列车闸瓦钎及闸瓦故障图像检测算法研究

Research on image detection algorithm of freight train brake shoe bolt and brake shoe fault

列车闸瓦钎及闸瓦状态正常与否对于货运列车安全运行极其重要,为此提出了一种改进的SSD目标检测算法,对货运列车闸瓦钎及闸瓦的缺失进行检测。首先将深度可分离卷积模块引入ResNet50网络模型,使其参数数量减少约50%,以提高检测效率。其次,将改进后的ResNet50网络模型替换SSD中的VGG16网络,以改善SSD网络模型的特征提取能力。然后利用高、低层特征融合的方法,将网络中Conv5_3和Conv7_2分别与Conv4_6和Conv6_2进行特征融合,提高检测精度。最后通过自建的货运列车制动部件缺失数据集对网络进行训练获取比较准确的网络权重。实验结果表明,改进后的SSD算法在闸瓦钎丢失检测中准确率达到96.85%,召回率达到89.50%;在闸瓦丢失检测中准确率达到97.01%,召回率达到97.01%,可以满足列车闸瓦钎及闸瓦缺失检测需求。

The state of brake shoe bolt and brake shoe is of great importance to the safe operation of freight trains. Therefore,an improved SSD(single shot multi-box detector) target detection algorithm was proposed to detect the missing brake shoe bolt and brake shoe of freight trains. Firstly, the depthwise separable convolution module was introduced into the ResNet50 network model to reduce the number of parameters by about 50%, thereby improving the detection efficiency.Secondly, the improved Res Net50 network model was employed to replace the VGG16 network in SSD to improve the feature extraction capability of the SSD network model. Then, Conv5_3 and Conv7_2 were combined with Conv4_6 and Conv6_2 respectively by the method of high level feature and low level feature fusion to improve the detection accuracy.Finally, the network was trained to obtain more accurate weights through the self-built dataset of freight train brake component loss. The experimental results show that the improved SSD algorithm could attain an accuracy of 96.85% and a recall of 89.50% in brake shoe brazing loss detection, and an accuracy of 97.01% and a recall of 97.01% in the detection of brake shoe loss, thus meeting the requirement of missing brake shoe bolt and brake shoe detection.