A Study on a Correction Method for the Position Relation Matrix Formed from 3D CAD Data

摘要

In PLP (Prototype-less Production), the position relation matrix, which is a table of 6 direction position relations (x-, x^+, y-, y^+, z-, z^+) for every pairs of parts of a product, is used to derive assembly procedures. The previous method can automatically form the position relation matrix from 3D CAD data, but some of the relations of the pair need to be corrected manually. This study aims to present a correction method for the matrix. The method consists of 3 steps. For each pairs in which parts cannot be disassembled by the previous method, firstly the initial position of one of the parts is shifted and the position relation is re-derived. When the non-disassembly pairs still remain, secondly, for the each pair, it shrinks one of the parts and then re-derives. Thirdly, for the rest of the non-disassembly pairs, it expands one of the parts and then re-derives. The method is applied to a product of 111 parts, and the effectiveness of the method is verified.