广义瞬时速度同步化分步解调变换及其对旋转机械振动信号分析  

A generalized instantaneous-frequency-estimation-free stepwise demodulation transform and its application in vibration signal analysis of rotating machinery

作　　者：石娟娟 花泽晖 沈长青 江星星 冯毅雄[2] 朱忠奎 孔林 SHI Juanjuan;HUA Zehui;SHEN Changqing;JIANG Xingxing;FENG Yixiong;ZHU Zhongkui;KONG Lin(School of Rail Transportation,Soochow University,Suzhou 215131,China;State Key Laboratory of Fluid Power and Mechatronic Systems,Zhejiang University,Hangzhou 310027,China;Chang Guang Satellite Technology Co.,Ltd.,Changchun 130102,China)

机构地区：[1]苏州大学轨道交通学院,江苏苏州215131 [2]浙江大学流体动力与机电系统国家重点实验室,杭州310027 [3]长光卫星技术有限公司,长春130102

出　　处：《振动与冲击》2021年第24期1-11,21,共12页Journal of Vibration and Shock

基　　金：中国博士后科学基金(2021M692353);苏州市重点产业技术创新项目(SYG202012);流体动力与机电系统国家重点实验室开放基金。

摘　　要：针对当前基于广义解调(generalized demodulation,GD)的方法对旋转机械振动信号处理的不足,提出了广义瞬时速度同步化分步解调变换。对信号进行短时截取,引入倾斜角对瞬时频率(instantaneous frequency,IF)进行描述,并采用峭度实现对倾斜角的自适应选取,从而获取该段信号的瞬时频率;而后推导前、后向解调因子对信号进行解调,避免了对瞬时频率进行预估计的同时提升了信号的时频可读性;进一步,针对多分量信号,通过对解调因子进行扩展,获取新的线性变换基函数,使所提方法在无需迭代下可同步增强多分量信号的时频表示;最后,对所提变换的信号重构进行了理论推导,证明了重构的可行性。通过仿真和旋转机械振动信号验证了所提方法在增强时频表示和提高特征提取准确性方面的有效性,与其他时频分析方法的对比也进一步体现了所提方法的优越性。Existing generalized demodulation(GD)based methods have inherent shortcomings for the vibration signal processing of rotating machinery.A generalized instantaneous frequency(IF)synchronized stepwise demodulation transform was proposed to address such shortcomings in this work.Firstly,the frequency of the truncated signal in a short time window can be treated as a straight line with an inclination angle.The angle determination strategy was proposed,where the appropriate angle can be selected by the guidance of the kurtosis index.Then,the novel forward and backward demodulators used in generalized demodulation can be used to demodulate the truncated signal.Through sliding the window,the time-frequency representation of the analyzed signal can be obtained with the boosted readability and independence of the instantaneous frequency pre-extraction.To effectively tackle multicomponent signals,the original linear transforming kernel was improved to enable the proposed method to simultaneously enhance the multiple frequency components without iterations.The signal reconstruction of the proposed transform was theoretically derived and the results show that the proposed method allows for the reconstruction of the interested frequency components.The simulation and experimental vibration signal analyses verify the effectiveness of the proposed method in enhancing the time-frequency representation and increasing the accuracy of the feature extraction.The comparison with other time-frequency analysis methods further indicates the advantages of the proposed method.

关 键 词：故障诊断 广义解调(GD) 时频分析 故障特征提取 变转速 

分 类 号：TH165.3[机械工程—机械制造及自动化] TN911.7[电子电信—通信与信息系统]