【摘要】：小波閾值降噪是近年來水電機(jī)組狀態(tài)監(jiān)測信號去噪常用的算法,經(jīng)典的閾值函數(shù)為硬、軟閾值兩種函數(shù)。在硬閾值方法中,處理過的小波系數(shù)在閾值處是間斷的,得到的估計(jì)信號在重構(gòu)時易產(chǎn)生局部附加振蕩;而經(jīng)軟閾值函數(shù)降噪的信號雖然整體連續(xù)性好,但與原始信號之間總是存在著恒定的偏差,影響重構(gòu)精度。因此在軟、硬閾值函數(shù)基礎(chǔ)上提出了一種改進(jìn)閾值函數(shù)的小波降噪算法,通過Matlab仿真和實(shí)際采集數(shù)據(jù)的實(shí)驗(yàn)結(jié)果表明:該方法克服了傳統(tǒng)軟、硬閾值函數(shù)算法的缺點(diǎn),不僅連續(xù)性好,而且提高了信噪比。通過對比降噪后對振動信號特征能量的保留程度,說明改進(jìn)閾值函數(shù)較傳統(tǒng)經(jīng)典去噪方法更為優(yōu)越,是一種有效的降噪方法。
[Abstract]:Wavelet threshold de-noising is a commonly used algorithm for de-noising of state monitoring signals of hydropower units in recent years. The classical threshold functions are hard and soft threshold functions. In the hard threshold method, the processed wavelet coefficients are discontinuous at the threshold, and the estimated signals are prone to produce local additional oscillations during reconstruction. Although the signal denoised by soft threshold function has good overall continuity, there is always a constant deviation between the signal and the original signal, which affects the reconstruction accuracy. Therefore, a wavelet denoising algorithm based on soft and hard threshold functions is proposed. The results of Matlab simulation and actual data acquisition show that the method overcomes the shortcomings of the traditional soft and hard threshold function algorithms. Not only the continuity is good, but also the signal-to-noise ratio is improved. By comparing the reserve degree of characteristic energy of vibration signal after noise reduction, it is proved that the improved threshold function is more superior than the traditional classical denoising method, and it is an effective denoising method.
【作者單位】： 武漢大學(xué)動力與機(jī)械學(xué)院水電站過渡過程教育部重點(diǎn)實(shí)驗(yàn)室;
【基金】：國家自然科學(xué)基金項(xiàng)目(51379160)
【分類號】：TV734

【參考文獻(xiàn)】

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1 唐友懷;張海濤;羅珊;姜U，

本文編號：2370494