Based On Web 3D CAPP Management System And The Research And Implementation Of Tolerance Information

Along with the development of the computer technology, computer aided design (CAD) and computer aided process planning (CAPP) are playing more and more magnificent roles in the enterprise informatization and modernization process, as well as, CAD and CAPP can assist enterprises to reduce the cost and time. However, nowadays, CAD and CAPP lack of humanization in many aspects, for instance, the two and three dimensional graph and process information of the same part or assembly are saved in the different location, which is inconvenient for designer to locate. Moreover, the inconvenience are represented in the two-dimensional graph, such as the steps of tolerance marking are various and complicated. In order to solve the problems above, this thesis combines the Web technology and CAPP, and studies the tolerance marking in CAD.The research works of the thesis are mainly represented as following contents:1. The thesis analyzed the history, current situation and future of the CAPP system, it also concluded the problems exist in the system. It studied the trend of the development of the system. Meanwhile, it came up with a three-dimensional process resource management system based on the Web, as well as, achieved sharing of 3-dimensional models and concentrated reflection of visualization through the Web page compiled. In addition, building Database for the system makes operations such as sharing and adding achieved through calling the Database by the process data of the resource managing through the interface.2. The thesis discovered some problems about current softwares which involve tolerance marking via analyzing the tolerance marking module in the mainstream 3-dimensional modeling softwares and their modified packs. The tolerance marking problems are as follows:the function is deconcentrated, the marking steps are complicated and the ambiguousness of the marks. After the research of these problems, the thesis came up with the interface creation based on the HTA theory. During the process, the HTA theory was introduced. In addition, the steps of solution with HTA were explained. At last, the interface was created guided by the theory.3. After the interface designing, the tolerance distribution of assembly was studied based in the 3-dimensional virtual environment. The thesis briefly concluded current mainstream algorithm of the tolerance distribution, furthermore, it came up with a novel algorithm for the tolerance distribution which improved the ones already exist, and evaluate the tolerance with the method six-s.