A Laser Scanning System for the Inspection of Fasteners in Railways

With the rapid growth of high-speed railways, the demand for automatic railway inspection, including fastener inspection, has increased. Most studies related to fastener inspection have focused on image processing and recognition technologies, which entail high computational costs and make real-time implementation difficult in high-speed applications. This paper proposes a laser scanning system based on motion images to improve time efficiency in fastener inspection. Compared with conventional methods, the captured image using the proposed method is of high contrast, easy to process and provides much depth information, which is useful for detection. We also introduced mathematical descriptions of the proposed method. Finally, we built an experimental system to simulate the practical system in high-speed railways at a speed of 300 km/h. Image processing achieved a recognition accuracy of 98.25%, implying the proposed method can inspect a high-speed moving object with high accuracy.