By adopting the parameterized designing method of f ea ture assembled and feature unit, for the feature of non-conventional type parts , such as welding box and bearer, by use of Visual C++ and AutoCAD a s soft tools,...By adopting the parameterized designing method of f ea ture assembled and feature unit, for the feature of non-conventional type parts , such as welding box and bearer, by use of Visual C++ and AutoCAD a s soft tools, the system can successfully carry out the basic function of featur e assembled, the processing of two-dimensional figure, the building of three-d imensional feature, the automatic producing of technical papers, and so on. The thoughts and design methods of this system can be served as the preference to CA D/CAPP integrated for othernon-conventional type parts. For non-conventional parts, its feature is too much, so the parameter is much. By adopting interactive entry for graphic parameter, under the control of main c ontrol module, through inputting the feature parameter and calling the feature g raphic unit, the function for modeling is completed. To reduce input of feature parameter, the description of position feature is adopted in the feature descrip tion of non-conventional parts, that is, fix position is constraint through str ucture and dimension of non-conventional parts. In such a manner, the assembled process has been transformed the coordinate conversion process, and this is ver y important in the production of three-dimensional graphics. In the one hand, b y calling the feature of parts in the library of feature-graphic unit, the two -dimensional DXF file and three-dimensional SCR file are automatically produce d in AutoCAD. On the other hand, by calling the rules and standard operational s equences in the technologic knowledge base, through inferring of inference engin e, the assembled sequence of non-conventional parts and welding sequences are a utomatically produced. The two aspects constitute overall design philosophy for system. So the CAD/CAPP integration of feature-assembled for non-conventio nal parts are completed. The principle of dividing feature is based on the thought of group technology, t hat is, according to the function feature of parts. The feature-assembled p arameterized design method is to divide the parts into many feature-units, acco rding to the structure, function, and secondary feature, and the each unit is in teractively produced, so the whole part is assembled gradually. At the same time , to display the sequences which deviser chooses varied features, hidden feature code is adopted. The feature-unit parameterized design method is to assemble dimension, margin tolerance and fitting-in, and surface roughness into one unit that it becomes a fixed structure. However big it is, it could be added to or taken off like a ba sic feature-unit.By adopting above-mentioned methods, the module of parts is e stablished. Under the integrated environment, according to basic construct of expert system, CAPP system is made up of three sectionsdynamic database (document-view ), knowledge library and inference engine. Dynamic database is served as storing initialized and middle information as well as ultimate design result. The knowl edge library is composed of static database, rule set, and standard welding proc ess library.展开更多
文摘By adopting the parameterized designing method of f ea ture assembled and feature unit, for the feature of non-conventional type parts , such as welding box and bearer, by use of Visual C++ and AutoCAD a s soft tools, the system can successfully carry out the basic function of featur e assembled, the processing of two-dimensional figure, the building of three-d imensional feature, the automatic producing of technical papers, and so on. The thoughts and design methods of this system can be served as the preference to CA D/CAPP integrated for othernon-conventional type parts. For non-conventional parts, its feature is too much, so the parameter is much. By adopting interactive entry for graphic parameter, under the control of main c ontrol module, through inputting the feature parameter and calling the feature g raphic unit, the function for modeling is completed. To reduce input of feature parameter, the description of position feature is adopted in the feature descrip tion of non-conventional parts, that is, fix position is constraint through str ucture and dimension of non-conventional parts. In such a manner, the assembled process has been transformed the coordinate conversion process, and this is ver y important in the production of three-dimensional graphics. In the one hand, b y calling the feature of parts in the library of feature-graphic unit, the two -dimensional DXF file and three-dimensional SCR file are automatically produce d in AutoCAD. On the other hand, by calling the rules and standard operational s equences in the technologic knowledge base, through inferring of inference engin e, the assembled sequence of non-conventional parts and welding sequences are a utomatically produced. The two aspects constitute overall design philosophy for system. So the CAD/CAPP integration of feature-assembled for non-conventio nal parts are completed. The principle of dividing feature is based on the thought of group technology, t hat is, according to the function feature of parts. The feature-assembled p arameterized design method is to divide the parts into many feature-units, acco rding to the structure, function, and secondary feature, and the each unit is in teractively produced, so the whole part is assembled gradually. At the same time , to display the sequences which deviser chooses varied features, hidden feature code is adopted. The feature-unit parameterized design method is to assemble dimension, margin tolerance and fitting-in, and surface roughness into one unit that it becomes a fixed structure. However big it is, it could be added to or taken off like a ba sic feature-unit.By adopting above-mentioned methods, the module of parts is e stablished. Under the integrated environment, according to basic construct of expert system, CAPP system is made up of three sectionsdynamic database (document-view ), knowledge library and inference engine. Dynamic database is served as storing initialized and middle information as well as ultimate design result. The knowl edge library is composed of static database, rule set, and standard welding proc ess library.
