Fuzzy technology in intelligent CAD

Nowadays, fuzzy technology and intelligent computer aided design (ICAD) are two focuses in the artificial intelligence domain. In fuzzy technology, many directions are being researched, such as: fuzzy set theory, fuzzy systems, fuzzy operator, membership functions acquisition method, fuzzy optimization, fuzzy decision, fuzzy control, fuzzy knowledge acquisition and representation, fuzzy database system, fuzzy inference algorithm, fuzzy rules extraction, fuzzy knowledge based systems, fuzzy expert system, and so on. But it is seldom used in engineering design CAD systems, especially in product conceptual design. Fuzziness exists widely in product design, such as fuzziness in design data, in design decision, in design computing model etc. But particularly in product conceptual design, the fuzziness is more remarkable. The primary aim of the article is to combine fuzzy technology with CAD technology to elaborate the advantages of each of them. The paper discusses the influence and disposal methods of the fuzziness and uncertainty in the product design, and gives a model of knowledge based fuzzy CAD systems and examples about aircraft preliminary configuration design