Research And Development Of Central Database System And Feature Modeling System For Mechanical CAD

The database technology is an important part of that of the computer software. The engineering database provides the information basis for the CAD/CAM integration when it is applied in CAD and CAM. Feature Modeling technology is one of the forward research areas of CAD and is the necessary way to realize the CAD/CAM integration. Through the research on database application in CAD by the author, a concept named Central Database (CDB) is posed, a CDB is planned and built, a Central Database Management System (CDBMS) and its development tools are developed with Object Oriented Design (OOD) method on the basis of AutoCAD SQL Interface (ASI), and the Object Oriented extension of the rational database system is researched. The CDB system has enhanced the functions of the CAD software, improved the on-line help ability on product design, and supported the development of CAD applied software. With the support of the CDBMS the author has brought up a general Object Oriented model of product features, planned and realized a general-purposed and open Feature Modeling (FM) system using Object Oriented Design method. Such functions are provided by the FM system as creating features, inputting feature information, fetching features and creating feature report forms. The Central Database system and FM system have been applied in a CAD/CAM software system named XTMCAD. Feature models of products (parts) can be built by using the FM system. Under the management of the CDBMS the models can provide useful information of products or parts to the processes of CAD, Product Data Management (PDM), CAPP and CAM, and then can give service to the CAD/CAPP/CAM integration.