Research And Implementation Of CAD System Platform Based On Component Technology

The present CAD software faces the problems of a long term of development, lack of maintainability, deficiency of interface-based development. In order to change the state, this thesis puts forward a way by infusing object-oriented and component technology into the traditional CAD software development to construct a reusable CAD software platform, and implements the fast development of custom-built CAD software. This project got financial support from National High Tech Development Plan Fund (863 plan). This thesis carries through the research on the development of a reusable CAD software platform from three aspects, that is, how to construct an open architecture, a highly cohesive function module and an extendable data structure. The thesis puts forward a "Component-Bus" architecture, dividing the whole system into four layers: development environment-supporting layer, bottom service layer, platform management layer and system application layer. At the platform management layer, four control buses are designed to uniformly manage all the function modules. Thus, Multi-scheme of reuse development can be realized due to this kind of layer architecture. Various CAD functionalities are analyzed and sorted on engineering application domain level, and implements each module's zero-coupling. Each model is self-function-maintained. An open data model is built by analyzing the data structure of CAD system. The model successfully implements the uniform management of the system data by data-registration, solving data's openness problem.The principles stated above combine with component technology to thoroughly reconstruct the old KMCAD, implementing the data integration between KMCAD and KM series products such as BOM, CAPP and PDM. Some algorithms (mainly include intersection algorithm between free-curves and physical feature algorithm) of the calculation library are improved and expanded. Besides, the thesis carried out two ways of user interface-based development in KMCAD system: one is "the system-involved developing mode", the other "user model embedded model". KM-3D CAD and Haerbin piping intelligent CAD expert system for Haerbin air-conditioning Co., Ltd. are successfully developed based on KMCAD platform. The feasibility and valibility of platform are verified by its market spread and practical use, gaining good economic and social benefits.