Research On Integrated Modeling Of Modular Fixture Components Base

Computer-aided fixture design (CAFD) has gone through three development stages including interactive CAFD, GT (Group Technology)-based and Knowledge-based CAFD, and the CAFD system that aims at generating fixture configuration design. Such backgrounds enormously impel the fixture design process of being automatic. With the frequent exchanges of information in and among the enterprises, demands of applying CAFD to different CAD platforms also get more imperious. However, a drawback of current CAFD systems is that users are restricted to the special computer architecture or CAD system, application on different platforms or operating systems is restricted. Based on above backgrounds of CAFD and demands of enterprises to use CAFD in heterogeneous platforms, this paper proposes an integrated modeling method of modular fixture in which oriented-object (OO) method is taken as a core and tabular layouts of article characteristics (TLAC) and XML are integrated to build an integration modeling of modular fixture components base management system (MFCBMS). Finally, CAFD system can be used across divers CAD platforms. The main points are:(1) After analyzing the problems of MFCBMS, starting from the application and demands of enterprises , this paper uses techniques of object-oriented analysis ( OOA ) and object-oriented design (OOD) to determine the system actors and boundaries. Such, use case diagram of UML and class diagram on basic modeling as well as classes hierarchy is set up, and assisted models are also built to describe the system activity flow by activity diagram that are used to build models for operations in system objects. Thus, an integrated framework model of MFCBMS based on OO method is presented.(2) From the aspect of system data description, this paper uses TLAC-based data modeling method to pick up characteristic data from fixture components and typical structures to compose low and line of TLAC, description hierarchy is proposed according to the different data storage. TLAC provides a new mode to describe and manage fixture data, which can effectively satisfy the demands of configuration design of modular fixture.(3) On the side of fixture data exchanges in heterogeneous platforms, this paper uses XML-based method to depict data and establish the description rules of XML, mapping between CSG-based primitives and features in TLAC and XML files are built and realized. XML makes it possible and feasible for modular fixture components base to be used on web and different CAD platforms because of its extensibllity, highly structured characters, web transmission convenience, and platform independence.(4) Based on the above theoretical researches of MFCBMS, this paper adopts object-oriented language—VC++, .NET platform and database software such as SQL Server, ADO and so on to fulfill the TLAC data management, XML data description, mapping between TLAC and XML, and realizes the functions of MFCBMS framework.(5) Researches based on DOM techniques and the secondary development tools as UG, AutoCAD and ACIS are carried out. Interface sub-system based on the above three kinds of CAD platforms is developed by using XML parsing technique and the rich classes, modeling functions provided by those secondary development tools. Graphics of modular fixtures can be redrawn at heterogeneous CAD platforms, offering data sources and guarantees for the following assembling steps of modular fixture components base.(6) User interface of MFCBMS is designed to provide convenience for users to rapidly browse and query the fixture components and typical structures in modular fixture components base. The customized tools on the interface, which can satisfy user's customization demands, are provided. XML files for given fixtures, which can be used by heterogeneous CAD platforms can also be generated.