Department of Physics, Zhengzhou University of Light Industry, Zhengzhou, 450002, China.
Sensors (Basel). 2012;12(1):334-46. doi: 10.3390/s120100334. Epub 2011 Dec 30.
Train wheel sets must be periodically inspected for possible or actual premature failures and it is very significant to record the wear history for the full life of utilization of wheel sets. This means that an online measuring system could be of great benefit to overall process control. An online non-contact method for measuring a wheel set's geometric parameters based on the opto-electronic measuring technique is presented in this paper. A charge coupled device (CCD) camera with a selected optical lens and a frame grabber was used to capture the image of the light profile of the wheel set illuminated by a linear laser. The analogue signals of the image were transformed into corresponding digital grey level values. The 'mapping function method' is used to transform an image pixel coordinate to a space coordinate. The images of wheel sets were captured when the train passed through the measuring system. The rim inside thickness and flange thickness were measured and analyzed. The spatial resolution of the whole image capturing system is about 0.33 mm. Theoretic and experimental results show that the online measurement system based on computer vision can meet wheel set measurement requirements.
轮对必须定期检查，以发现可能或实际的早期故障，记录轮对的整个使用寿命的磨损历史非常重要。这意味着在线测量系统对于整体过程控制将非常有益。本文提出了一种基于光电测量技术的轮对几何参数在线非接触测量方法。使用具有选定光学透镜和帧抓取器的电荷耦合器件 (CCD) 相机来捕获由线性激光照明的轮对的光轮廓图像。图像的模拟信号被转换为相应的数字灰度值。“映射函数方法”用于将图像像素坐标转换为空间坐标。当列车通过测量系统时，拍摄轮对的图像。测量并分析了轮辋内厚度和法兰厚度。整个图像采集系统的空间分辨率约为 0.33 毫米。理论和实验结果表明，基于计算机视觉的在线测量系统可以满足轮对测量的要求。
