An Effective Method on Reducing Measurement Noise Based on Hilbert-Huang Transform
نویسندگان
چکیده
For non-stationary signal in ultrasonic inspection, an effective denoising method based on Hilbert-Huang transform (HHT) is presented and a few key questions using the HHT method are discussed. The overall scheme of HHT includes two parts which are empirical mode decomposition (EMD) algorithm and a sum of intrinsic mode functions (IMF). Through the EMD process, individual IMF can be found. The IMF coefficients are preceded in useful signal dominative layers using a soft threshold method and finally those IMF coefficients are reconstructed. The results show that the usage of HHT method is reasonable at removing the measurement noise than the wavelet transform. Key-Words: Ultrasonic inspection, Hilbert-Huang Transform, Wavelet Transform, denoising scheme.
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