Improved DBO optimization VMD wavelet threshold vibration signal denoising method

In response to the issue of random interference in bearing vibration signals in noisy environments, an improved DBO optimized VMD wavelet threshold denoising method is proposed. The key to the variational mode decomposition (VMD) decomposition of rolling bearing signal lies in the choice of mode decomposition number and penalty factor of VMD. Therefore, before the decomposition of VMD, Dung Beetle Optimizer (DBO) with minimum envelope entropy as fitness function was used to optimize the parameters. Then, the optimal parameter combination is decomposed into VMD, and multiple modal components are obtained. The correlation coefficient between each modal component and the original signal after decomposition is calculated, and the leading noise component is denoised by wavelet threshold according to the correlation coefficient threshold. Finally, the processed IMF component and signal are reconstructed to obtain the signal after noise reduction. To validate the effectiveness of the proposed method, verification is conducted using both simulated and experimental signals, and comparisons are made with the VMD and wavelet denoising methods. The experimental results show that the signal-to-noise ratio, mean square error and correlation coefficient of the denoised signal are large. The research method has a certain reference value for noise reduction of rolling bearing vibration signal.