Determining parting direction based on minimum bounding box and fuzzy logics

Abstract

This paper describes both an algorithm for locating the minimum volume bounding box of three-dimensional CAD models and a fuzzy weighting scheme for automatic mould parting direction selection in computer-aided design of moulds and dies. When given a three-dimensional CAD model of a part, the proposed method is applied to find the minimum volume bounding box of the model. Three pairs of possible parting directions are then defined based on the bounding box surface normal. Criteria such as undercut, draw, projected area and designer's preference coded as fuzzy weighting factors are set-up for the evaluation of the most promising parting direction. Uncertainty that is assumed to be inherent in the assessments of the ratings and weights is accounted for by the proposed fuzzy heuristic. © 1997 Elsevier Science Ltd. All rights reserved.