Research On Key Technologies In Mold Dynamic Alliance Based On Web

Through the research of the development status and future trends of mold industry at home and abroad, new developing pattern of mold industry which fits for China was explored actively under the environment of manufacturing globalization. After introducing the modern computer and web technology and combining with several other advanced manufacturing theories, the Mold Dynamic Alliance (MDA) theory was suggested to change the traditional mold manufacture model, which can promote the capable of competing in the international market. Small and medium sized mold enterprises can fulfill large-scale mold project after the cooperation alliance service platform and the virtual mold manufacture group were set up by using distributed cooperation technologies. These are the original intention of this paper.The MDA is the efficiency approach for the small and medium sized mold enterprises to improve the agility and competition. The MDA based on Web was taken as main researching subject. The research work focused on the key supporting technologies of the distributed collaborative design, the collaborative process and the network manufacturing.On the subject of MDA setting-up, the optimization theory of leaguer selection, the collaborative Product Data Management (cPDM) and the Enterprise Information Portal (EIP) were discussed. The restrictions of mold leaguer selection are very complex. There are many criterions for the abilities of mold leaguers, some of which can be measured and others can not. The different criterions have the hierarchical structure. Thus, the mold leaguer selection is a kind of fuzzy optimum seeking and multi-objective decision. To solve the mold leaguer selection problem, a combined method of expert consultation approach (Delphi) and analytic hierarchy process (AHP) was used.In order to manage mold product data under MDA architecture, cPDM was defined by extending the traditional PDM to Web. The data management functions of the cPDM were described and the key requirements to fulfill the mold data management were listed and analyzed.On the aspect of service platform building, several mainstream Web portal technologies were investigated. To construct the vertical portal, a new method was suggested by adding mold related supporting components and collaborative tools. The vertical portal can offer mold technologies from dispersed mold units.On data sharing and exchanging among heterogeneous CAD model, two types of exchange model—the customized exchange interface and the universal exchange interface—were comparative studied, and finally the universal exchange model was chosen to be used in MDA. After studies of the neutral file format of STEP and its modeling language, the method of mold key features recognition and extraction based on domain semantics tags was proposed. On the one hand, the method need not change STEP file format and entity type definition, on the other hand, it can recognize and extract the key feature exactly and rapidly just by embedding mold semantics tags according to the STEP syntax. A typical mold cavity 3D model was taken for example to explain the realization procedure and algorithm. A sample program of Java APPLET was developed to execute the mold parting line recognition and extraction.In order to minimize the data volume of 3D mold model and accelerate the network transfer speed, lightweight model was adopted to realize the 3D model browsing by synchronization of distributed client. Through studies on different lightweight models from common use 3D CAD software and international consortium, the integrated lightweight model viewer was developed by using the lightweight models' API in the form of ActiveX. Leaguers can use the viewer to browse the multi-type lightweight models without the original CAD software.For integrative storage and extraction of mold data in MDA, a new file format which can be used as data exchange model and Web browse model was defined by integrating the STEP data and Web3D data into a single file. A middleware based on integral data encapsulation method was developed, which used XML DOM to accomplish the data encapsulation, parsing, extraction and revivification.With the requirements analysis of mold distributed collaborative design, a scheme of CAD command stream multicast was presented to realize the synchronized mold design. The scheme allowed the client middleware to capture the CAD command stream through macro recording interface. The command stream text would then be multicast to other remote client among the collaborative group. The above mechanism can fulfill the mold collaborative design under MDA circumstance through the network.As for mold process collaborative discussing in MDA, the technologies of sharing the 3D model visualization and interaction on the Web were studied. After comparatively analyzing the disadvantages of the desktop sharing and the screen sharing, a synchronized browsing method was put forward with the 3D transforming matrix sharing among the group. A discussing tool with the functions of multi-users sharing the model transform was developed.To realize the network manufacturing under MDA circumstance, the open architecture CNC system was studied. Through analyzing of XML format NC program from STEP-NC standard, a 3D tool path generator was developed based on the open-source code Java program. To simulate the cutting effect of mold cavity and core surface, a real sense simulation method of cutting process was introduced. Mold experts can use the method to check cutting effect of the key part. At the same time, the synthesizing skills of dynamic simulation file were also introduced.