earticle

영어

In ultrasonic nondestructive testing, the presence of noise makes great trouble for defect recognition, so it is very necessary to reduce noise in collected ultrasonic signal. In this paper a de-noising algorithm of ultrasonic echo signal based on wavelet transform and Independent Component Analysis (ICA) was presented. First, wavelet transform was used to decompose original noisy signal, and then ICA was applied to decomposed detail coefficients, separated independent components were evaluated by threshold, noise was filtered, and finally, de-noised ultrasonic signal was obtained by wavelet reconstruction. Simulation and experimental results showed that the proposed algorithm can improve signal-to-noise ratio, meanwhile, overcome some other de-noising algorithms’ shortcoming of losing useful information in de-noising, the performance is superior to wavelet threshold de-noising algorithm.