A machine vision system for inspecting bearings

We describe a machine vision system for inspecting bearings, which are an important part of electro-mechanical kWh meters. The system consists of a personal computer with a frame grabber, a black and white progressive scan CCD camera, and a mechanical device with a stepper motor controlled by a special controller connected to the RS232 port of the personal computer. The quality of a bearing depends on the eccentricity of the needle and the length of the needle that extends out of the cylinder. These two parameters are robustly and accurately defined by the Hough transform and the regression methods. The results presented show that the proposed machine vision system allows accurate, reproducible, and robust inspection of bearings of electro-mechanical kWh meters, and it may be a valuable tool for ensuring high-end-product quality.