Functional Requirement Analysis And Functional Design Method For Adaptable-function Mechanical Products

Adaptable-function machine is a multi-function machine,which can realize the conversion between various functions by replacing and adjusting the relevant components according to the actual requirements.It has important practical value.The research can improve user's satisfaction and enhance product's competitiveness effectively on the conceptual design of the adaptable-function mechanical products.In view of the existing problems in the current research,this thesis focuses on the research of functional requirements analysis and functional design for adaptable-function mechanical products.Firstly,this thesis researches the functional characteristics of adaptable-function mechanical products.By the means of functional semantic representation and the decomposition model of function tree,and by analyzing the functional characteristics of each function,the functions are decomposed in the adaptable-function mechanical system.By introducing the black box model and the related concepts of series-parallel connection,the functional chains of variable the adaptable-function machines are structured to help analyze the input and output streams and similarity characteristics among the chains.,which provides foundation for the subsequent researches.Secondly,the functional requirement analysis is studied,which is intended for helping designers obtain the information of user's functional requirements more accurately.For the functional requirements proposed by the users,the questionnaires based on KANO model are employed and investigated according to the characteristic of user groups.The information parameters,such as demand category,weight and satisfaction of users' functional requirements are obtained by quantitative calculation in order to guide the design and improve the user's satisfaction with the products.Finally,the feasibility of the method is verified by a multi-function tool.Thirdly,the method of transforming functional requirements into design structure is studied by means of case-based method.With the help of FBS theory and database management,some typical functions and structures of adaptable-function mechanical products are input into the design case database in the way of feature coding for organization and management orderly.At the same time,the acquired functional requirements are also processed by feature coding,and the target casestructure is retrieved in the case base according to the similarity and final association between the corresponding codes.The optimal case solution is selected to lay the foundation for the realization of the functional design of the case solution during the design process.Finally,the method of functional component identification and interface design is studied about the adaptable-function products.To this end,the coupling analysis is carried out between the set of case solution and existing system functions,and the final design method is determined by the calculation of coupling degree and analysis principle.Then the function chain expansion and semantic generalization process are used to identify the key components and non-shared components by the exploration of the similarity between the case solution and the system function.Subsequently,the interface design is guided according to the interface design principles between the non-shared components and the key components,and the final design is completed through evaluation and optimization.Finally,the feasibility of the scheme is verified by the functional design of the adaptable-function micro tillage machine.