Research Of Software And Experiment Of High Precision Measurement And Automatic Assembly System Of Precise Parts Based On Machine Vision

The machinery and electronic products are becoming precise, portable and mobile to use for the human life as well as changing their lifestyle. The precise microminiature mechanical and electrical products have the features as low energy consumption, stable and reliable performances, and are widely used in kinds of fields. The product are made by different crafts, materials and connection technology so that they always can not be manufactured by once, but are made by precision parts which size is lie between sub-millimeter and several millimeter. So high precision measurement of the size of parts and accurate positioning for components is the key to affect the product manufacturing and production efficiency. At present, the work of the precision measurement and precision assembly for microminiature parts is performed manually by skilled workers under microscope with low production efficiency. The manual assembly needs good professional skills, so it is payed widely attention to find related technologies and research of high precision measurement and automatic assembly to solve the problem.Based on machine with the characteristic of flexible assembly, the system of high-precision measurement and automatic assembly of precise parts had become an effective way to solve the problem.In this research paper, the theory of optical measurement, image processing technology and visual positioning technology were used to build the assembly system. The image preprocessing algorithm was analyzed and compared. In addition, the mixture distortion model of the radial distortion and centrifugal distortion was also presented. And Zhang’s camera calibration method was used to calibrate the camera that reduced the influence of camera lens distortion on the measurement accuracy. Canny algorithm and elliptic curve fitting method was adopted to extract the sub-pixel accuracy edge, so that the measurement and location accuracy was improved providing the basis for automatic assembly of the parts. According to requirement of this project, searching and combination algorithm was designed using the thickness information of the parts to improve the success rate and percentage of pass of assembling. The user interface and a database management system was designed based on VB.NET platform. It was used to store the size of parts and location information in the process of assembling. And then TCP/IP Ethernet communication system and serial port communication system were designed. It is convenient to exchange data and the information between subsystems of slave machine and principal machine. Finally, this paper was completed the research of system of high-precision measurement and automatic assembling of the precise parts based on machine vision, and setted up the experimental prototype. The experimental results were shown that the measurement accuracy of the measuring system designed was reached in this paper as 0.0066 mm, and the concentricity accuracy of assembling was reached 0.017 mm which satisfied the requirement of industry.