Research And Implementation Of A Flexible Two-dimensional CAD System

The application of CAD technology has penetrated in almost every field of designing and manufacturing. After decades of development, appeared a group of outstanding commercial software, such as AutoCAD, UG, CAXA, there are also some open source CAD software, such as FreeCAD and QCAD. Commercialized CAD software, though powerful, but it is expensive, and the enclosed design limits the integration with other software. Open source CAD software generally has poor security, not easy to use, and it is difficult to transplant. Therefore, the application of CAD technology is not widespread used in small and medium-sized CNC enterprises. Thus, it is very necessary to develop CAD system which has strong practicability, good scalability, and suitable for small and medium-sized CNC enterprises.Based on the above reasons, this paper puts forward a kind of open flexible two-dimensional CAD software architecture which is based on "global management engine + independent module". The architecture based on the idea of pure modular, high cohesion and low coupling between modules, making the software easy to extend. Based on the above architecture, designed the module management engine, the engine's function is dynamic loading, automatic configuring and rapid upgrading of the various modules of 2D CAD system. Two dimensional CAD system mainly includes the basic data structure module, algorithm module, input module, output module, data management module and an editing module. For each module, this paper gives the specific design ideas.One main function of numerical control software is to read the external files, such as DXF, IGES and Gerber. This paper solved the problem of fast parsing of the DXF file, the parsing speed is closed to the Auto CAD2008. Parsing SHX font file which is mainly used to marking.Based on the proposed flexible two-dimensional CAD architecture, developed customized two dimensional CAD module for several CNC software. This several customized two-dimensional CAD modules has been successfully applied in cutting and welding rapid prototyping software which is developed by Orion laboratory of Huazhong University of Science and Technology. The flexible architecture makes development more efficient, the entire development process can be parallel to, some of the results can be directly applied to the development of new software,thus avoid the iterative development.