基于小波变换的多路基坑尺寸检测降噪评估  

Noise reduction evaluation of multi-channel foundation pit size detection based on wavelet transform

作　　者：张周 胡科 张鹏 林佳 胡涤尘 ZHANG Zhou;HU Ke;ZHANG Peng;LIN Jia;HU Dichen(State Grid Hubei Power Transmission and Transformation Engineering Co.,Ltd.,Wuhan 430000 Hubei,China;State Grid Electric Power Research Institute Wuhan Nanrui Co.,Ltd.,Wuhan 430070 Hubei,China)

机构地区：[1]国网湖北送变电工程有限公司,湖北式汉430000 [2]国网电科院武汉南瑞有限责任公司,湖北武汉430070

出　　处：《电力大数据》2020年第8期9-17,共9页Power Systems and Big Data

摘　　要：为提高超声波用于基坑尺寸测量的精度,本文基于超声波传播特性,分析环境中压强、湿度、温度噪声的影响,仿真设计多路理想回波信号模拟超声波测距用于基坑检测的场景,加入不同强度的白噪声模拟环境中噪声干扰,基于小波变换对加噪信号进行处理,研究不同小波基、分解层数、阂值处理函数等核心参数对重构后信号的影响,引入信噪比、均方根误差、决定系数评估降噪效果。实验结果表明,当超声波用于基坑尺寸检测时,压强、湿度、温度对超声波传播的影响可以忽略不计,环境噪声干扰以高斯白噪声为主,当多路回波信号混入不同强度的白噪声时,不同小波参数重构的信号降噪效果不同,选用db8小波基、4层分解层数、硬阈值处理函数可以达到较好的降噪效果。In order to improve the accuracy of ultrasonie measurement for the size of foundation pits,this paper analyzes the influence of pressure,humidity,and temperature noise in the environment based on the characteristics of ultrasonic propagation,simulates and designs multiple ideal echo signals to simulate ultrasonic ranging for foundation pit detection,white noise of different intensities is added to simulale the noise interference in the environment,the noise signal is processed based on wavelet transform,and the influence of core parameters such as different wavelet bases,decomposition layers,and threshold processing functions on the reconstructed signal is studied,the signal to noise ratio,root mean square eror and cofficient of determination evaluate the effect of noise reduction.The experimental results show that when ulrasonic waves are used for pit size detection,the infuence of pressure,humidity,and temperature on ultrasonic propagation is negligible,the environmental noise interferenee is dominated by gaussian white noise,when the multiple ccho signals are mixed with white noise of different intensities,the signal denoising effect of different wavelet parameter reconstruction is different,choosing the db8 wavelet base,4-layer decomposition layer,and hard threshold processing function can achieve better denoiaing efeet.

关 键 词：超声波测距 小波变换 回波信号 重构信号 降噪效果 

分 类 号：TM75[电气工程—电力系统及自动化]