【作者】 王远志；

【导师】 孙立镌；

【作者基本信息】 哈尔滨理工大学 ， 计算机应用技术， 2005， 硕士

【摘要】 语义特征造型系统采用完全语义约束定义特征和构建模型,能够全面地满足工程设计人员的各种意图,但是它较之以前的基于参数,基于历程的特征造型要复杂得多。它在底层采用特征依赖图保存数据模型,中层用细胞元模型作几何模型,在用户层用视图模型表示。模型设计是不断修改的过程,有修改就会有模型的重构,因此语义特征造型系统的重构是系统的重要部分。在重构过程当中,语义特征造型既要保证产品模型的可编辑性和易编辑性,又要保证编辑后的模型重构的高效性和语义一致性。模型重构中最关键的问题就是如何保持特征语义一致性,如何维护设计者的设计意图,如何保证产品信息的稳定性和完整性,以及如何提高模型的重构效率,并最终做到与历程顺序无关等。本课题将从理论和系统设计开发两个方面对模型重构中的关键技术进行深入的研究,把细胞元几何模型和特征依赖图数据模型结合起来统一进行分析,提出语义特征造型在模型重构过程中的新方法和新思想并给出相关算法。内容主要包括:基于完全约束的特征语义的分析,特征依赖关系图的更新与分析,细胞元几何模型的重构,重构顺序的分析研究,以及与历程顺序无关的约束求解算法。它使该系统趋向完整,更加稳定和实用。本文的研究成果可在HUSTCAID系统中得到实现,从而加速高质量产品的设计速度并为企业创造有形可观的经济效益,而且将在计算机图形学和CAD 这一领域对国内乃至国际将产生一定的影响,促进CAD 技术的更进一步发展。更多还原

【Abstract】 To the engineering designer, semantic feature modeling system, which adopts completely semantic constrains to define feature and create model, can satisfy all of their intents. It uses FDG as data model, cell-based model as geometric model, and view model as user interface, but it is more complex than the former system based on parameter and history. Designing model means modifying, and modifying causes re-evaluation, so its re-evaluation is an important part for the system. In the course of re-evaluation, not only must it be edited easily but also it can maintain its high efficiency and semantic conformity. The key problems are how to maintain its semantic conformity, how to protect designer’s intents, how to assure the stability and integrality of product information, and how to improve its efficiency. This paper will research the key issues for the model re-evaluation from the two aspects , theory and system design. We will combine the cell-based geometric model and FDG-based data model to analyze them, and bring forward the new methods and new thought for the model’s re-evaluation, with the associated algorithm. Its content includes the followings: the updating and analysis for the FDG, the analysis mechanism of constrain-based feature semantic, the research of cell-based geometric model, and the research of updating sequence, the re-evaluation research for the cooperative design through network, and so on. And based on the original data structure and algorithm of HUSTCAID. The research result can be applied in HUSTCAID, and have accelerate the speed of design and can contribute to the enterprise’s profits; furthermore, it can have some effect on the Graphic & CAD field in demotic even international area, and promote the CAD technology to advance more.更多还原