Study Of Design Reuse Method Towards Complex Product System (CoPS)

Complex Products and System(CoPS)is a kind of equipment which have characters with large scales,technology intensive,long development cycles,etc.As a result,CoPS needs support of knowledge and sources of many fields.However,due to chaos of management,information isolation,product designer turn-over,it is easy to appear the phenomenon that mechanic structures that have same functions but have different designs,which would reduce the design reuse degree.This will cause huge problems with the design and manufacturing cost increasing,as well as development cycles extending.In this thesis,the history researches and applications are introduced,and then structure similarity model and complex network with weights are set up.Finally,the effectiveness and efficiency of the methods are proven by realizing them in real engineering case study.In the first part of the thesis,the key problems of improving design reuse in different degrees design layer is analyzed.Firstly,four different layers of spare parts are separated based on different functions,operational principles,parameter values,and interfaces.Then,the commonness and differentness of spare parts in each level are elaborated.Finally,journals for solutions of different heterogeneous problems are reviewed.In the second part of the thesis,the partition principle and design reusing method of the different designs which have different operational principles are analyzed.Firstly,in order to recognize heterogeneous spare parts with same function,the structure similarity model is applied to judge the similarity between two structures.Then information axiom is applied by setting the minimum customer information as a threshold,and the design reuse level and customer fulfillment of the products was introduced in the object function,in order to an optimization model was build up.In the third part of the thesis,design reuse method of parameter series is studied.Firstly,parameters similarity of different spare parts are defined,and the similarity is used as weight of edges in the complex network.Then the function parameters(across the function module)are re-clustered by using GN clustering algorithm.Finally,the usage of different parameter schemes are set as the weight when calculating the clustering center,and a new parameter series is acquired which has less parameter schemes and higher design reusing degree.In the fourth part of the thesis,a case study is demonstrated.Based on introduction of reuse method in previous chapters,the method is took practice in the case of crawler crane portfolio,and the feasibility and effectiveness of the methods are approved.In this thesis,spare parts are separated according to different layers of design of complex product system and the common and different characters designs between spare parts in each layer are summarized.Based on these characters,methods of design partition and methods of improving reuse of product designs has been raised.Finally,these methods are took practice in the use of real engineering case,and the rationality as well as efficiency of the methods are proven.