The non-closed parts optimal fitting method based on curvature Hausdorff distance using 3D non-contact measurement points

Abstract

Auto-body panel fitting is an efficient way to improve dimensional quality and to give a better impression to the consumers. Optimal panel fitting has been studied by many authors, and the proposed optimization models mainly concerned the optimized fitting position for two closed parts. The fitting problem of the front and rear parts of a car is different from the closed parts fitting problem, because the fitting parts are non-closed. The purpose of this research was to develop systematic and efficient methods for optimal fitting of non-closed parts using 3D non-contact measurement points. B-spline curve fitting was employed to obtain fitting boundaries from point cloud data. A new fitting model for non-closed parts based on curvature Hausdorff distance was proposed to obtain the optimal fitting quality. The validity of the minimal curvature Hausdorff distance corresponding to optimal fitting quality was verified by a practical demonstration. A practical fitting case of the hood, headlight and fender of a car was conducted and optimal fitting quality was achieved. The results of this research will enhance the understanding of the optimal fitting of spatial curves, and help systematically adjust the non-closed fitting parts.