QIU Zu-rong, LU Yao-huan, XUE Jie, PANG Jiang-miao, LI Hao-peng
（State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China）
Abstract： Under the premise of fully respecting current national standard of table tennis ball, this paper presents an integrated and effective method for testing diameter, roundness and hardness of table tennis ball based on vision measurement. Firstly, camera calibration is performed by 40 mm gauge block to capture the images of table tennis ball in static and pressed state in an appropriate lighting condition. Then image binarization and extraction of image contour are carried out. The least square method is used to fit its center. Finally, the diameter, roundness and hardness are calculated. The measurement data are analyzed by using the method presented in this paper for table tennis ball with known parameter data and with unknown parameter data. Experimental results show that this method can improve measurement accuracy and provide a technical basis for the online testing and integration measurement of table tennis ball.
Key words： table tennis ball； diameter； roundness； hardness； vision measurement
CLD number： TP391.4 Document code： A
Article ID： 1674-8042（2019）01-0001-08 doi： 10.3969/j.issn.1674-8042.2019.01.001
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乒乓球直径、 圆度、 硬度的视觉检测方法
裘祖荣， 路遥环， 薛 洁， 庞江淼， 李浩鹏
（天津大学 精密测试技术与仪器国家重点实验室， 天津300072）
摘 要: 在充分尊重乒乓球现行国家标准的前提下， 提出了一种基于视觉检测的乒乓球直径、 圆度及硬度一体化检测方法。 首先， 通过调整光照环境， 使用40 mm量块对相机进行标定后， 对静止和施压状态下的乒乓球进行拍摄； 然后对图像进行二值化处理和轮廓提取， 并用最小二乘法拟合圆心， 计算直径、 圆度和硬度。 对已知参数数据和未知参数数据的乒乓球用提出的方法进行了测量并分析测量数据， 结果表明， 该方法能够提高乒乓球参数测量结果的准确性， 为乒乓球的在线检测和参数一体化测量提供技术基础。
关键词: 乒乓球； 直径； 圆度； 硬度； 视觉检测
引用格式： QIU Zu-rong, LU Yao-huan, XUE Jie, et al. Vision testing method for diameter, roundness and hardness of table tennis ball. Journal of Measurement Science and Instrumentation, 2019, 10(1)： 1-8. ［doi： 10.3969／j.issn.1674-8042.2019.01.001］
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