An Algorithm of Form Deviation Calculation in Coordinate Measurements of Free-Form Surfaces of Products

The article presents the new method of form deviation calculation in the case of coordinate measurements of free-form surfaces of workpieces. The proposed algorithm of form deviation evaluation is based on the interpolation process of corrected measured points. Corrected measured points are the results of probe radius correction process applied in the coordinate measuring technique. The interpolation is conducted by using of the Lagrange and Chebyshev methods. The developed algorithm of deviation calculation can be implemented in most commercial software cooperating with a coordinate measuring machine. In the article the results of numerical and experimental investigations connected with the proposed algorithm are presented. The numerical investigations concern the simulation of contact coordinate measurements of products, which can be conducted on a coordinate measuring machine. The measured products are composed of free-form surfaces characterized by various curvature and consequently various degree of geometric complexity. The experimental investigations were conducted in order to verify the results of simulation studies. The presented method improves the accuracy of measurements of free-form surfaces of products.