The Study Of Web-Based NC Programming System And Its Key Technologies

With the rapid popularization of Internet and the development of Web technique, profound innovations are turning up in the area of the traditional product design, manufacturing and production mode. Consequently, a series of new concepts and new techniques concerning collaborative design and manufacturing, geographical distributed design and manufacturing and global manufacturing are coming out. NC machining can not only guarantee the production with extremely high accuracy and stable quality, but also operate automatically, achieve high productivity and shorten the pre-production period. It can satisfy the need of rapid product updating. NC programming is the basis of NC machining, whose quality and efficiency are the keys to enhancement of the level of NC machimng.The integration of Web and CAD/CAM technique, is the trend of CAD/CAM system. In the dissertation, the Web based NC programming system which combine Web technique with NC technique is studied, and it is of great significance in theory and practice.The dissertation points out that Web based Browser/Server computing model will be the trend of applied software on the ground of the analysis and comparison of computing models of Terminal/Host, Client/Server and Browser/Server. Meanwhile, the Web technique and Web-based software development technique are also discussed. IDEFO function model of WebCAM system is built on the foundation of the requirement analysis of Web based NC programming system.The dissertation put emphasis on the key technique of implementation of Web based NC programming system. It includes: I) The implement technique of WebCAM with Java, is studied. The 3 tier Browser/Server architecture model is proposed. The Java Applet technology on client side, Java Servlet technology on server side, the JDBC communication technology between Server and Database, and the software launching technology are discussed. 2) A new algorithm by judging loop direction according to loop area is proposed. 3) An algorithm to determine the best direction of zigzag machining using the least repeating time of the range of pits is proposed. The algorithms of loop offset, loop self-cross and mutual-cross, the tool path generation and remaining material machining are implemented. 4) The algorithm of spiral machining tool path generation is implemented. 5) Based on the research of NC simulation method, a triangular grid model which is suitable for 2-3D visual NC simulation is proposed.According to the theoretical studies above, a prototype system of WebCAM has been established. The system can provide the following functions in Web browser: NC machining parameter selection, the tool path generation of 2.5D pocket machining, 2.5D profile machining, 3D rough machining, 3D parameter curve machining and 3D multisurface project machining, post-processor, NC simulation, etc. All those prove that the approaches proposed in the dissertation are feasible, and moreover, accumulate rich experiences for the future research.