Automatic Detection Of Smart Meter Display Defects Based On Machine Vision

The status of smart meter in the National Smart Grid will become more and more important.As the terminal sensing unit of electric power metering,intelligent meter needs to display the related information on the LCD display clearly and conveniently.In the production process of smart meters,we need to verify the execution of key commands such as parameter settings,control instructions,and check the quality of LCD panels and the appearance of nameplates,so as to determine whether the meter is in line with national standards and related quality requirements.The display is one of the most important components of smart meters.It can reflect the user’s power information,electric power information and time information on the screen.So the quality assurance of the display has an important influence on the production of smart meters.If the above criteria in manual testing environment,especially for the smart meter display characters,brightness and position detection,we can’t guarantee the quality of smart meters to meet the requirements,so the production line need an automatic detection system of intelligent meter display.This paper designs and implements a detection system for the defects of the intelligent meter display screen based on image processing.The system can detect the characters,luminance and installation location defects in the intelligent meter display by image processing technology.The system is mainly divided into two parts,first using the median filtering,image edge detection,Sobel operator,Roberts operator,Prewitt operator,Hough line detection and image processing algorithm,two value expansion and corrosion on the screen or region extraction method;image pre-processing steps and different use of natural later,through the correction factor regulating corrosion and expansion,and the special structure of the smart meter display screen frame,respectively for the smart meter display characters,brightness and location detection design,realization of display screen inspection qualified requirements.The algorithm program is written in MATLAB language,and the system operation window is written in the C#language.The experimental results show that the system can achieve good results.