基于脉冲涡流热成像的铁磁性构件缺陷检测

Defect detection of ferromagnetic components based on pulsed eddy current thermal imaging

针对铁磁性构件损伤探测问题,提出了二维大津法(Ostu)与多尺度形态学梯度边缘检测相结合的方法,该方法基于脉冲涡流热成像的缺陷无损检测技术,处理分析红外图像,得到缺陷边缘特征,用于监测铁磁性构件的健康状态。首先利用脉冲涡流热成像装置对铁磁性构件加热,并使用红外热像仪摄取红外图像;然后利用二维Ostu算法对获得的红外图像进行分割,得到二值缺陷区域,并对其进行连通性计算,从而得到涡流线圈内缺陷区域,提取裂纹缺陷;最后对所得裂纹缺陷进行多尺度形态学梯度边缘检测,并运用物象关系,测量缺陷几何尺寸。构件缺陷试验证明该方法对缺陷边缘检测效果良好,实现了铁磁性构件缺陷的无损检测。

Aiming at the damage detection of ferromagnetic components,a method combining two-dimensional Ostu and multi-scale morphological gradient edge detection is proposed.Based on the defect non-destructive detection technology of pulsed eddy current thermal imaging,the infrared image is processed and analyzed to obtain the defect edge features to monitor the health of ferromagnetic components.Firstly,the ferromagnetic member is heated by the pulse eddy current thermal imaging device,and the infrared image is taken by the infrared camera.Then the obtained infrared image is segmented by the two-dimensional Ostu algorithm to obtain the binary defect region,and the connectivity calculation is performed.Therefore,the defect area in the coil is obtained,and the crack defect is extracted.Finally,the multi-scale morphological gradient edge detection is performed on the obtained crack defect,and the geometrical dimension of the defect is measured by using the image relationship.The component defect test proves that the method has good effect on the defect edge detection and realizes the quantitative detection of defects.