Precise 2D and 3D Hybrid Measurement of Drill Bits with Complex Geometries

Abstract

Drill bits with complex geometries are pivotal role as essential tools widely applied in high-performance manufacturing processes, particularly in aerospace and related industries. However, the precise measurement of the geometries of such cutting tools is quite challenging owing to their complex reflective properties, surface morphology, and numerous parameters within small dimensions. In this paper, we present an investigation of the effects of lighting and processing marks on visual measurement and propose a correlated fusion vision dual-platform with high accuracy and efficiency. First, a comprehensive calibration model and method that considers installation errors for bi-telecentric imaging is proposed. Then, improved methods for robust and precise two-dimensional measurement are presented, including an adaptive illumination method for high-contrast imaging and an interactive measurement algorithm for accurate feature extraction. Furthermore, a novel enhanced focus measure (ITene-Gabor) that incorporates both grayscale gradient and frequency information is proposed for high-quality three-dimensional topography reconstruction. Finally, we detail experiments and accuracy verification performed on two typical complex drill bits with sawtooth features. The experimental results demonstrate that the developed equipment achieves measurement deviations of less than 3 μm for length and 0.5° for angle as compared with a commercial microscope. The measurement efficiency averages 30 s per parameter, confirming the high accuracy, effectiveness, and reliability of the proposed method and system for measuring all drill bit parameters. The correlated fusion vision dual-platform and measurement methods also have the potential to be extended to other complex industrial products and can serve as a basis for developing universal measurement equipment.