A brief discussion of the content and methodology of STEP is given, and STEP based strategies for CAD/CAPP information integration is pointed out. A STEP based feature technology in which a three layer feature defini...A brief discussion of the content and methodology of STEP is given, and STEP based strategies for CAD/CAPP information integration is pointed out. A STEP based feature technology in which a three layer feature definition is included is discussed, the content of feature information is analyzed and a stratified CAD feature library is shown. On these bases, a commonly shared part information model is proposed. The architecture of the integrated CAD/CAPP system is presented.展开更多
The information integration of CAD/CAPP is one of the crucial techniques in CIM. Thispaper desicribes an integrated CAD/CAPP system which is implemented by connecting MPIM to BR-CAPP via an interface for data exchange...The information integration of CAD/CAPP is one of the crucial techniques in CIM. Thispaper desicribes an integrated CAD/CAPP system which is implemented by connecting MPIM to BR-CAPP via an interface for data exchange between them. The data exchange between MPIM and BR-CAPP is accomplished through STEP neutral file.展开更多
The geometrical and topological information of 3D computer aided design （CAD） models should be represented as a neut- ral format file to exchange the data between different CAD systems. Exchange of 3D CAD model data...The geometrical and topological information of 3D computer aided design （CAD） models should be represented as a neut- ral format file to exchange the data between different CAD systems. Exchange of 3D CAD model data implies that the companies must exchange complete information about their products, all the way from design, manufacturing to inspection and shipping. This informa- tion should be available to each relevant partner over the entire life cycle of the product. This led to the development of an international standard organization （ISO） neutral format file named as standard for the exchange of product model data （STEP）. It has been ob- served from the literature, the feature recognition systems developed were identified as planar, cylindrical, conical and to some extent spherical and toroidal surfaces. The advanced surface features such as B-spline and its subtypes are not identified. Therefore, in this work, a STEP-based feature recognition system is developed to recognize t--spline surface features and its sub-types from the 3D CAD model represented in AP203 neutral file format. The developed feature recognition system is implemented in Java programming language and the product model data represented in STEP AP203 format is interpreted through Java standard data access interface （JSDAI）. The developed system could recognize B-spline surface features such as B-Spline surface with knots, quasi uniform surface, uniform surface, rational surface and Bezier surface. The application of extracted B-spline surface features information is discussed with reference to the toolpath generation for STEP-NC （STEP AP238）.展开更多
文摘A brief discussion of the content and methodology of STEP is given, and STEP based strategies for CAD/CAPP information integration is pointed out. A STEP based feature technology in which a three layer feature definition is included is discussed, the content of feature information is analyzed and a stratified CAD feature library is shown. On these bases, a commonly shared part information model is proposed. The architecture of the integrated CAD/CAPP system is presented.
文摘The information integration of CAD/CAPP is one of the crucial techniques in CIM. Thispaper desicribes an integrated CAD/CAPP system which is implemented by connecting MPIM to BR-CAPP via an interface for data exchange between them. The data exchange between MPIM and BR-CAPP is accomplished through STEP neutral file.
文摘The geometrical and topological information of 3D computer aided design （CAD） models should be represented as a neut- ral format file to exchange the data between different CAD systems. Exchange of 3D CAD model data implies that the companies must exchange complete information about their products, all the way from design, manufacturing to inspection and shipping. This informa- tion should be available to each relevant partner over the entire life cycle of the product. This led to the development of an international standard organization （ISO） neutral format file named as standard for the exchange of product model data （STEP）. It has been ob- served from the literature, the feature recognition systems developed were identified as planar, cylindrical, conical and to some extent spherical and toroidal surfaces. The advanced surface features such as B-spline and its subtypes are not identified. Therefore, in this work, a STEP-based feature recognition system is developed to recognize t--spline surface features and its sub-types from the 3D CAD model represented in AP203 neutral file format. The developed feature recognition system is implemented in Java programming language and the product model data represented in STEP AP203 format is interpreted through Java standard data access interface （JSDAI）. The developed system could recognize B-spline surface features such as B-Spline surface with knots, quasi uniform surface, uniform surface, rational surface and Bezier surface. The application of extracted B-spline surface features information is discussed with reference to the toolpath generation for STEP-NC （STEP AP238）.
