中文摘要：

在新产品开发进程期间，再使用模型能避免从头设计并且减少的存在 CAD 人的费用。与大数据的来临，怎么很快并且高效地为设计复用发现合适的 3D CAD 模型被花更多注意。当前，基于大意的检索途径使搜索更方便，但是它的精确性不足够高；在另一方面，语义底的检索途径充分利用高级语义信息，并且使搜索成为离工程师目的更靠近的大部分。然而，有效地提取并且表示从数据集合的语义信息是困难的。瞄准这些问题，我们为再使用 3D CAD 模型建议了一条基于大意的语义检索途径。第一好颗粒度语义描述符为代表 3D CAD 模型被设计；第二，几条启发式的规则被采用从在 3D 之间的 2D 大意，和通讯认出 3D 特征特征和 2D 环被造；最后，语义并且形状类似大小一起被联合匹配输入大意到 3D CAD 模型。因此检索精确性被改进。一个基于大意的原型系统被开发。试验性的结果验证我们的建议途径的可行性和有效性。

英文摘要：

During the new product development process, reusing the existing CAD models could avoid designing from scratch and decrease human cost. With the advent of big data,how to rapidly and efficiently find out suitable 3D CAD models for design reuse is taken more attention. Currently the sketch-based retrieval approach makes search more convenient, but its accuracy is not high enough; on the other hand, the semantic-based retrieval approach fully utilizes high level semantic information, and makes search much closer to engineers＇ intent.However, effectively extracting and representing semantic information from data sets is difficult.Aiming at these problems, we proposed a sketch-based semantic retrieval approach for reusing3 D CAD models. Firstly a fine granularity semantic descriptor is designed for representing 3D CAD models; Secondly, several heuristic rules are adopted to recognize 3D features from 2D sketch, and the correspondences between 3D feature and 2D loops are built; Finally, semantic and shape similarity measurements are combined together to match the input sketch to 3D CAD models. Hence the retrieval accuracy is improved. A sketch-based prototype system is developed.Experimental results validate the feasibility and effectiveness of our proposed approach.