Calibration method of water meter based on machine vision
                                                   ZHENG Wenxue1, YUE Zhimin2, TANG Xusheng1, CHEN Dan1
(1.College of Mechanical Engineering and Automation，Fuzhou University, Fuzhou 350108, China;2.Zhengzhou KaiYuan Instrument Company Limited, Zhengzhou 450000, China)

Abstract: Aiming at the problems of low calibration efficiency and insufficient information management function of existing water meter calibration devices, the identification of water meter pointer, eliminating the influence of bubbles, and the automatic transformation of calibration platform were studied. A kind of online water meter detection system based on machine vision was proposed, distance method was used to read water meter pointer reading and passed through template matching, the water meter image were rotated and corrected, polar coordinate transformation was used to expand the subdial into a rectangle, and twodimensional code recognition module were integrated, the verification and data preservation of the water meter was realized. A walking mechanism was designed to drive the camera to take pictures, and a single camera was used to collect images of water meters at five stations.The results indicate that compared with manual reading and manual recording, this method can ensure the accuracy of water meter, improve the efficiency of verification, and make the calibration data traceable.

Key words: distance method; water meter; machine vision