基于非视距误差抑制的矿井轨道机车定位方法研究

Research on positioning method of mine track locomotives based on not line of sight error suppression

  • 摘要: 矿井轨道机车定位方法以超宽带(UWB)定位为主,但井下运输巷道环境复杂,非视距传播多发,对UWB定位精度的影响严重。目前针对非视距传播引起的定位误差研究存在算法复杂、实时定位差等问题。通过分析轨道机车定位特点,在基于信号到达时间(TOA)的UWB定位技术基础上,提出一种基于非视距误差抑制的矿井轨道机车定位方法。在轨道机车不同位置安装2个定位卡,采用射频识别技术准确划分定位卡与定位基站的相对位置关系,根据UWB定位信号在非视距传播条件下测距值比实际值大的情况,采用2个定位卡之间距离测算值与实际值差值的经验范围,推算出不同定位卡和定位基站位置关系下非视距传播条件的鉴别阈值,通过该鉴别阈值剔除由非视距路径传播定位信号的测距值,使用由视距路径传播定位信号的测距值进行定位计算,实现对非视距误差的抑制,从而提高矿井轨道机车平均定位精度。测试结果表明:使用基于非视距误差抑制的矿井轨道机车定位方法,在定位信号处于视距传播条件时,机车平均定位误差均在1 m以内;在定位信号处于非视距传播条件时,大部分非视距误差得到了有效抑制,平均定位精度在1 m左右,轨道机车定位精度较常规基于TOA的UWB定位方法大幅度提升。

     

    Abstract: The positioning method for mine track locomotives is mainly based on ultra wide band (UWB) positioning. But the complex environment of underground transportation roadways and frequent not line of sight(NLOS) propagation seriously impact the precision of UWB positioning. At present, research on positioning errors caused by NLOS has problems such as complex algorithms and poor real-time positioning. Based on the analysis of the positioning characteristics of railway locomotives and the UWB positioning technology based on the time of arrival (TOA), a positioning method of mine track locomotive based on NLOS error suppression is proposed. Two positioning cards are installed at different positions on the track locomotive. Radio frequency identification technology is used to accurately divide the relative position relationship between the positioning card and the positioning base station. The distance measurement value of the UWB positioning signal is greater than the actual value under NLOS propagation conditions. Based on this situation, the empirical range of the difference between the distance measurement value and the actual value between the two positioning cards is used to calculate the discrimination threshold for NLOS propagation conditions under different position nelationship between positioning cards and positioning base station. By using this discrimination threshold, the ranging value of the positioning signal propagated by NLOS path is eliminated. The ranging value of the positioning signal propagated by the line of sight path is used for positioning calculation, so that to suppress NLOS errors and improve the average positioning precision of mine track locomotives. The test results show that using the positioning method of mine track locomotives based on NLOS error suppression, the average positioning error of locomotives is within 1 m when the positioning signal is in line of sight propagation conditions. When the positioning signal is in NLOS propagation conditions, most of the NLOS errors are effectively suppressed. The average positioning precision is about 1 meter. The positioning precision of track locomotives has been greatly improved compared with normal UWB positioning method based on TOA.

     

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