基于级联神经网络的型钢表面缺陷检测算法

深度学习在缺陷检测方面具有优越性能，然而在工业应用过程中由于缺陷概率低，无缺陷图像的检测过程占据了大部分计算时间，严重限制了整体上的有效检测速度。针对上述问题，提出一种基于级联网络的型钢表面缺陷检测算法SDNet。该算法分为两个阶段：预检阶段和精检阶段。预检阶段采用基于深度可分离卷积（DSC）以及多尺度并行卷积的轻量化ResNet预检网络，判断型钢表面图像是否存在缺陷；精检阶段以YOLOv3作为基准网络对图像中的缺陷进行准确分类与定位，并在主干特征提取网络以及预测分支中引入改进空洞空间金字塔池化（ASPP）模块以及对偶注意力模块，以提升网络的检测性能。实验结果表明，SDNet在1 024像素×1 024像素图像上的检测速度达到每秒120.63帧，准确率达到92.1%。与原YOLOv3算法相比，所提算法的检测速度是原YOLOv3算法的3.7倍，检测精度提高了10.4个百分点，可应用于型钢表面缺陷的快速检测。

Section steel surface defect detection algorithm based on cascade neural network

Deep learning has superior performance in defect detection， however， due to the low defect probability， the detection process of defect-free images occupies most of the calculation time， which seriously limits the overall effective detection speed. In order to solve the above problem， a section steel surface defect detection algorithm based on cascade network named SDNet （Select and Detect Network） was proposed. The proposed algorithm was divided into two stages： the pre-inspection stage and the precise detection stage. In the pre-inspection stage， the lightweight ResNet pre-inspection network based on Depthwise Separable Convolution （DSC） and multi-scale parallel convolution was used to determine whether there were defects in the surface image of the section steel. In the precise detection stage， the YOLOv3 was used as the baseline network to accurately classify and locate the defects in the image. In addition， the improved Atrous Spatial Pyramid Pooling （ASPP） module and dual attention module were introduced in the backbone feature extraction network and prediction branches to improve the network detection performance. Experimental results show that the detection speed and the accuracy of SDNet on 1 024 pixel×1 024 pixel images reach 120.63 frames per second and 92.1% respectively. Compared to the original YOLOv3 algorithm， the proposed algorithm has the detection speed of about 3.7 times and the detection precision improved by 10.4 percentage points. The proposed algorithm can be applied to the rapid detection of section steel surface defects.