Noise reduction method of plastic pipe leakage signal based on WOA-VMD algorithm

Aiming at the problem that it is difficult to select the appropriate number of decompositions K and penalty factor α for the denoising of plastic pipe leakage signal by variational modal decomposition (VMD) algorithm. In this paper, a noise reduction method based on Whale optimization algorithm (WOA) combined with VMD algorithm was proposed. First, the permutation entropy can reflect the complexity of the one-dimensional time series, and the decomposition result with the smallest permutation entropy is taken as the optimization objective; then the permutation entropy is used as a fitness function combined with WOA to optimize the parameters of the VMD algorithm to realize the adaptive decomposition of the leakage signal; Finally, calculate the correlation coefficient of each intrinsic mode function (IMF) component after decomposition to judge its noise level, remove the high frequency component which contains much noise, so as to realize the noise reduction of pipeline leakage signal. The simulate experimental results show that the method has a good denoising effect on the leakage signal of plastic pipeline, and can effectively improve the signal-to-noise ratio (SNR) of the leakage signal, which proves its feasibility in the actual leakage detection of plastic pipeline.