基于小波分形的旋转机械声发射信号的故障诊断研究  

Research on Fault Diagnosis in Rotary Machinery Acoustic Emission Signal Based on Wavelet Fractal

作　　者：张瑞[1] 邓艾东[1] 司晓东 刘振元 刘东瀛[1] 李晶[4] 黄宏伟 

机构地区：[1]东南大学火电机组振动国家工程研究中心,南京210096 [2]东南大学能源与环境学院,南京210096 [3]宁波市自来水有限公司,宁波315041 [4]东南大学信息科学与工程学院,南京210096 [5]国电投河南电力有限公司技术信息中心,郑州450001

出　　处：《汽轮机技术》2017年第2期151-155,共5页Turbine Technology

基　　金：国家工程中心创新能力建设项目(6750100000)

摘　　要：碰摩是旋转机械运行中的常见故障,对碰摩故障进行及时预警对于保障机组安全具有重要的意义。提出了一种基于小波变换的分形分析方法进行碰摩识别,将声发射碰摩信号分解成不同的频带,计算其方差,最后得到小波分形维数。在转子实验台上分别测得无碰摩、轻微碰摩和严重碰摩3种状态下的声发射信号并进行分析,计算声发射信号的小波分形维数,然后根据分形维数的变化对碰摩状态进行判别。同时对该方法和传统的G-P算法计算出的分形维数进行比较。实验结果表明,分形方法能有效判别碰摩的发生,该方法较G-P算法对碰摩发生的区分度更好。本方法为旋转机械碰摩故障的诊断提供了一条新的途径。Rub-impact is a common fault in rotating machinery operation. It will be of great significant to warn the rub- impact fault for protecting the safety of unit. In this work, a wavelet fractal method is proposed to identify the rub-impact. The signal of acoustic emission rub-impact can be decomposed into different frequency bands by using wavelet transform and then calculate the variance of each frequency band individually; finally the fractal dimension is acquired. The acoustic emission rub-impact signal is characterized by conditions of no rub-impact, slight rub-impact and heavy rub-impact. Analysis the acoustic emission signal under conditions of no rub-impact, slight rub-impact and heavy rub-impact, calculate the wavelet fractal dimension of the acoustic emission rub-impact signal, and then distinguish the condition of rub-impact based on the change of the fractal dimension. By comparing this method with G - P algorithm, it can be concluded that the fractal method can effectively distinguish the happening of the rub-impact and thus this method provides a new way in the fault diagnosis for rotating machinery.

关 键 词：小波分形 声发射 碰摩 关联维数 

分 类 号：TH165[机械工程—机械制造及自动化]