A-DESIGN - AGENT BASED ADAPTIVE CONCEPTUAL DESIGN

INTRODUCTION | ITERATIVE SEARCH PROCESS | MULTIOBJECT DESIGN SELECTION | MULTI AGENT ARCHITECTURE | FUNCTIONAL REPRESENTATION | A DESIGN AS SEARCH STRATEGY | TEST RESULTS | DISCUSSION AND CONCLUDING REMARKS

FUNCTIONAL REPRESENTATION

It is necessary in any computational process to have a formal description of the artifact being manipulated, created, or optimized. Traditionally, in engineering optimization, the representation is a simple vector of fixed length, set prior to execution, containing variables representing different physical attributes of a design. The perturbation of this vector, x, is often done either randomly or through knowledge of previous evaluations of x. In the case of genetic algorithms, for example, the x is often expanded to a bit string in order to represent a genotype encoding. The manner in which the string is manipulated can have unpredictable or far-reaching effects in the phenotype or physical construction of the design. The unsystematic changes that can result by manipulating the design encoding make logical modification of the design state difficult.

It is for this reason that we develop a description of the design state that is most natural to modeling the actual device and not a description which is merely beneficial for the manipulation and creation of designs through computational methods. As will be seen in Section 5.2, an electro-mechanical representation is developed to model a range of electro-mechanical devices and does not depend upon the manner of constructing or altering designs. Allowing more freedom in constructing computational representations, be it through data structures or variable length vectors, allows design synthesis to be more general without the restrictions imposed by the construction process. The drawback of having a more general design description, however, is the need for more involved techniques for configuring designs, hence agents are used to act as a buffer between the iterative process and the representation.