列车轮对内侧距光学快速测量系统设计及实现  

Design and Implementation of Optical Fast Measuring System for Distance between Backs of Train Wheel Flanges

作　　者：肖立明[1] 方宇[1] 胡定玉[1] 黄建坊 XIAO Liming;FANG Yu;HU Dingyu;HUANG Jianfang(School of Urban Tail Transportation,Shanghai University of Engineering Science,Shanghai 201620,China;Xiamen Rail Transit Group Co.,Ltd.,Xiamen 361021,China)

机构地区：[1]上海工程技术大学城市轨道交通学院,上海201620 [2]厦门轨道交通集团有限公司,福建厦门361021

出　　处：《自动化仪表》2020年第3期93-96,101,共5页Process Automation Instrumentation

摘　　要：列车轮对内侧距的准确、及时测量,是列车检修中必不可少的工作。目前,主要使用专用机械卡尺测量轮对内侧距。由于机械卡尺读数与记录都是人工操作,步骤繁琐。针对以上问题,设计了基于三角测距原理的列车轮对内侧距快速测量系统。首先,采用嵌入式处理器驱动摄像机的方式采集轮对内侧激光点图像,并根据激光光斑在像素平面的移动特征,提出快速搜索光斑初步位置方法,剪裁出含有光斑的局部图片;然后,利用阈值分割法和图像形态学处理法,过滤局部图片中光斑的背景噪声;最后,根据灰度重心法精确提取光斑中心坐标,计算轮对内侧距。为验证该系统的可行性,与轮对内侧距机械测量卡尺进行对比试验。试验结果表明,轮对内侧距光学测量方法准确有效。该系统能够大大缩短轮对内侧距测量时间,提高工作效率,在列车日常维护中具有一定的应用价值。Precise and timely measurement of distance between backs of wheel flanges plays a key role in railway maintenance.At present,distance between backs of wheel flanges is measured mainly by a special mechanical caliper,but it is complex to handle due to the manual operation of its reading and record.In order to deal with this problem,a rapid optic measurement system of distance between backs of wheel flanges is designed based on laser triangulation principle.Firstly,capture the laser spot image on the inner wheel by using MCU combined with a camera,and then propose the method of a fast search on the preliminary position of the spot to clip a partial image of the spot according to the moving feature of laser spot on the pixel plane.Secondly,use the threshold segmentation method and the image morphology method to filter the background noise of the local spot.Finally,calculate the distance between backs of wheel flanges after center coordinates of the spot can be extracted precisely based on the gray centroid method.In order to test the feasibility of the rapid optic measurement system of the distance between backs of wheel flanges,the comparative experiment was conducted between the rapid optic measurement method and the mechanical caliper measurement method,obtainting the result that our method is more pricise and effective.Therefore,the system presented in this paper has advantages of time reduction in distance between backs of wheel flanges measurement and efficiency improvement,which has practical values in train’s daily maintenance.

关 键 词：轮对内侧距 激光三角测距 激光光斑快速定位 图像处理 光斑中心提取 阈值分割 非接触测量 灰度重心法 

分 类 号：TH-741.1[机械工程]