Adaptive Drilling of Film Cooling Holes of Turbine Vanes Based on Registration of Point Clouds

Abstract

The manufacture of film cooling holes on turbine guide vanes of an aero engine suffers from the contour errors resulting from a casting process. It is therefore necessary to adjust positions and orientations of cooling holes for each vane. This paper proposes an adaptive compensation machining method based on a combination of a principal component analysis iterative closest point (PCA-ICP) registration method and an orthocenter mapping method. Firstly, a registration is carried out between an ideal point cloud and a measured point cloud by a laser measurement machine to obtain a transformation matrix. Then, the exit center of a cooling hole is obtained by an orthocenter mapping method. Simulation results show that the machining errors of vanes can be improved from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.1 mm to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.03 mm. Machining tests show that with a combination of the PCA-ICP registration and orthocenter mapping methods, the cooling holes are drilled adaptively to meet the machining requirements.