Research In The Method Of Intelligent Conceptual Design Based On The Extension Theory

With the sponsor of National Natural Science Foundation (No: 50175103) and National 863 project (No: 2002AA411110), this paper studies the key-skill of extension intelligent design of mechanical product theoretically and practically. Based on overview of the current research in conceptual design, it applies extenics, fuzziness theory and optimization technology, and reveals the creative rule in earlier state of conceptual design, and explores a creative and dialectical formal, modeling method, namely extension method of conceptual design. In conceptual design, to the scheme expression, decompounded and integration, optimization and solution, reason and evaluation of, it raises several new theories and methods. All of these have significant theoretical and engineering value to solving the bottleneck of intelligent conceptual design. The primary results of this paper are as follows:In the paper, it describes the earlier knowledge state of conceptual design with extenics, such as function, principle, layout, figure, structure and so on, and then sets up qualitative (basic element extension nature, etc.) and quantitative (correlation function, etc.) extension knowledge expression model. It applies extension methods to express the further knowledge of design. It forms extension expression of intelligent conceptual design, and brings out an effective way to modeling and intelligentzing conceptual design dialectical thought.The paper raises a qualitative and quantitative combined conceptual design method, which is based on multi-stage rhombus thought model. According to its divergent-concentrate-redivigent- reconcentrate nature, it sets up a product design method of multi-stage rhombus thought model. According to matter-element extension nature, it carries on multiplicate design with divergent thought, and works out the optimization design with the all method, such as the true and false information, the concentrating fuzzy mind, and the extension correlation function with quantitative method, etc. The feasibility has been proved with the conceptual design in tools storage of machining center.It is hard to describe the shortage of design knowledge in the combination of qualitative and quantitative with the case based reasoning method. The paper raises the extension case based reasoning method through disposing the design information matter-element and matter-element relationship, and changes unknown problem into known one. The application of the extension matter-element character has extended or constringed solution space effectively. With the method of extension innovation reasoning, it analyses the design rules and constrains relationship of a reducer, create an extension base base, realizes all the process of extension case reasoning and proves the feasibility of extension cased reasoning effectively.It is hard to solve the problem of earlier state design optimization. The paper sets up the multi-objective fuzzy matter-element optimization model, changes the regularized correlation function into fuzzy membership function. Setting up the fuzzy matter-element divergence tree model, it proves the feasibility of fuzzy matter-element method in scheme optimization of mechanical products with correlative...