Evaluation and identification of the profile errors of complicated plane curve

The method for measuring curve profile error and principle of profile error evaluation are summarized. The geometry rule of the least condition principle for evaluating profile error of the plane curve is proposed. An efficient model and algorithm are presented for planar free-form curve profile error evaluation. The self adaptive coordination is realized between the theoretical curve and the measured subject by the process of pre-positioning rough match of the feature points and fine match. At last an example has validated the correctness of the geometry rule and feasibility of this algorithm.