Design And Implementation Of Home Gas Meter Code Disk Identification System

With the expansion of urban scale and the continuous improvement of urbanization level in China,the popularity rate of urban residents’ natural gas consumption is also getting higher and higher,mechanical membrane gas meter is widely used in the measurement of natural gas of family users.However,the difficult problem of meter reading has not been solved well.At first,the way of meter reading is usually manual meter reading,and there are some shortcomings in the waste of human resources and the low efficiency of the meter reading.Another type of prepaid gas meter,although no manual meter reading is needed,has the disadvantages of low reliability and cumbersome method.Based on the analysis of the domestic and foreign common advantages and disadvantages of the gas meter reading system case,the paper proposed a method based on machine vision of domestic gas meter code automatic identification system.The project designed the mechanical structure of gas meter code automatic identification system device,using the principle of mirror reflection,the camera module could capture the code disk image in the mirror to identify the code,not only reduced the size of the device,but also allowed users to view the gas meter disk when using the device.Considering that the gas meter code disk automatic identification system designed by this project needs to be applied to thousands of households,low power consumption and low cost becomed the necessary considerations.Therefore,this project chose low-cost OV7670 as core sensor of image acquisition module,and low power STM32L476 as core processor.The processing of all image data was completed in the microcontroller,the final identification results were sent to the users’ terminal and the Gas Company through the wireless module.The core technology of the system lay in the innovative image processing algorithm based on the MCU platform.Digital area automatic location algorithm could find the digital area in the gas meter code disk,and then used the automatic segmentation algorithm of digital characters could extract the single number in the digital area.After obtaining a single number,the adaptive threshold segmentation algorithm based on the whole row mean filter was applied to denoise the image.Finally,through the template matching algorithm and the morphological analysis algorithm,the system could identify the number accurately in the gas meter code disk.The system could also compress the collected pictures in JPEG format,and reduced the amount of image data greatly,which could be sent to users and Gas Company directly through wireless modules.After one year’s development and debugging,the automatic identification system of the domestic gas meter has achieved the basic functions.The good mechanical mechanism and light source design can effectively avoid the influence of ambient light on image acquisition.The system can receive the reading instructions sent by the user at any time.In 5 seconds,the system can be started,the image can be collected and processed,and the recognition result can be sent.The recognition accuracy is up to 99.96%,with good user experience and high meter reading efficiency and accuracy.