基于梅花针计数的冷水水表检定方法

Verification Method of Cold Water Meter Based on Count of Plum Blossom Needle

针对企业水表检定效率低、精度差以及人工成本大等问题,在分析水表检定原理、总结传统水表指针示数判读方法的基础上,运用机器视觉技术设计了更高精度、更高效率的水表检定方案,开发了一套基于水表梅花针计数的冷水水表检定系统。该系统通过模板匹配技术自动定位梅花针位置以确定相机ROI区域,然后采集梅花针转动图像序列,将其转换为二值图像后,自动裁切出标记点图像并计算其平均灰度值,也就将采集到梅花针转动序列图像转换为可统计分析的行向量,统计该向量的峰值个数即得到梅花针在检定过程中的转动齿数,进而计算出流过该水表的水体积、计量误差,并与《JJG162-2009冷水水表检定规程》中通水流量标准值比对,进而判定该水表是否合格。该系统已应用于成都汇锦水务发展有限公司水表检定装置上,能大幅提升生产效率、降低人工成本。该研究对于企业自动化升级改造、智慧工厂建设有重要意义。

Aiming at the problems of low efficiency,poor precision and high labor cost of water meter verification in enterprises,on the basis of analyzing the principle of water meter verification and summarizing the traditional method of water meter indicator reading,this paper designs a higher precision and higher efficiency water meter verification scheme by using machine vision technology,and develops a set of cold water meter verification system based on the plum blossom needle counting of water meter.The system uses template matching technology to automatically locate the position of the plum blossom needle to determine the ROI area of the camera;then,collect the rotation image sequence of the plum blossom needle,and convert it into a binary image,automatically cut out the mark point image and calculate its average gray value,convert the rotation sequence image of the plum blossom needle to a row vector that can be statistically analyzed;and then count the number of peaks of the vector,that is to say,the number of rotating teeth of the plum blossom needle in the verification process is obtained,and then the volume of water flowing through the water meter and the measurement error are calculated,and compared with the standard value of water flow in the verification regulation of"JJG162-2009 Cold Water Meter Verification Regulations",so as to determine whether the water meter is qualified.The system has been applied to the water meter verification device of Chengdu Huijin Water Development Co.,Ltd.to greatly improve the production efficiency and reduce the labor cost.This research is of great significance to the upgrading of enterprises automation and the construction of smart factories.