Spectral Graph Wavelet Threshold Denoising and Its Application to Vibration Signal Analysis for Hob Spindle

By analyzing the application of spectral graph wavelet transform in plane image and three-dimensional solid analysis, a spectral graph wavelet threshold denoising method is proposed for one-dimensional digital signal analysis. In this method, the one-dimensional digital signal is defined on the path graph, which is decomposed into scale coefficients and spectral graph wavelet coefficients by spectral graph wavelet transform, and the spectral graph wavelet coefficients are filtered by threshold. Thus the denoising signal is obtained by spectral graph wavelet inverse transform. Firstly, four typical simulation signals are used for denoising test, and the influence of different decomposition layers on denoising performance is analyzed. Then, the performance of the proposed method is compared with that of the classical wavelet threshold denoising method by simulation. Finally, the method is applied to the denoising experiment of hob spindle vibration signal, and compared with the classical wavelet threshold denoising method. Simulation and experimental results show that the proposed method can realize the fast non-iterative denoising of one-dimensional digital signal, and the denoising signal has high smoothness and small distortion. Also, it is obviously superior to the classical wavelet threshold denoising method.