3D optical measuring technologies for industrial applications

Abstract

Automatic dimensional inspection of 3D articles with high resolution and productivity is an urgent problem for industry. It takes solving some measurement basic and applied tasks. Using the optical inspection methods, it is essential to take into account the influence of 3D bodies' extension on their Fraunhofer diffraction pattern and images. This influence strongly depends on the configuration of illumination, which therefore is fundamentally important. The solution for diffraction phenomena by volumetric slit under inclined plane and spherical wave illumination has been represented. The obtained results can be applied for investigation of formation and high-frequency filtering images of 3D bodies of constant thickness. Ensuring the safety and high operation reliability of nuclear reactors takes 100% inspection of geometrical parameters of fuel assemblies, which include the spacer grids performed as cellular structure with fuel elements. The required spacer grids geometry of assembly in the transverse and longitudinal cross sections is extremely important for maintaining the necessary heat regime. A universal method for 3D spacer grid inspection using the diffractive optical element, which generates as the structural illumination, a multiple-ring pattern on the inner surface of a spacer grid cell is investigated. Using some diffractive optical elements one can inspect the nomenclature of all produced grids. Experimental results for semi-industrial version of spacer grid inspection system are presented. A structured light method and testing results of pilot system for noncontact inspection of wire wear and its defects for train electro-supply network are given and discussed.