CAJ | 학술논문

针对超声波时差衍射法（TOFD）D 扫描图像，提出一种新的侧向波抑制算法。该方法首先将图像分解为一维信号，对一维信号进行小波去噪后重构以去除图像噪声。通过讨论参数对滤波结果的影响来比较 RLS 自适应滤波算法和变步长 LMS 自适应滤波算法，从而选择对参数不敏感的变步长 LMS 算法。最后在变步长 LMS 算法的基础上提出一种改进的自适应滤波方法，以去除侧向波与缺陷波未混叠的缺陷图像的残余部分。试验结果表明提出的算法是有效的。
침대초성파시차연사법（TOFD）D 소묘도상，제출일충신적측향파억제산법。해방법수선장도상분해위일유신호，대일유신호진행소파거조후중구이거제도상조성。통과토론삼수대려파결과적영향래비교 RLS 자괄응려파산법화변보장 LMS 자괄응려파산법，종이선택대삼수불민감적변보장 LMS 산법。최후재변보장 LMS 산법적기출상제출일충개진적자괄응려파방법，이거제측향파여결함파미혼첩적결함도상적잔여부분。시험결과표명제출적산법시유효적。
In order to be able to suppress direct wave of TOFD (time of flight diffraction)D scanning image,a new method was introduced.In order to remove noise,firstly the TOFD D scanning image was decomposed into a series of one-dimensional signals.Then wavelet denoising was used to remove noise of one-dimensional signal.Finally,with a series of processed signals a new image was reconstructed.The effect of parameters on the filtering results would be discussed for the comparison of RLS (recursive least square)adaptive filtering algorithm and variable step-size LMS (least mean square)adaptive filtering algorithm,and variable step-size LMS adaptive filtering algorithm would be used.Moreover,an improved algorithm was introduced to suppress direct wave of a non-near surface defect image.The result demonstrated that the algorithm was a-vailable.