【作者】 肖丽雯；

【导师】 秦鹏飞； 何援军；

【作者基本信息】 东华大学 ， 机械设计及理论， 2002， 博士

【摘要】 随着计算机技术的发展，全球化制造时代已经到来。在这种背景下，利用集成化、智能化CAD系统完成产品的开发设计是企业赢得市场竞争的重要保证。因此，对集成化、智能化CAD系统的研究，已经成为设计领域的发展趋势。 设计问题本质上是一个约束满足问题(Constraint Satisfaction Problem，CSP)，即给定功能、结构、材料及制造等方面的约束描述，求得满足设计要求的设计对象的细节。现行的CAD系统能较好地处理复杂的零件图，但在装配图的设计方面，却显得薄弱无力，缺乏完善、可靠的装配建模工具。然而，装配图是产品设计中极为重要的技术文件，它对提高设计效率，缩短设计周期都具有重要的意义。 本文以基于网络的零件库技术以及装配约束满足问题(Assembly Constraint Satisfaction Problem，ACSP)为主线，对集成化的智能CAD进行了研究，建立了基于PPLIB(Parametric Parts LIBrary)的装配图参数化设计系统。 本文首先系统全面地分析了国内外关于集成化的智能CAD系统的最新研究成果，采用面向对象的建模方法，构筑了基于PPLIB的装配图参数化设计系统的体系结构，并采用IDEFO结构分析方法建立了参数化设计系统的功能模型。 通过对约束满足问题的研究，建立了基于约束的产品几何模型，提出了对几何约束系统进行简化的方法，并给出了几何约束系统的图表达形式，阐明了几何约束网络图的基本性质。在此基础上，提出了一种面向零件图的基于点簇归约的几何推理算法，并且构筑了局部约束求解器。它能通过约束识别和几何推理自动建立起几何元素之间的依赖关系和求解次序，成功地实现了比较复杂的图形的参数化设计。 在深入研究PLIB标准的基础上，采用NIST Expresso和WinSTEP等工具构筑了基于PLIB的产品信息模型。通过局部约束求解器和草图规整器等工具建立基于约束的产品几何模型，为支持企业在Intranet网上开展协同设计、共享设计资源，根据零部件库的实际使用情况，选择并改进了PLIB标准建议的第二种集成方案，建立了基于PLIB的信息集成系统，实现了不同CAD间产品级的信息交换，创建了机械领域的基于Internet／Intranet的参数化零部件库PPLIB。 深入探讨了装配约束满足问题的求解机制，提出了基于块的全局约束求解算法，约束一致性算法和约束方程组求解算法，建立了几何约束求解系统、几何约束管理系统、约束方程组求解系统，在此基础上构筑了二维约束求解器，实现了东华大学博士学位论文摘要装配约束满足问题的求解。 最后，以河南平顶山平高电气股份制有限公司的GIS软件项目为实践背景，采用面向对象方法开发了装配图的参数化设计系统，通过推广应用，实践表明，本文提出的理论和方法是正确的。 综上所述，本文的研究在以下几个方面有所创新:1.建立了支持自顶向下和自底向上的装配图设计系统框架;2.通过对几何约束系统的简化，建立了基于约束的产品几何模型及其存储结构， 并提出了基于几何约束网络图的产品几何模型的求解模型。3.提出了基于点簇归约的几何推理算法，并在此基础上建立了局部约束求解器。 成功地实现了局部约束满足问题的求解。4.建立了基于PU[B标准的产品信息模型，提出了不同CAD系统间产品级信息 集成方案，实现了不同CAD系统间的零部件库的集成。5.提出了基于块的全局约束求解算法，在此基础上建立了二维约束求解器，实 现了装配约束满足问题的求解。更多还原

【Abstract】 With the development of computer technology, the global manufacture era is coming. Under this background, using integrated and intelligent CAD systems to accomplish product design is important ensure for the enterprises to win the market competition. Therefore the study on integrated and intelligent CAD systems has become the trend in design field.The design problem is essentially a constraint satisfaction problem. Given the functional, structural, material, manufacturing constraints and so on, find the details of design object in line with the design requirements. Current CAD systems are good at dealing with complicated part drawings, but are week in the design of assembly drawings. However, assembly drawing is an important technical file, which contributes to improve design efficiency and shorten design cycle.Our discussion is focused on parts library technology based on network and assembly constraint satisfaction problem (ACSP). In this paper we present a deep study on integrated ICAD and build a parametric design system of assembly drawing based on PPLD3 (Parametric Parts Library).Firstly, the background and related work in the field of integrated ICAD research are introduced. The architecture of parametric design system of assembly drawing based on PPLJB is set up using the object oriented modeling method. And the functional model of parametric design system is built using the IDEFO structural analysis approach.Then based on the deep study on PLIB standards, the product information model based on PLIB is set up using the tools such as NIST Expresso, WinSTEP and so on. To support the collaborative design and the share of design resource, the second integration project suggested by the PLIB standards is selected and modified and the information integration system based on PLIB is set up. The information exchange between different CAD systems is implemented.The geometric model of products is set up by studying on CSP. The simplified method for geometric constraint system is presented and a graph representation is used todescribe the geometric constraint system. The characteristics of the geometric constraint network is also given. A part drawing oriented geometric reasoning algorithm based on point-cluster reduction presented and a local constraint solver is set up. It can obtain the solving sequence of geometric elements from the geometric constraint network and achieve the parametric design of complicated drawings. The tool for building PPLB is set up using the local constraint solver and PLJB technology.The solving mechanism of ACSP is discussed and the global constraint solving algorithm based on block is proposed. The 2D constraint solver is built based on the local constraint solver and PPLBB to achieve the parametric design of assembly drawing.Finally, under the practical background of the project of GIS parametric design software, the development of the parametric design system of assembly drawing based on PPLJB is carried out. The future work in this area is addressed.In conclusion, there are some innovates listed below in this paper.1. The architecture of assembly drawing design system which supports bottom-up and top-down assembly design is set up;2. The parametric geometric model of product based on constraint is set up, and the solving model based on constraint network graph for the product geometric model is proposed;3. The parametric information model of product based on PUB is set up, the method of product information exchange between different CAD systems through PLJB is designed, and the integration of parts libraries between the different CAD systems is implemented;4. The geometric reasoning algorithm based on point-cluster reduction is put forward, and the local solver is set up based on it, the local constraint solving problem is solved;5. The global constraint solving algorithm based on block is proposed, and the 2D constraint solver is set up, the parametric design of assembly drawing is realized.更多还原