世界桥梁
世界橋樑
세계교량
World Bridges
2015年
6期
47-50,57
,共5页
小波去噪%GCV准则%小波阈值%小波变换%斜拉桥%健康监测%挠度
小波去譟%GCV準則%小波閾值%小波變換%斜拉橋%健康鑑測%撓度
소파거조%GCV준칙%소파역치%소파변환%사랍교%건강감측%뇨도
wavelet de-noising%GCV principle%wavelet threshold value%wavelet transfor-mation%cable-stayed bridge%health monitoring%deflection
为了准确确定小波阈值，改善阈值函数的降噪效果，提出一种基于GCV准则确定阈值和改进的阈值函数相结合的小波去噪方法。首先对信号进行小波变换，定义基于小波系数的GCV函数，通过对其进行优化求解最小值来选取小波阈值，然后采用改进的阈值函数对小波系数进行处理，最后对处理后的小波系数进行重构，得到去噪后的信号。通过一已知信号和噪声的数值算例，对比了该方法与常用的确定阈值方法和软阈值函数的去噪效果，验证了该方法具有更好的去噪效果。应用该方法，对一座斜拉桥的健康监测系统采集的实测挠度数据进行分析处理，结果表明，该方法有效降低了噪声影响，降噪后的挠度与数值结果接近。
為瞭準確確定小波閾值，改善閾值函數的降譟效果，提齣一種基于GCV準則確定閾值和改進的閾值函數相結閤的小波去譟方法。首先對信號進行小波變換，定義基于小波繫數的GCV函數，通過對其進行優化求解最小值來選取小波閾值，然後採用改進的閾值函數對小波繫數進行處理，最後對處理後的小波繫數進行重構，得到去譟後的信號。通過一已知信號和譟聲的數值算例，對比瞭該方法與常用的確定閾值方法和軟閾值函數的去譟效果，驗證瞭該方法具有更好的去譟效果。應用該方法，對一座斜拉橋的健康鑑測繫統採集的實測撓度數據進行分析處理，結果錶明，該方法有效降低瞭譟聲影響，降譟後的撓度與數值結果接近。
위료준학학정소파역치，개선역치함수적강조효과，제출일충기우GCV준칙학정역치화개진적역치함수상결합적소파거조방법。수선대신호진행소파변환，정의기우소파계수적GCV함수，통과대기진행우화구해최소치래선취소파역치，연후채용개진적역치함수대소파계수진행처리，최후대처리후적소파계수진행중구，득도거조후적신호。통과일이지신호화조성적수치산례，대비료해방법여상용적학정역치방법화연역치함수적거조효과，험증료해방법구유경호적거조효과。응용해방법，대일좌사랍교적건강감측계통채집적실측뇨도수거진행분석처리，결과표명，해방법유효강저료조성영향，강조후적뇨도여수치결과접근。
To correctly determine the wavelet threshold value and improve the noise allevia‐ting effect of the threshold function ,a wavelet de‐noising method based on the combination of GCV principle and improved threshold function to determine threshold value was put forward . First ,the signals must be transformed into wavelet to define the GCV function based on wavelet coefficient .Then the function was optimized ,so that the minimum value to select the wavelet threshold value could be selected .Subsequently ,the improved threshold function was used to process the wavelet coefficient ,and the wavelet coefficient processed was rebuild to gain the sig‐nal after de‐noising .Based on the numerical calculation example of a known signal and noise ,the method was compared with conventional threshold determining method and the soft threshold function in terms of the de‐noising effect ,verifying that the mothod has better de‐noising effect . The method was used to analyze and handle the measured deflection data gained by the health mo‐nitoring system of a cable‐stayed bridge .The results of the analysis indicate that the method ef‐fectively reduces the effect of noise ,the deflection after de‐noising is approximate to the calculat‐ed value .
