Geometric Parameter Analysis on Three-Dimensional Reconstruction of Turbine Blade Cooling Holes Based on Multi Focus Images

The parameters of cooling holes on aerospace engine blades, including diameter, angle, and depth, critically influence the blades' cooling efficiency and overall performance. However, due to the intricate structure of the cooling holes, conventional measurement methods often fall short in terms of accuracy and efficiency. Addressing these challenges, this paper employs Shape from Focus (SFF) technology to achieve highprecision measurement of cooling hole diameters. This approach entails capturing a series of images of the cooling holes using an advanced image acquisition platform. To enhance measurement accuracy and efficiency, the Laplace operator is utilized to extract clear regions from the image sequence. This process is further refined by incorporating Region of Interest (ROI) algorithms to select pertinent data related to the cooling holes, thereby facilitating the 3D reconstruction of these features. Compared to traditional methods, this technique significantly improves computational efficiency and processing speed while enhancing the accuracy and stability of image processing. The method achieves a measurement error of less than 0.005 mm and a relative error of less than 1.5% when measuring the diameters of cooling holes, thereby providing robust support for industrial inspection and quality control. Moreover, it holds broad application prospects and substantial practical value.