平面电磁层析成像钢轨探伤

Plane Electromagnetic Tomography Rail Track Inspection

为了增强电磁钢轨探伤中纵向裂纹的检测效果,满足钢轨探伤的定位、分类及可视化需求,提出平面电磁层析成像钢轨探伤方法。根据75kg/m重载钢轨的实际尺寸及线圈的电磁特性,设计应用于钢轨探伤的传感器阵列。探讨采用不同灵敏度矩阵计算方法(场量提取法、扰动法)所得灵敏度矩阵的质量。采用人群搜索算法优化灵敏度矩阵,降低灵敏度矩阵条件数,改善灵敏度矩阵的病态性,提高重建图像质量。仿真及实验结果表明,该文方法可有效重建钢轨损伤的位置与形状,对纵向裂纹检测效果良好,证明平面电磁层析成像方法在钢轨探伤中的可行性。

In order to increase the detection ability of longitudinal crack of electromagnetic rail inspection and meet the demand of defect localization,classification and visualization in rail inspection,a rail inspection method based on plane electromagnetic tomography was proposed.According to the structure of 75 kg/m heavy load railway and the character of coil,a sensor array was designed for rail inspection.The quality of sensitivity matrix that calculated by using different methods(field extraction method and perturbation method)was discussed.The seeker optimization algorithm was used for the sensitivity matrix to decrease the condition number of sensitivity matrix and improve the quality of reconstructed image.Thus,the quality of reconstruction image was increased.Simulation and experiment results show that,the location and shape of defects can be reconstructed effectively and detection ability of longitudinal crack is well by using the proposed method.The feasibility of plane EMT method in rail inspection was proved.