Registration algorithm for near-net-shape blade based on multi-tolerance constraints.

A multi-tolerance constraint-based registration algorithm for near-net-shape blades is proposed for problems of small machining allowance and positioning difficulties of near-net-shape blades. A global registration model based on the tolerance constraint of contour degree and a local registration model based on the constraints of position degree and torsion degree are established under multi-tolerance constraints. The registration algorithm proposed in this paper is verified using actual measurement data of a near-net-shape blade and its nominal model, and the solution process of the registration model is given. The analysis shows that the registration algorithm based on multi-tolerance constraints can effectively improve the registration accuracy of the near-net-shape blade. Registration parameters are optimized to make the out-of-tolerance value to be zero. Finally, based on the registration results, machining experiments are conducted on a near-net-shape blade. The results show that deviations of leading and trailing edge profiles are machined within the required limits. The proposed registration method is effective to improve the machining accuracy. [ABSTRACT FROM AUTHOR]