Research And Application On Key Technologies Of Modularization For Complex Products And Systems

As a burgeoning concept derived from the large technological systems, the Complex Products and Systems(CoPS) are playing a vital role in the area of engineering equipment, aerospace et al., which are all preferentially developed inland. With the science and technology advancements, the evolution of the(sub-) systems in CoPS is accelerating, the new customer requirements are continuously emerging, and the existing customer requirements are persistently changing. All the above objective factors request the high speed increasing of the CoPS R&D efficiency to reply to the complex and fickle market environments.The existing researches on CoPS mainly focus on the brand new CoPS design and development process such as concept interpreting, characteristics analysis, innovation mechanism exploring and R&D-related operation management. Somehow, the research on enhancing the redesign efficiency with increasing the knowledge reuse and modification ration is extremely absence. Fortunately, modular design theory is extensively applied in the mass customization, and it is an effective framework to improve product redesign ration by standardizing product architecture and design variation. Compare with the traditional MC-products, the CoPS have two main characteristics: high complexity(function complexity and physical structure complexity) and prominent heterogeneity(function heterogeneity, principle heterogeneity and physical heterogeneity),nevertheless, the traditional modular design theory and approaches could not applied in CoPS design effectively without considering these characteristics. Driven by advancing the standardization of CoPS function and physical structure, this study proposes two main scientific issues: modular architecture conducting and module parameter values planning for CoPS. The emphasis of this study is to research three key technologies of CoPS modular design: the module partition technology, module partition scheme evaluation technology and module parameter values planning technology. The aim of these researches is to facilitate the evolution of CoPS architecture from the integrated architecture to the modular architecture, to enhance the design knowledge reuse ration and redesign efficiency. The main research contents are as follows:(1) The concepts and characteristics of CoPS are introduced and concluded respectively, the literatures and researches on CoPS and modular design theory are reviewed, the shortage and problems within the existing researches on CoPS design theory, especially on the CoPS modular design theory, the key technologies of CoPS modular design including module partition technology, module partition schemes evaluation technology and module parameter values planning technology are concluded, and the insufficient in related researches is reviewed.(2) The module partition approach for CoPS based on the weighted complex networks is proposed. Firstly, the elimination approach based on incidence matrix for the function and physical heterogeneity of CoPS is proposed. Secondly, to construct the CoPS components weighted complex network, the components and functional and physical relations between components are mapped to the vertices and edges of the network, the quantification approach for functional and physical relation degrees is proposed to weight the edges. Thirdly, the modified Girvan-Newman(GN) algorithm is introduced to establish the module partition of CoPS, after which, several module partition schemes with different modularity are obtained, and these schemes are the inputs of the following module partition schemes evaluation.(3) The module partition schemes evaluation approach for CoPS based the interval-valued intuitionistic fuzzy set is proposed. The evaluation indices are concluded based on the product life-cycle theory, the weights of the evaluation indices are calculated based on the correlation coefficient standard deviation of evaluation indices. The interval-valued intuitionistic fuzzy set is introduced to deal with the fuzziness of evaluation data given by the evaluation experts. As the interval-valued intuitionistic fuzzy number is a sort of interval number, the Karnik-Mendel algorithm is utilized to achieve the mathematical calculation. The rank order of the module partition schemes is obtained under the TOPSIS framework, and the interval-valued intuitionistic fuzzy cross entropy is constructed to measure the relative deviation between interval-valued intuitionistic-scheme and PIS and NIS. Then the following module parameter value planning could be implemented with the obtained optimal module partition scheme as the input.(4) The module parameter values planning approach based on the customer requirements distribution is proposed. After the module-customer requirements responding network model is established, the module parameter values planning problem for CoPS is abstracted to three issues. Firstly, the value range of the module parameter is obtained based on the customer requirements investigation and analysis with the help of QFD. Then the customer requirements are clustered with fuzzy clustering method, the optimal clustering schema is obtained by the clustering validity index(CVI), the number of the module parameter values is equal to the cluster number of the customer requirements. Lastly, the customer requirements distribution regularity is extracted by obtaining the customer requirements cluster centers, and then the module parameter values distribution regularity can also be obtained by synthesizing all the related customer reqirements regularities. With the value range, number of values and values distribution regularities, the parametric module portfolio of CoPS could be constructed.(5) The research achievements of this study are implemented in a typical CoPS to emerge an application demonstration. The large tonnage crawler crane is used as the application object, and the proposed framework and approaches are implemented in its modulr design process including the modular product architecture constructing and moudel parameter values planning, and the former includes module partition and module partition scheme evaluation. The feasibility and effectivity of the proposed framework and approaches are elaborated by the case study.This study proposes a thorough framework for the modular design of CoPS, provides technologies and approaches for the modular architecture constructing and module parameter values planning of CoPS, lays a foundation for the following research of this topic, and with the enterprise practice, implements the proposed approaches to the large tonnage crawler crane modular design process. The case study is derived from a cooperation project, and the application received the recognition of the enterprise.