Automobile Assembled Meter Recognition Technolgy Based On Machine Vision

Automobile Instrument is an indispensable vehicle component, which is responsible for recording and displaying the various data. According to requirements of more beautiful, more functional, and lighter for the Automobile Instrument, manufacturing and testing of Automobile Instrument is supposed to be substantially improved. Now in automotive instrument testing area manpower methods of judging whether the gauge indicators are pressing or between graduation lines, whether the warning lights are lit, whether there are surface defects are commonly used to determine the quality of products. These methods are influenced by subjective factors, detecting range and fatigue degree, which would lead to big errors and poor reliability. As the rapid development of digital image processing technology, computer vision is beginning to be used in Automobile Instrument detection.Aim of the subject is that based on machine vision technology, image processing methods could be used in automatic identification of Automobile Instrument readings, instead of manually identify which is boring and tired with poor reliability. Firstly, this paper introduces the concepts of machine vision and automobile instrument, development and application in related area. Secondly, overall program of image capture and image processing is described. Thirdly, image processing theory and methods are introduced in detail. Methods of image preprocessing are studied, the image quality is greatly improved by gray level transformation, filtering, binarization etc; region labeling and indicator-region-extraction methods based on size of the area, shape and color feature are propose, and achieved good results; line extraction is achieved by Hough Transform and Least Square Method; the reading is determined in two ways of angle method and number method, and line-cross-method is proposed to identify numbers quickly and effectively; the automobile instrument arrangement is divided into two kinds: linked and independent, different segmentation methods are proposed to divide automobile instrument into single segmentation.In this paper, based on detailed analysis of image processing algorithm, recognition software for automobile instrument reading is developed on MATLAB platform, the speed and accuracy is verified by experiments,the sources of errors are analyzed. The acuracy can satisfy the practical requirements ,however the speed is to be improved, which is of certain practical value.