Patent ID: 6711530
Filing Date: 2004-03-23
Classification: G01B,G06T

Abstract:
A method for evaluating a shape error of a free curved surface comprising:dividing an original curved surface S into up to six curved surface units by combinations of signs (+, 0, âˆ’) of a principal curvature (k1, k2) in each point on said curved surface; associating a distorted curved surface Sâ€² with said original curved surface S and dividing it into curved surface units having the same boundary by projection along normal vectors of the curved surface S; calculating an average normal vector for each curved surface unit with respect to said original curved surface and said distorted curved surface; obtaining â€œa bent componentâ€  and â€œa twisted componentâ€  in all the combinations of pairs of different curved surface units with respect to said original curved surface and said distorted curved surface; and calculating a difference between â€œthe bent componentâ€  and â€œthe twisted componentâ€  in each combination in said original curved surface and â€œthe bent componentâ€  and â€œthe twisted componentâ€  in each identical combination in said distorted curved surface.