Illumination design of a control system for visual inspection of ceramic tiles

Ceramic tile manufacturing process is almost completely automated. An exception is the final phase, i.e. quality controls, carried out by human. Production lines move relatively fast, increasing thereby the possibility of making a mistake due to a limited possibility of human eye. Visual quality requires uniform lighting with specific requirements on intensity and reflection. More reliable visual control of better quality is realized by automated systems using robotic vision. Different geometries of various halogen lighting are analyzed by simulated models of ceramic tiles illumination. An increase in the number of halogen sources leads to increase ceramic tile illumination. Illumination uniformity on surfaces is analyzed and managed by a different geometry of halogen spotlights. The physical ceramic tile illumination measuring is performed using the photometer for every illumination model in operating conditions. The level of RGB light component is read from pictures made by a digital camera which increases with the increment of ceramic tile illumination. The necessary illumination quality and uniformity could be achieved by an increased light sources number that determining the construction of lighting hardware. The good illumination quality is necessary due to fault detection methods based on several algorithms based on pixel intensity comparison.