CAJ | 학술논문

齿轮故障振动信号往往表现为非线性非平稳特性，并且早期故障振动信号往往包含较强的背景噪声，不利于故障特征的提取。针对该问题，提出了基于双树复小波变换和局部投影算法的齿轮故障诊断方法。首先，对故障信号进行双树复小波变换，得到不同尺度下的小波系数和最后一层的尺度系数，并计算各层小波系数的模与相角。然后，选择模周期性较强的小波系数或尺度系数进行局部投影算法处理，得到周期性增强的系数的模，并选择合适的阈值进行软阈值处理。最后，利用处理后的系数进行双树复小波重构，从而提取出齿轮故障特征信号，进行希尔伯特包络解调分析便能准确地得到故障特征频率。仿真信号和工程应用表明，该方法能够有效地提取齿轮故障特征信息，提供了一种齿轮故障特征提取的新方法。
치륜고장진동신호왕왕표현위비선성비평은특성，병차조기고장진동신호왕왕포함교강적배경조성，불리우고장특정적제취。침대해문제，제출료기우쌍수복소파변환화국부투영산법적치륜고장진단방법。수선，대고장신호진행쌍수복소파변환，득도불동척도하적소파계수화최후일층적척도계수，병계산각층소파계수적모여상각。연후，선택모주기성교강적소파계수혹척도계수진행국부투영산법처리，득도주기성증강적계수적모，병선택합괄적역치진행연역치처리。최후，이용처리후적계수진행쌍수복소파중구，종이제취출치륜고장특정신호，진행희이백특포락해조분석편능준학지득도고장특정빈솔。방진신호화공정응용표명，해방법능구유효지제취치륜고장특정신식，제공료일충치륜고장특정제취적신방법。
As gear fault vibration signal is always nonlinear and nonstationary and always with a strong background noise which result in difficulty of fault feature extraction ,a new method based on dual‐tree complex wavelet transform and local projective method is proposed .As a improved method of the conventional discrete wavelet transform (DWT ) ,dual‐tree complex wavelet transform has many advantages over DWT ,such as the improvement of frequency aliasing and oscillations of wavelet coeffi‐cients which is the key to the method proposed .Local projective method for nonlinear time series has a good ability of signal period strengthen and noise suppression ,which fits for wavelet coefficients denoising .Firstly ,the fault signal is decomposed by dual‐tree complex wavelet transform to obtain the coefficients of different layers .Secondly ,the nonlinear time series method is used to strengthen the periodicity of the coefficient whose amplitude is more periodic ,and then do soft‐threshold denoising . Finally ,the fault characteristic signal can be obtained by coefficient reconstruction .The fault frequency can be located accurate‐ly by Hilbert envelope spectrum analysis .The simulation and engineering application showed the effectiveness of the method in early gear fault diagnose .