基于小波包的锅炉炉管声波信号自适应压缩感知  

Adaptive compressed sensing of boiler tube acoustic signals based on wavelet packet

作　　者：杨正理[1] 史文 陈海霞[1] YANG Zhengli;SHI Wen;CHEN Haixia(School of Mechanical and Electrical Engineering,Sanjiang University,Nanjing 210012,China)

机构地区：[1]三江学院机械与电气工程学院,江苏南京210012

出　　处：《热力发电》2019年第5期114-120,共7页Thermal Power Generation

基　　金：江苏省高校自然科学研究面上项目(17KJB470011)~~

摘　　要：在锅炉炉管泄漏声波自动报警系统中,针对声波信号在采集、传输、处理与存储过程中存在数据规模大、传输带宽高和所需存储量大等问题,提出基于小波包的锅炉炉管声波信号自适应压缩感知方法。首先采用小波包分析方法对炉管声波信号进行多尺度分解,计算各尺度下小波包系数的数学期望,并将其作为阈值,对小波包系数进行置零处理,根据各分解尺度下的稀疏度自适应地选择最优小波包分解层数;然后对最优分解层数下的各小波包系数块按照其数学期望和信息熵进行分类,并对分类后的各小波包系数块采用不同方法进行处理。实际应用结果表明,本文方法有效减少了炉管声波信号的观察数据,提高了信号压缩率,并在相同观察次数下,降低了信号的传输带宽和存储容量,提高了信号的处理速度和重构精度。In the automatic alarm system for leakage of boiler tubes based on acoustic signals, to solve the problems of large data size, high transmission bandwidth and large storage occurred during the acquisition, transmission, processing and storage of acoustic signals, an adaptive compressed sensing method for the boiler tube acoustic signals based on wavelet packet is proposed. Firstly, the wavelet packet analysis method is used to decompose the acoustic signals of the boiler tube in multiple scales, and the mathematical expectation of the wavelet packet coefficient under each scale is calculated as the threshold value. The wavelet packet coefficient is zero processed, and the optimal wavelet packet decomposition layer number is selected adaptively according to the sparse degree values under each decomposition scale. Then, each wavelet packet coefficient block under the optimal decomposition layer is classified according to its mathematical expectation and information entropy, and each wavelet packet coefficient block after classification is processed by different methods. The method in this paper is applied to the historical data of the acoustic wave automatic alarm system of a boiler tube, the results show that, the proposed method can effectively reduce the observed data of acoustic signals in furnace tubes, increase the signal compression rate, reduce the transmission bandwidth and storage capacity of signals at the same observation times, and improve the processing speed and reconstruction accuracy of signals.

关 键 词：锅炉 炉管 声波信号 信号压缩 小波包分析 压缩感知 数学期望 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]