Illumination system optimal design for geometry measurement of complex cutting tools in machine vision

Precision geometry measurement of complex cutting tools has a significant impact on the machinability of components in the industry. However, acquiring high-quality images in machine vision is a challenging problem due to the large slope and complex geometry. In view of the vital function of illumination, this paper proposed a method of optimal design for the LED array. First, the calculation model of irradiance distribution on the measurement plane is established, and the properties of the reflected light from the surface of cutting tools are analyzed based on the BRDF theory. Then, the optimal parameters are solved through the specific algorithm flow for the LED array design. Finally, a flexible LED light source is fabricated with the optimal parameters for different features of the cutting tools and used in the measurement. The measurement results show that the error of the optimized light source is less than 1 % , and compared with the off-the-shelf light, the measurement accuracy is improved by 9.5 % on average. Moreover, this method also presents the potential applied to other complex objects.