A New Method on Estimating Free-form Surface Profile Error of Blade

As the blade parts must conform to accurate shape and precise size, estimating the three-dimensional profile error of a blade is absolutely necessary. This paper proposed a new method to estimate free-form surface profile error integrating application of point cloud processing technology and iterative closest points (ICP) algorithm. A set of point cloud data, converted from a set of 3D profile measurement data of a blade acquired by laser scanner, can be aligned to the point cloud extracted from the blades CAD model. Then, calculating all correspondence points distance along normal direction between the correspondence points, the maximum value is found out and twice this value taken as surface profile error. Simulation example indicates that the result worked out by this method is very close to the theoretical result for the problem to solve transformation matrix. In addition, simulation experiment manifests that the maximum distance along normal direction between the points in measurement data and their matched closest points in the design model data is shorter than the direct distance.