Automatic Crack Detection and Classification Method for Subway Tunnel Safety Monitoring

Sensors

Wenyu Zhang¹  Zhenjiang Zhang²  Dapeng Qi¹ 

[1] School of Electronic and Information Engineering, Key Laboratory of Communication and Information Systems, Beijing Municipal Commission of Education, Beijing Jiaotong University, Beijing 100044, China;

关键词: crack detection;    crack classification;    subway tunnel;    line scan cameras;   

DOI  :  10.3390/s141019307

来源: mdpi

【 摘 要 】

Cracks are an important indicator reflecting the safety status of infrastructures. This paper presents an automatic crack detection and classification methodology for subway tunnel safety monitoring. With the application of high-speed complementary metal-oxide-semiconductor (CMOS) industrial cameras, the tunnel surface can be captured and stored in digital images. In a next step, the local dark regions with potential crack defects are segmented from the original gray-scale images by utilizing morphological image processing techniques and thresholding operations. In the feature extraction process, we present a distance histogram based shape descriptor that effectively describes the spatial shape difference between cracks and other irrelevant objects. Along with other features, the classification results successfully remove over 90% misidentified objects. Also, compared with the original gray-scale images, over 90% of the crack length is preserved in the last output binary images. The proposed approach was tested on the safety monitoring for Beijing Subway Line 1. The experimental results revealed the rules of parameter settings and also proved that the proposed approach is effective and efficient for automatic crack detection and classification.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.