Method for nesting a computer model of a part with a computer model of a fixture

Abstract

A method of nesting a computer model of a part ( ) into a computer model of a fixture ( ) useful for situations where the original positions of the part and fixture are completely separate and for situations where the respective part and fixture surfaces overlap. The model of the fixture is first inset by a distance D sufficient to eliminate any overlap between the modeled surfaces. The minimum normal distance segment ( ) between the inset fixture surface and the part surface may then be determined using standard CAD system capabilities. A vector is then constructed having a length D beginning at the minimum distance point on the inset fixture surface ( ) and extending in the direction of the minimum normal distance segment ( ) to a point ( ) on the original fixture model surface ( ). The minimum distance segment between point ( ) and the surface of the part ( ) is then determined to identify a point ( ). The respective point pair ( ) is recorded. Similar point pairs are recorded for each degree of freedom of movement between the part and the fixture. An orthonormal transformation matrix is then identified for moving the part to a position that minimizes the aggregate distance between the respective point pairs. This process may be repeated until the aggregate distance satisfies an acceptance criteria, whereupon the part model is deemed to be nested into the fixture model.