A real-time visual and control system for screw holes location and shielding of automobile wheel hubs.

In this paper, machine vision technique is used to solve screw holes shielding problems during spray painting in wheel hub making industry. The shape and geometric structure of automobile wheel hub are studied; the wheel hub image is captured from the assembly line; image processing method is used to recognise the holes on the wheel hub surface; the diameters, positions and some other parameters are calculated; a 2D motion control method is used to locate the central position of screw holes; a compact shielding device is developed to cover the holes by special balls. This method can be used for all types of wheel hubs, and the labour costs can be reduced. The productive process is more efficient and automatic.