Research On The Function Analysis And Combinatorial Design Methodologies Of Mechanical Systems With Adaptable Functions

Mechanical systems with adaptable functions belong to a category of multi-function machines, which are capable of delivering different functions by adjusting or replacing one or a few of their structural components. Because of some specific strengths, such as compact structure, wide applicability and easy to upgrade, they have great marketing prospect.This thesis takes the mechanical systems with adaptable functions as the research object. Firstly, it analyzed the coupling of adaptable functions from the aspects of structure and behavior. On the view of structure, it investigated the direct association and indirect association between adaptable functions and components, constructed the complete incidence matrix between adaptable functions and components, proposed the concepts of functional coupling, component influence and net component contribution, and quantified them. On the view of behavior, it analyzed the behavioral process of each adaptable function, established the generalized directed graph model of behavior structure. Based on the theory of generalized sets, it quantitatively analyzed the functional coupling. At the same time, it used the adaptable-function juicing machine as an example to explain the feasibility and significance of the described methods.Subsequently, the thesis studied the behavioral process of the transformations among adaptable functions. It defined a concept called “key behavioral state”, which is used specifically for the adaptable-function machines, built a weighted digraph model about the behavioral process of the adaptable functional transformation, developed an identification matrix of the key behavioral state, presented three criteria, including the fastest responsibility criterion, the largest comfort criterion, as well as the largest degree criterion to identify the key behavioral state, while a case study of the multi-function pliers helped explain the meaning of the key behavioral state and the feasibility of the proposed methods.Finally, the thesis proposed a combinatorial design method for the fulfillment of adaptable functions. It analyzed the component similarity among different products, studied the determination process of applicable component family, summarized the solution strategy of convergence design, and recombined the component associated diagram of multiple machines to generate the scheme of the adaptable-function mechanical system, which satisfies the design requirements. At the same time, an innovative design of a brush with two functions was taken as design case to illustrate the feasibility of the described concepts and methods.