CAJ | 학술논문

经验小波变换(EWT)是一种新的自适应信号分解方法，该方法继承了 EMD 和小波分析方法的各自优点，通过提取频域极大值点自适应地分割傅里叶频谱以分离不同的模态，然后在频域自适应地构造带通滤波器组从而构造正交小波函数，以提取具有紧支撑傅立叶频谱的调幅-调频(AM-FM)成分。本文将该方法引用到机械故障诊断中，提出了一种基于经验小波变换的机械故障诊断方法，并与EMD方法进行了对比分析。仿真结果表明，经验小波变换方法明显优于EMD方法，能有效地分解出信号的固有模态。与 EMD 相比较，该方法具有分解的模态少，不存在虚假的模态，计算量小，且在理论上具有易理解性等特点。最后将该方法应用到转子碰磨故障诊断中，实验结果进一步验证了该方法的有效性，能够有效地揭示出碰磨故障数据的频率结构，区分碰磨故障的严重程度。
경험소파변환(EWT)시일충신적자괄응신호분해방법，해방법계승료 EMD 화소파분석방법적각자우점，통과제취빈역겁대치점자괄응지분할부리협빈보이분리불동적모태，연후재빈역자괄응지구조대통려파기조종이구조정교소파함수，이제취구유긴지탱부립협빈보적조폭-조빈(AM-FM)성분。본문장해방법인용도궤계고장진단중，제출료일충기우경험소파변환적궤계고장진단방법，병여EMD방법진행료대비분석。방진결과표명，경험소파변환방법명현우우EMD방법，능유효지분해출신호적고유모태。여 EMD 상비교，해방법구유분해적모태소，불존재허가적모태，계산량소，차재이론상구유역리해성등특점。최후장해방법응용도전자팽마고장진단중，실험결과진일보험증료해방법적유효성，능구유효지게시출팽마고장수거적빈솔결구，구분팽마고장적엄중정도。
Empirical wavelet transform (EWT) is a new self adaptive signal decomposition method. This method inherits the ad-vantages of EMD and wavelet transform, adaptively segments the Fourier spectrum by extracting the maxima point in the frequen-cy domain to separate the different modes, and then constructs adaptive band-pass filters in the frequency domain so as to construct orthogonal wavelet functions and extract AM-FM components that have a compact support Fourier spectrum. Here, the EWT is introduced in the mechanical fault diagnosis, and a new mechanical fault diagnosis method based on EWT is proposed. The EWT method is compared with the traditional EMD method. The simulation results show that the EWT method is obviously superior to the EMD method. The proposed method can effectively decompose the intrinsic modes of the signal. Compared with the EMD method, this method has some distinct advantages, such as less decomposed modes, no virtual modes, less calculation, easy to be understood in theory and etc. Finally, the proposed method was successfully applied to the rub-impact fault diagnosis of a rotor system. The experiment results show that the proposed method is effective, and can effectively reveal the frequency structure in rubbing fault and discern the severity of rub-impact fault.