Parts Design Reuse Methods With Coarse-Grained Double-Network-Mapping

Design reuse of product has become a hot research field outside China since the late20th century. Its main idea is to maximize the usage of the resources, meanwhile to support the rapid innovative develop of new products by mining, managing and utilizing the existing design resources of enterprise with the help of computer technology.Design reuse can effectively shorten the development cycle of new product, reduce design costs and improve design quality.Parts design reuse is an important component of design reuse.It has been reported that when designing a new product, about40%to50%parts of the old products are reused and about30%to40%are slightly modified.Ninety nine percent of the enterprises in china are the Small and Medium-Sized Enterprises (SMEs),and the GDP of SMEs has exceeded that of the large enterprises. Therefore, the parts design reuse technology is of great significance for the SMEs.However, the current design reuse mainly focuses on mass customization for the large enterprises,while most of SMEs are difficult to meet the requirements on mass customization due to the limitation in finance and human&material resources.The main obstacle is that the existing tree-structure-based parts library can hardly describe the relevant connection among different parts, while building a new parts library requires large costs such as manpower and money. Therefore, the present problem is how to realize the design reuse based on the current parts library.This dissertation, under the support of National Natural Science Foundation of China, presentes parts design reuse methods with coarse-grained two-network-mapping to deal with several key problems of parts design reuse for SMEs.In accordance with the national conditions of China, study on parts design reuse methods for SMEs is undoubtedly an important project worth researching.This paper presents the following major tasks of the study:Firstly, we propose a parts design reuse method with coarse-grained two-network-mapping. Based on the SMEs'existing graphic parts library with relation tree, the method adopts a semantic web to construct a parts knowledge network with coarse structure.This coarse parts knowledge network is used to describe the main design information(such as the number of gear teeth and gear modules) and their relationships among different features and different attributes,between features and attributes.Therefore,the associated relations between different parts are built. The existing graphic parts library of the enterprise is taken as a knowledge network with grained structure.Furthermore,a mapping relation between the two knowledge networks is established to reuse the parts design knowledge.The key technologies of acquiring the knowledge of CAD model of parts are also discussed, including the acquisition of assembly relation between parameter and geometrical information of CAD model, the data storage and so forth.Secondly, a parts knowledge similarity retrieval algorithm based on coarse-grained two-network-mapping is presented. According to the required retrieval knowledge for parts reuse of the SMEs, we establish parts design reuse networks with coarse and grained structure respectively, and propose a part similarity retrieval algorithm based on the mapping between the two networks.The similarity calculation includes the computing between definition similarities,value similarities, relation similarities and the estimation method of different similarity weights.Finally, the retrieval algorithm is validated and demonstrated by an example.Thirdly, we present a parametric design resource reuse method for parts design based on web service.The proposed framework borrows the ideas from component model of software reuse, such as reuse service,separation of interface and realization procedure.The reuse framework for parts can be divided into three layers:the design interface layer, the design service layer, and the design result layer. Users log onto the design interface layer on the user terminal and complete corresponding design by driving the shared design reuse templates on the design service layer of the server terminal.The design service layer consists of a series of service templates for parts design use to provide the following functions:3D solid modeling, finite element simulation and other design procedures.The design result layer provides and displays solid models, the optimizied data and so on.The propoposed method can provide the shared design resources for the SMEs and extend the range of design knowledge reuse for SMEs.The above works are hoped to promote advance in the theory and method of parts design reuse for SMEs and to improve the product design quality and efficiency for the SMEs.It is also expected to promote the level of the product knowledge design and informatization.