The Process Control in Manufacturing: Inspection of Ball Bearings

A real industrial case has been analyzed and is discussed in this paper. Significant percentage of defective ball bearings is not detected during the final inspection in the only manual station of the automatic assembly line. The main specifications of an inspection system, which is based on artificial vision, are pointed out. The system configuration (camera, lighting and ball bearing support) is described in detail. The visibility of all surfaces has been optimized using one central conic and four lateral mirrors. In off-line tests, the described algorithms allowed the recognition of most surface defects. Interactive and user-friendly calibration procedures have also been defined.