基于提升小波包最优基变换的缸盖振动信号降噪研究

Research on Cylinder Head Vibration Signal De-noising Based on Best Bases of Lifting Wavelet Package Transform

给出了一种基于提升小波包最优基变换的发动机缸盖振动信号降噪方法,给出了提升小波包变换公式,介绍基于最佳基分解的阈值降噪方法,并介绍了阈值的具体选择方法。将信号通过提升小波快速分解,对小波包系数进行阈值量化,用阈值量化后的系数对原信号重构,达到降噪的目的。通过计算仿真和实验,验证了方法的有效性。

A de-noising method for engine cylinder head vibration signal based on lifting wavelet package transform under the best base is proposed. The formulas of lifting wavelet package transform are presented. The threshold de-noising method based on best bases decomposing is introduced. And the means of selecting threshold is given. The signal is decomposed fast through lifting wavelet package transform. Coefficients of wavelet package are processed by the threshold. The original signal is reconstructed using the processed coefficients. So the purpose of de-noising is achieved. The effectiveness of the method is tested by computer simulating with an example.