A measurement method of the belt grinding allowance of hollow blades based on blue light scanning

Abstract

The high performance of aero-engines requires light-weight aero-engine blades, so hollow structures have been widely used in aero-engine blades. At present, the measurement of aero-engine blades is mainly carried out with coordinate measuring machines (CMM). This method can measure most of the aero-engine blades through direct contact. However, the complex surface, the chord width, and the large torsion of the profile of a hollow blade lead to measurement difficulties. In addition, the surface contact machining characteristics of belt grinding largely depend on the known data of the detected surface, so the CMM cannot efficiently obtain the belt grinding allowance data of a hollow blade and the application of hollow blades is limited in aviation. In this paper, a new method of obtaining belt grinding allowance data of a hollow blade based on blue light scanning was proposed according to complex surface structural characteristics of a hollow blade and surface contact characteristics of belt grinding. The point cloud information of a hollow blade was obtained through blue light there-dimensional scanning and then matched with an improved ICP algorithm considering the curvature change of the hollow blade, so as to obtain the belt grinding allowance of the hollow blade. Finally, the measurement method was verified by the belt grinding experiment with the hollow blade. The experimental results confirmed that the improved ICP algorithm was more accurate and that the measurement method could obtain the allowance data of the hollow blade.