Research On The Measurement System Of The Width Of The Middle Board Of Mobile Phone Based On Machine Vision

Currently,the competition of mobile phone market is fierce,and the quality of mobile phone is an important factor for people to choose mobile phone brand,the cell phone is composed of the battery and the back cover of the screen motherboard.The screen and the motherboard are installed on the front side of the middle board,while the battery and the back cover are installed on the back side of the middle board.Therefore,the size of the board in the mobile phone directly affects the quality of mobile phone.In the past,mobile phone manufacturers manually measured the width and size of the inside board of mobile phones by using image measuring instrument,but the measurement method was cumbersome and inefficient.In this paper,the visual measurement technology is introduced into the measurement of the inner width of the mobile phone,and designing a set of visual measurement system of the inner width of the mobile phone.The research content of this paper includes the following points:1.An overall scheme is designed based on the measuring system of the inside width of the mobile phone by machine vision,including: a design of image acquisition platform,an operating principle visual measurement system and a software of vision measurement.2.The principle and performance of hardware equipment such as optical control for lens light source of industrial camera in image acquisition platform are analyzed.The appropriate hardware device is selected to build the image acquisition platform,according to the result of parameter calculation.From the collection results,the initial image data obtained with this measurement system is more accurate.3.The software for measuring the width and dimension of the mobile phone is developed by combining the programming language and the Visionpro visual algorithm library of Cognex,the vision measurement software consists of image processing and measurement modules of the camera calibration module of the image acquisition module,in which the calibration module can complete the nonlinear distortion calibration of thecamera and the calibration image processing module uses the median filter algorithm Pat Max template matching positioning algorithm,Sobel edge detection algorithm.4.Select multiple mobile phone mid-board to verify the measurement error and repeated measurement errors of the visual measurement system,and compare the measured dimensions of the image measuring instrument in accordance with the national standard GB/T 24762-2009 and the same mobile phone mid-board through the visual measurement system The repeated measurement of the inner width dimension verified that the set of visual measurement system met the measurement error requirements of the project.