Visual detection method of chamfer R on the root bottom of textile workpiece roller

HU Ling-hao1, LIU Chang-jie1, SHI Chun-min2, FU Lu-hua1, LU Gang1

（1. State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China；2. China Railway Test & Certification Center Locomotive & Car Inspection Lab, China Academy of Railway Sciences, Beijing 100015, China）

Abstract： Roller is an important workpiece of automatic spinning machine. Only if the chamfer R on the root bottom of roller’s guide pillar meets processing accuracy requirement can the end face of one roller’s guide pillar match the correct position of another roller’s end face on the guide hole. Therefore, the size of chamfer R on the root bottom of the roller’s guide pillar has an important influence on the operating state of automatic spinning machine. In order to achieve the rapid, automatic and precise measurement of chamfer R on the root bottom of roller, an auto-detection system for roller’s chamfer based on computer vision technology is proposed. Firstly, the principle of measurement based on computer vision technology is introduced. And then the extraction method of chamfer’s characteristic parameters is presented, which uses image processing technique to obtain these characteristic parameters by means of collected images of roller contour, including extraction of region of interest, extraction of subpixel-precise edge, segmentation of arc and line, fitting of geometric primitives, etc. Finally, after experimental verification, the measurement error is within ± 5 μm and repeated accuracy is 0.1 μm. The results show that this measurement method is applicable to not only the chamfer on the textile workpiece, but also the workpieces of shaft type with various of sizes.

Key words：  textile workpiece, roller, chamfer, image measurement, auto-detection

CLD number： TP391.4Document code： A

Article ID： 1674-8042（2018）03-0205-09doi： 10.3969/j.issn.1674-8042.2018.03.001

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罗拉纺织工件根底部倒角R的视觉检测技术研究

胡凌皓1， 刘常杰1， 石春珉2， 付鲁华1， 卢钢1

（1. 天津大学 精密测试技术与仪器国家重点实验室， 天津 300072； 2. 中国铁道科学研究院  中铁检验认证中心机车车辆检验站，  北京 100015）

摘要:罗拉是自动纺织机上的重要工件， 只有罗拉导柱根底部倒角R符合加工精度要求， 才能确保一个罗拉工件的导柱端面能与另一个罗拉工件的导孔的端面以正确位置对合， 因此， 罗拉导柱根底部倒角R的尺寸将直接影响自动纺织机的运行状态。 为实现罗拉根底部倒角的快速、自动、精密测量， 文章提出了一种基于计算机视觉技术的罗拉导柱根底部倒角自动检测系统。 首先， 介绍了测量原理， 即基于视觉测量技术的检测方法； 其次， 详细阐述倒角的特征参数提取技术， 即基于采集得到的罗拉轮廓影像， 进行图像处理以获得根底部倒角特征参数， 包括感兴趣区域的提取、 亚像素边缘的获得、 圆弧和直线段的分割以及倒角的基圆拟合等； 最后， 经实验验证， 该检测方法测量误差在±5 μm内， 重复精度为0.1 μm。 该方法不仅适用于罗拉纺织工件的倒角检测， 也适用于各种尺寸的轴状类型工件的倒角检测。

关键词:纺织工件； 罗拉； 倒角； 影像测量； 自动检测

引用格式：HU Ling-hao, LIU Chang-jie, SHI Chun-min, et al. Visual detection method of chamfer R on the root bottom of textile workpiece roller. Journal of Measurement Science and Instrumentation, 2018, 9(3)： 205-213. ［doi：10.3969／j.issn.1674-8042.2018.03.001］

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