基于平稳小波变换的管道防腐层微小破损点定位

Small Damaged Point Localization of Pipeline Anticorrosion Layer Based on Stationary Wavelet Transform

中文关键词:  平稳小波变换  埋地管道  防腐层  破损点  定位

英文关键词:stationary wavelet transform  buried pipeline  anticorrosion layer  damaged point  locating

中文摘要:

      为了解决密间隔电位检测技术对管道防腐层微小破损点检测效果不佳的问题，应用有限元方法建立管道杂散电流模型，提取管道防腐层发生微小破损的断电电位信号。提出基于平稳小波变换(Stationary Wavelet Transform，SWT)的断电电位信号分析方法，将信号通过平稳小波分解得到细节系数，细节系数中包含的防腐层微小破损点信息清晰可见。利用软阈值规则对细节系数进行去噪，加强了对破损点信息的识别效果。结果表明：SWT细节系数能够有效表征管道防腐层微小破损点信息从而进行精准定位，且防腐层破损点轴向、周向位置变化，破损面积大小及采样点与破损点位置间距变化都会影响细节系数峰值。该方法检测精度高，可为管道防腐层微小破损点定位提供有效分析手段。

英文摘要:

      To solve the problem that close-interval potential detection technology is not effective in detecting small damaged points of pipeline anticorrosion coatings,the stray current model of the pipeline is established by using the finite element method to extract the switch-off potential signals when the pipeline anticorrosion layer is slightly damaged.By applying the stationary wavelet transform (SWT) to the analysis of the potential switching signal,the signals detail coefficient is obtained by the stationary wavelet decomposition,and the information of small damaged points of pipeline anticorrosion coatings in the detail coefficient can be clearly seen.The soft threshold rule is used to de-noise the detail coefficient,thereby enhancing the recognition effect of damaged point information.The results demonstrate that the detail coefficient of SWT can effectively represent the weak damaged point information.Therefore,it can be employed for the localization of the damaged points.Moreover,the axial and circumferential positions of the damaged points in the anticorrosion layers,the size of the damaged area,the distance between sampling points and the damaged points will affect the peak value of detail coefficients.This method has high detection accuracy and can provide an effective analysis method for locating the small damaged points of pipeline anticorrosion coatings.