CAD模型隐式设计需求自动迁移

As an important part of case-based product design, case-based CAD model design, including CAD model retrieval and modification, can make impressive and innovative models for product design effectively. However, the effect of case-based CAD model design is still far from being satisfactory, which is mainly caused by the fact that a retrieved CAD model usually needs modifications by a designer for making it meet new design requirements, which is often time-consuming but ineffective. Building a source CAD model embedded with the primary new design requirements as one retrieval condition, designers always hope to obtain a target CAD model possessing the characteristics that are close to the new design requirements as much as possible in order to reduce the subsequent modification time.. Focusing on how to smartly adapt a target CAD model to meet the new design requirements implied by its source CAD model, the project aims to study the automatic adaptation for the mainstream CAD models, i.e. feature-based parametric models and assembly models, such that the redundant works can be reduced dramatically while the designers’ efficiencies are promoted significantly. The basic idea of the project is to realize automatic transferring implicit design requirements from a source CAD model to its target CAD model accurately according to their corresponding geometric elements, which can make the achievements independent of domain knowledge and suitable to be used widely. Finally, the project can not only improve the efficiency and quality for CAD model adaptation considerably, but also make the case-based CAD model and product design more intelligent.

基于实例的CAD模型设计，包含CAD模型的检索和修改，可以有效实现产品的快速创新建模，是产品基于实例设计中非常重要的环节。然而，该环节的实施效果尚不理想，其中一个重要的原因是检索获得的CAD模型通常依赖设计人员费时低效的交互修改才能符合新设计需求。为了提高修改效率，设计人员在检索时，往往会在检索条件里加入隐含当前主要设计需求的参考模型，以期借此检索到尽量接近新设计需求的CAD模型。据此，项目以设计阶段主流的CAD模型（参数化特征模型和装配模型）为隐式设计需求自动迁移的研究对象。研究解决如何将参考模型中隐含的设计需求自动修改到检索获得的CAD模型上的问题，以此减少冗余工作，提升设计人员的效率。通过确定CAD模型之间的几何对应关系来准确传递隐含的设计需求为研究思路，使得成果领域知识无关、适用范围广。项目的开展可以显著提高CAD模型修改的效率和质量，促进CAD模型及产品基于实例设计的智能化水平。

随着产品数字化设计的不断发展，CAD模型逐渐成为产品数字化设计的关键内容。研究表明，适应性重用现有产品实例的CAD模型，能够提升新产品的设计质量并缩短设计周期。然而，由于检索获得的CAD模型仍难以根据新的设计需求自动修改，导致目前CAD模型的适应性重用效率很不理想，继而影响了上述基于实例的产品设计方法在实际应用中的效果。针对上述情况，项目以实现CAD模型隐式设计需求自动迁移为目标，研究如何使得CAD模型能够通过几何对应关系将参考模型中隐含的设计需求自动准确地修改到检索获得的目标模型中，借此提升CAD模型适应性重用的效率。主要研究内容如下：. 1.参数化特征模型隐式设计需求自动迁移. 首先，基于关键面提取和面布局表征，提出一种关联模型面的模型整体形状描述符。其次，基于该描述符，提出一种组合优化方法来确定模型之间细粒度的几何对应关系。之后，提出一种双层次面语义布局来量化表征模型的隐式设计需求。最后，基于上述几何对应关系和面语义布局，融合对应尺寸约束传值和直接建模技术，实现目标模型按照参考模型的隐式设计需求自动修改——即使它们在几何细节和参数化方式上均存在巨大的差异。上述方法能够实现参数化特征模型自动高效地修改。. 2.装配模型隐式设计需求自动迁移. 首先，基于复杂产品需要分阶段装配成型的一般性规律，提出一种多层次属性布局图来由粗到细地表征装配模型的隐式设计需求。其次，通过层次图匹配，确定模型之间多层次的、易于适应性修改的语义和几何对应关系。最后，基于上述对应关系采，采用参数化特征模型隐式设计需求自动迁移和装配接口适应性移植，开展多层次的几何设计需求传递，实现目标模型按照参考模型的隐式设计需求自动修改——即使它们在几何形状上存在巨大的差异。上述方法能从语义和几何两个层面对装配模型实施自动高效地修改。. 项目成果可对产品的智能化设计、三维模型检索、装配工艺规划等领域的深入研究和工程应用提供有力的技术支撑。

内容获取失败，请点击重试