The Qualitative Description And Transformation Of The Functional Requirements In Product Conceptual Design

Conceptual design is the most crucial step in the product design cycle, more and more scholars into the the study of conceptual design. Conceptual design is used to convert the demand to the product, so the treatment of demand is very important. In the phase of conceptual design, known information is usually uncertain and ambiguous, andcan not be accurately described by a model. By using QFD method, some demands which given by the user canbe convertedto each technology characteristics requirements in the entire product design cycle, and for designers to use.One of the main input of QFD approach is a reasonable representation of demand, In the demand acquisition and modeling methods, tree and diagram methods can be a good demand for a functional and structural requirements covered in the product, but when given the conditions of demands, it is not proper. Using ontology axioms can solve this problem well.The paper has been further understanding from abstract view of conceptual design process, emphasizing the importance of proper handling needs comprehensively. After having a preliminary understanding of modeling ontology, then combined with product quality attributes and modeling of the tree. Introduce the steps to build body mass in detail, and then build constructed representation of mechanical products. Reducer part to demand, for example, proposes two types of major problems encountered when processing demands. The first constraint, in the establishment of the body, will create constraints between various concepts, this article do the does transformation of demands which not meet the constraint. Second is the uncertainty classification. When establish the body, we according to the abstract quality of the product attributes and classification, and the ambiguity of the definition of the concept of the border, resulting in classification appears ambiguous situations. Needs analysis for these two issues, on the basis of learning and summarize the knowledge and application of fuzzy mathematics, based on the fuzzy clustering theory and mathematical methods to introduce the concept of membership function of the design, a good method can deal with the demands that not satisfy the constraints and attribute categories appear fuzziness situation. By design the appropriate knowledge representation, based on the needs of the most primitive quality attributes are classified and representation. After processing is complete on demand, in order to get the key technical characteristics of the product design, the need for demand to sort and calculate the weight of the individual needs, thus combining the advantages of AHP method to calculate the right weight for each requirement. Thus, the combination of QFD house of quality matrix, we get the key technical requirements for product design, and throughout the product design, the user has finished the conversion to product designers. Finally reducer design issues, the use of mechanical products, said the body needs to get a clustering results with the corresponding mathematical methods to solve the problems in the reasoning process. In QFD house of quality, combined with expert knowledge of experience, has been designed for the needs of major reducer sorting and key technical requirements to complete the demand from the user to the technical characteristics of the conversion.