A New High-Speed Algorithm for Center and Rotate Angle of Electronic Components

A machine vision system for SMT-mounting machine usually involves a two-stage algorithm. It first measures the center and rotate angle of the SMD, and then checks each electronic component. The electronic component positioning is an important research content of machine vision in completely automatic SMM. In this paper a new high-speed algorithm of the center and rotate angle is proposed to locate the electronic component. During the locating procedures, it first demarcates the least image area of an electronic component using four limiting checking lines. Then the center and rotate angle of the SMD is calculated using the least area. After that, the precision, speed and characteristic of the new algorithm are researched in this paper. Some other methods such as correct the error, demarcate the least image area of electronic component are also studied. The vision processing software is written in Visual C++ 6.0 and runs on Windows 2000. Experimental results on images is promising, the approximate precision is 1 pixel. The new algorithm combines the principal axis of inertia algorithm and Gray-scale information. It is verified by experiment that this algorithm has a high accuracy, fast execution speed, and can meet the crucial time requirement of a high speed SMT machine