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针对小波分析在机械故障诊断应用中的小波基选择和快速算法存在的问题 ,对常用的正交、半正交、双正交小波提取信号特征的能力进行了分析比较 ,表明半正交 B样条小波因具有线性相位和采用较长的分解序列而具有较好的频率局部化特性和较小的变换误差 ,具有比较好的综合性能。推导了正交小波包的图形显示算法 ,利用该算法解决了小波变换快速算法中存在的数据长度随分解层数成倍减小的问题。研究结果为故障诊断中小波基的选择和信号的深层次处理提供了依据和途径
Aiming at the existing problems of wavelet base selection and fast algorithm in the application of mechanical fault diagnosis based on wavelet analysis, the ability of commonly used orthogonal, semi-orthogonal and biorthogonal wavelet to extract signal features are analyzed and compared. It shows that semi-orthogonal B-like Because of the linear phase and the use of a longer decomposition sequence of the wavelet has better frequency localization and smaller transform error, with better overall performance. The algorithm of graph display of orthogonal wavelet packet is deduced. The algorithm solves the problem that the length of data in DWT algorithm decreases with the number of decomposition layers. The results provide the basis and approach for the selection of wavelet bases and deep processing of signals in fault diagnosis