Automatic Visual Inspection for Catenary on High-Speed Railways

摘要

Defects on catenary components are a major part of device faults as a result of a much higher tension on high-speed catenary, such as looseness of bolts, component broken, and component missing. Traditional inspection on catenary components has to be performed only at night with human eyes. Not only the inspection speed is very slow, but also the inspection results are not reliable, as a result of the poor lighting environment and long-time working tiredness. In this paper, we present an automatic visual inspection system for checking the status of components on catenary. A dedicated designed camera system is mounted on an inspection car, which is composed of many super-high-resolution area-scan cameras with different directions and fields of view. The camera system covers almost all the components to be checked and gives great details of each component. A post detection module is integrated in order to trigger the cameras and lighting device at a proper location, which utilizes several laser distance sensors pointing at the steady arms. Considering the great data storm at each catenary post, high-performance servers with GPU acceleration are used, and technologies of multi-thread and parallel computing are exploited. Furthermore, an intelligent analysis framework is proposed, which uses structural analysis to localize each component in the image, and perform automatic detection based on different features such as geometry, texture, and logic rules. The system can operate at a maximum speed of 160 km/h in both directions, and has been successfully used in China highspeed railways, which shows great advantages in the catenary inspection application.