调频率自适应匹配线性变换及其对旋转机械故障诊断研究  

Adaptively matching chirp-rate linear transform and its application to fault diagnosis of rotating machinery

作　　者：花泽晖 石娟娟 王艳芳[2] 江星星 沈长青 朱忠奎 HUA Ze-hui;SHI Juan-juan;WANG Yan-fang;JIANG Xing-xing;SHEN Chang-qing;ZHU Zhong-kui(School of Rail Transportation,Soochow University,Suzhou 215131,China;Department of Automobile Engineering,Zhengzhou Technical College,Zhengzhou 450121,China)

机构地区：[1]苏州大学轨道交通学院,江苏苏州215131 [2]郑州职业技术学院汽车工程系,河南郑州450121

出　　处：《振动工程学报》2021年第5期1053-1063,共11页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(51875376,51705349);中国博士后科学基金资助项目(2021M692353)。

摘　　要：旋转机械常处于变转速工作状态,因而其振动信号也表现出非平稳性。分析此类非平稳信号时由于受有限的时频分辨率影响,常无法获得理想的时频表示,难以揭示与旋转机械健康状态相关的有用信息。根据单个线性调频变换(LCT)能提升特定时刻时频聚集性这一特点,提出了调频率自适应匹配线性变换(Adaptively Matching Chirp-rate Linear Transform,AMCLT)。利用最大峭度准则指导选取每个时刻合适的调频率,并且只保留与所选调频率相关的时频分布用于构造最终的时频表示;扩展原始线性变换基函数,使所提AMCLT方法在无需迭代情况下可同时完成对多分量非线性调频信号的分析。此外,对所提AMCLT方法进行了信号重构分析,可实现对信号中目标频率分量的时域信号重构。振动信号处理结果表明,在时频表示的可读性方面,所提方法可得到能量更加集中且不受交叉项干扰的时频表示;在特征提取方面,所提方法可更加准确地提取旋转机械振动信号中的频率特征,可有效应用于旋转机械的故障诊断。Rotating machinery usually works in the time-varying speed condition so that the vibration signal which contains rich health information also shows strong non-stationarities.Constrained by limited time-frequency(TF)resolution,the ideal time-frequency representation(TFR)cannot be obtained when the frequency of the analyzed signal varies.Based on the fact that a single linear chirplet transform can improve the concentration level of the TFR when the slope of the frequency is consistent with the chosen chirp-rate in LCT,a new time-frequency analysis(TFA)method is proposed,named as adaptively matching chirp-rate linear transform(AMCLT).To better match the changing frequency of the signal,chirp-rate determination strategy guided by kurtosis is proposed.To simplify the algorithm,the original linear transform kernel is advanced to make the proposed method increase the TFR concentration level when analyzing multiple frequency-modulated signals without iterations.Besides,the proposed method also allows for the perfect signal reconstruction of the interested frequency components.The analyzing results of vibration signal shows that,in terms of readability of the TFR,the proposed method can acquire the improved TFR with more concentrated energy and free from cross term interference.In terms of the feature extraction,the proposed method can extract the fault related features in the rotating machinery vibration signal more accurately and can be effectively applied to fault diagnosis of rotating machinery.

关 键 词：故障诊断 轴承 变转速工况 时频分析 线性调频变换 峭度 

分 类 号：TH165.3[机械工程—机械制造及自动化] TH133.3