一种新的摆度信号去噪方法及其应用

A New Method of De-noising of Pendulum Signal and Its Application

受现场环境和设备的干扰,水轮机组摆度信号中存在较强的脉冲噪声和高斯白噪声,导致真实有效信号被淹没,这为信号提取带来很大的困难。针对这一问题,提出一种将中值滤波、小波阈值去噪以及Savitzky-Golay平滑滤波相结合的摆度信号去噪方法。首先,对待分析信号用中值滤波器进行去除脉冲噪声的预处理;其次,通过Savitzky-Golay平滑滤波和阈值去噪分别去除小波分解后的近似系数和细节系数中的白噪声分量。仿真结果表明,该方法能有效提高信噪比、局部相关指数以及平滑度,降低均方误差。实验结果表明,该方法既能去除水轮机组摆度信号中的噪声,又能有效保留真实信号中的细节特征。

The swing signal of the hydraulic turbine unit includes strong impulse noise and Gauss white noise due to the disturbance of the field environment and equipment.This results in the real effective signal being submerged which brings great difficulty for signal extraction.In the light of this problem,a swing signal denoising method that combines median filtering,wavelet threshold de-noising and SavitzkyGolay smoothing filter is proposed.First,the median filter is used to remove the impulse noise in the analysis signal.Then,the Savitzky-Golay smoothing filter and threshold denoising are used to remove the white noise components in approximate coefficient and detail coefficient after wavelet decomposition respectively.The simulation results show that the method can effectively increase the signal-to-noise ratio(SNR),local correlation index(LCI)and smoothness(S),and reduce the mean square error(MSE).The experimental results show that the method can not only remove the noise in the swing signal of the water turbine,but also effectively retain the details of the real signal.