漏磁检测方法实现管道缺陷图形重构技术的研究

Research on Image Reconstruction Techniques of Metal Loss Defects from Magnetic Leakage Signals

为了实现地下油气输送管道内层腐蚀、裂缝、泄漏状况的检测以及评估 ,探讨了管道缺陷的图形重构技术。缺陷漏磁场可由简单的恒定磁通的等效面偶极子来模拟 ,缺陷重建模型由一系列等效面偶极子阵列分布的截面组成 ,并采用了逆向矩阵求解算法得到方程最优解。理论分析和计算结果表明 ,该模型和算法灵活地实现了管道缺陷的视图化。

Metal loss defects in a buried pipeline are detected by magnetic flux leakage technique. A generalized inverse method and singular value decomposition for reconstructing the magnetic image of arbitrary flaws are presented. These techniques are used on the magnetic flux leakage generated when the structure is magnetized. The leakage field from the flaws is simulated by using a simple constant permeability model. The recovery model is constructed by using a grid of magnetic plane dipoles at the region of the flaws. The analysis and computations demonstrate the feasibility of imaging surface breaking flaws with complex profiles of the pipelines.