Abstract
This paper presents a constraint management methodology, which facilitates tradeoff studies during conceptual design. This approach represents design models as constraints between variables, and uses the resulting constraint network to automatically derive computational procedures for performing user-specified tradeoff studies. By decomposing large constraint networks into smaller pieces that can be solved robustly, this approach can solve extremely large systems of non-linear equations present in practical system models. Design Sheet is a software implementation of this methodology; it allows the designer to interactively develop models, flexibly define tradeoff studies, and quickly explore large areas of design space to study how the different performance and cost criteria tradeoff with respect to one another. Design Sheet has been used on practical applications ranging from the system-level design of spacecraft using combined performance and cost models to the preliminary design of automotive bearings. This paper demonstrates the unique capabilities of Design Sheet in performing design tradeoff studies, using a thermal imaging system performance model developed for the DARPA MADE program.
Terahertz imaging system performance model for concealed-weapon identification