基于小波阈值函数降噪的实时煤矿氧气检测数据误差处理  

Error Processing of Real-time Coal Mine Oxygen Detection Data Based on Wavelet Threshold Function Denoising

作　　者：张华乾 于庆[1,2,3] ZHANG Huaqian;YU Qing(CCTEG Chinese Institute of Coal Science,Beijing 100013,China;CCTEG Chongqing Research Institute,Chongqing 400037,China;State Key Laboratory for Coal Mine Disaster Preventing and Control,Chongqing 400037,China)

机构地区：[1]煤炭科学研究总院,北京100013 [2]中煤科工集团重庆研究院有限公司,重庆400037 [3]煤矿灾害防控全国重点实验室,重庆400037

出　　处：《煤矿机电》2023年第6期28-32,37,共6页Colliery Mechanical & Electrical Technology

基　　金：新疆矿山安全监测预警和应急管理平台研发与示范项目(2022B03031);中国煤炭科工集团科技创新创业资金专项重点项目(2023-TD-ZD005-002);中煤科工集团重点项目重庆研究院有限公司重点科研项目(2023ZDYF03)。

摘　　要：基于可调谐半导体激光吸收光谱(Tunable Diode Laser Absorption Spectroscopy,TDLAS)技术的氧气检测系统能够精准检测煤矿井下环境的氧气体积分数,然而应用该系统检测氧气体积分数时往往会受到散粒噪声、热噪声、高斯白噪声等噪声信号的影响,导致氧气体积分数检测误差较大。为了降低噪声对氧气体积分数检测数据的影响,首先,应用多项式平滑算法对氧气体积分数检测曲线进行高低频分析。其次,提出了基于小波阈值函数降噪的煤矿氧气检测数据误差处理方法,对比了Daubechies小波和Symlets小波的降噪效果,根据信噪比和均方根误差选出最佳降噪小波基函数。最后,通过计算氧气体积分数检测曲线的标准差和最大波幅对比降噪前后氧气体积分数检测的稳定性。试验结果表明:sym6小波基函数与二次谐波信号相关程度最大,应用该小波对二次谐波信号进行降噪,信噪比提升了16.785 dB,降噪前后20%氧气体积分数检测曲线最大幅值降低了0.04%,标准差降低了0.0295,显著提升了氧气体积分数检测稳定性。The oxygen detection system based on Tunable Diode Laser Absorption Spectroscopy(TDLAS)technology can accurately detect the oxygen volume fraction in the underground environment of coal mines.However,when using this system to detect oxygen volume fraction,it is often affected by noise signals such as shot noise,thermal noise,and Gaussian white noise,resulting in significant errors in oxygen volume fraction detection.In order to reduce the impact of noise on oxygen volume fraction detection data,firstly,polynomial smoothing algorithm was applied to perform high and low frequency analysis on the oxygen volume fraction detection curve.Secondly,a method for processing errors in coal mine oxygen detection data based on wavelet threshold function denoising was proposed.The denoising effects of Daubechies wavelet and Symlets wavelet were compared,and the best denoising wavelet basis function was selected based on signal-to-noise ratio and root mean square error.Finally,the stability of oxygen volume fraction detection before and after noise reduction was compared by calculating the standard deviation and maximum amplitude of the oxygen volume fraction detection curve.The experimental results showed that the sym6 wavelet basis function had the greatest correlation with the second harmonic signal.Applying this wavelet to denoise the second harmonic signal improved the signal-to-noise ratio by 16.785dB.Before and after denoising,the maximum amplitude of the 20%oxygen volume fraction detection curve decreased by 0.04%,and the standard deviation decreased by 0.0295,significantly improving the stability of oxygen volume fraction detection.

关 键 词：可调谐半导体激光吸收光谱 小波阈值函数降噪 高低频分析 氧气检测精度 

分 类 号：TN911.7[电子电信—通信与信息系统]