OPTIMAL LOCALIZATION OF FREE-FORM

SHAPED PARTS IN PRECISION INSPECTION

XU Jinting^{1, 2}  SUN Yuwen³  LIU Weijun¹

(1.Key Laboratory of Advanced Manufacturing Tech-nology, Shenyang Institute of Automation,

Chinese Academy of Science, Shenyang 110016;
2. Graduate University , Chinese Academy of Sciences, Beijing 100049;
3. School of Mechanical Engineering, Dalian University of Technology, Dalian 116024 )

Abstract: Optimal localization of free-form shaped parts is a key issue in precision inspection. Aiming at the problems on estimate of the initial transformation and the calculation of closest points, an effective and exact localization method is presented. First, this method establishes the corresponding relationships between two free-form surfaces with constraints of angle and distance by means of the surface features of the Gaussian curvature and the mean curvature. Then the rough localization is realized. Using the robust arithmetic for multivariate Bernstein-form polynomials, a novel algorithm to calculate closest point is proposed. An improved iterative algorithm is used in the exact adjustment of localization to ensure the global optimization. Experiment results demonstrate the feasibility of the proposed method.

Key words: Precision inspection Rough localization Closest points Exact localization

CLC No: TP391

国家自然科学基金资助项目(50405044). Received 20060718, received in revised form 20070122