chan algorithm and the weighted modified location algorithm are proposed, and the simulation results show that, according to the influence of the time synchronization of downhole network on the location error of TOA, an improved Chan algorithm and a weighted modified location algorithm are proposed, and the simulation results show that, The improved Chan algorithm has higher localization effect than other algorithms, and the base station which is close to the mobile node and has higher estimation accuracy should be selected.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.5

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