Research On Feature Modeling Theory And Automatic Solution Technique For Conceptual Design Of Complex Function Products

After a systematic analysis of the background and state-of-the art of research in conceptual design, course, method and strategy of conceptual design based on cyclic mapping are researched, aiming at solving some crucial issues in this research area. The primary contributions are as follows.First, the frame of design catalogue for principle solution is discussed. Design catalogue is the knowledge base for manually principle solving, as well as the foundation for automatic principle solving. On the basis of research on the demand of principle design catalogue, the frame of design catalogue based on four sub- catalogue including function catalogue, effect catalogue, principle catalogue and structure catalogue, and the structure and relation of sub-catalogue is put forward. 500 principle solutions of typical products are collected, classified and abstracted and a design catalog that includes ten kind of typical function is developed.Secondly, feature modeling and solving process of complex function is researched. On the basis of studying the process of principle solving, the feature model for complex function is established. The general solving process of complex function and the concurrent strategy of single function solving and interface feature matching are put forward. Then the nested structure of interface feature and the matching process are represented. Finally the principle solving of coin-assorter is given as an example.Thirdly, based on the fact that appending and solving auxiliary functions are always depended on solving the aim function during conceptual design phase for complex function, the conceptual design cyclic mapping model which supports cyclic solving between function layer, effect layer, principle layer and structure layer is put forward. It consists of three mapping pattern and twelve mapping relations, such as decomposing mapping, solving mapping and deriving mapping. A formal representation method for the conceptual design and/or tree that is suitable for automatic solution is putforward and the solution algorithm is discussed. Finally the conceptual design of a woodworker is given as an example.Finally, based on the above researches, a computer aided conceptual design automatic software system named CACDS is developed based on the cyclic mapping model, which is composed of four sub-system, i.e. input sub-system, conceptual solving sub-system, output sub-system and knowledge-base management sub-system. The software can integrate principle solving with functional structure solving and can support conceptual design of creative products in a smooth way.