Proceedings of the ASME 1998 Design Theory and Methodology Conference
Atlanta, Georgia, Sep. 13-16, 1998, Paper number DETC98/DTM-5646.
Abstract
In preliminary vehicle structure design, as in all preliminary
engineering design, many important decisions are made informally on
the basis of imprecise information. Concerns of styling and
manufacturability, for instance, can carry great weight in the design
process although they are not modelled by any formal analysis.
The Method of Imprecision, or MoI,
is a formal method for incorporating imprecise information into a
design process, and
helps to make preliminary decisions on a sound basis.
In a demonstration of the MoI prepared for VW Wolfsburg, concerns
of manufacturing, styling, parts availability, and design were
incorporated with the engineering analysis of the structural stiffness
of a VW Rabbit. The results show the usefulness of the method in
trading off these
conflicting attributes, including styling preferences and engineering
requirements.
Any analysis involving more than two design variables must contend
with two difficulties, the exploding need for computation, and the
problems of displaying results in several dimensions. The MoI uses
optimization and
approximations, when feasible, to address the first difficulty, and an
interactive graphical tool for preference display was developed and
applied here to address the second.
Keywords: Industrial applications of DTM; Vehicle Structure Design;
Design Methods and Models; Design
Representations; Computational Methods of Design;
Fuzzy Sets