Aiming at curvature change fast of blade at leading and trailing edges and the possible bending and twisting deformation after demoulding

the machining errors in the polishing of the whole blade are mainly concentrated at leading and trailing edges. A method of blade reconstruction model modification with free-form surface deformation is proposed. Firstly

the PCA method is used to achieve fast coarse alignment of the blade. Secondly; the alignment result is used as the initial value of the ICP algorithm for iterative calculation to obtain the optimized fine alignment model. Thirdly

the coordinate transformation parameters between the blade reconstruction model and the blade theoretical model are obtained by using the free-form surface deformation algorithm. Finally

the optimal parameters are used again as the initial value of the ICP algorithm for precise alignment. The results of numerical analysis show that the present algorithm reduces the absolute value of alignment error from 2.76 mm to 0.2 mm comparing with the traditional PCA and ICP secondary alignment algorithms

and the experimental results show that the roughness of the leading and trailing edges of the blade after polishing is below 0.4 μm and the contour error is below 0.08 mm

which verifies the effectiveness and feasibility of the present method.