论文标题:面向图样理解的工程语义模型研究与应用
The Research & Application of Engineering Semantics Model for Engineering Drawing Interpretation
论文作者 钟军
论文导师 陆国栋,论文学位 硕士,论文专业 机械设计与理论
论文单位 浙江大学,点击次数 87,论文页数 84页File Size6748k
2002-02-01论文网 http://www.lw23.com/lunwen_863244577/ 集成网络模型;图样理解;工程语义;特征识别;工程图样;形体合成
integrated network model,engineering drawing interpretation,engineering semantics,feature recognition,engineering drawing,object composing
工程图样智能理解是一个典型的计算机图形学和计算机辅助设计学等学科的交叉课题。本文从面向工程图样理解的角度，通过工程语义的类别化、层次化和网络化处理，建立了形式化的工程语义集成网络模型，通过工程语义模型的综合应用，挖掘工程图样蕴涵的深层次信息，从而重建工程图样表达的三维形体信息。 首先，综述工程图样理解的相关内容、特征识别和形体合成等相关研究的进展，阐述本文的研究思路和工作。 其次，在分析工程图样的基础上，建立了工程语义集成网络模型。该模型从类别化的角度分为投影关系语义、尺寸约束语义和表达方式语义，从层次化的角度分为底层语义、中间层次语义和高层语义，从网络化的角度得到各个类别、各个层次之间的语义。对图样的工程语义进行表达和描述。 接着，根据工程语义模型表述，详细分析了各个类别、层次以及类别之间表达的工程语义的特点与内容，然后进行零件的特征分类，从特征识别的角度探讨了工程语义在图样理解的应用，并详细讨论了圆柱体、线性拉伸体、圆柱体的平面截切特征从投影语义、连通域语义、游离图元语义引导识别的应用过程。 最后，实现了工程语义模型，应用于图样理解得到三维形体。给出了系统实现框架并举了若干实例。
Engineering drawing intelligent interpretation is an intersectant subject of Computer Graphics and Computer Aided Design. For engineering drawing this dissertation formalizes the engineering semantics by divide and classify it, and establish a model of integrated network of engineering semantics. The model is applied to understanding 2D engineering drawing, extracting the deep information, obtaining 3D object.First, the research and relative subject on engineering drawing interpretation and feature recognition and object composing is summarized. The way of work is put forward.Second, the practical engineering drawing is analyzed and the model of integrated network of engineering semantics is established. According to the model, in respect of the content of engineering drawing the semantics is divided into the projection relation semantics, the expression mode semantics and the dimension constraint semantics. In respect of the deepness of information, the semantics is classified into the lower semantics, the middle semantics and the upper semantics. Furthermore the relation of the semantics is extracted. According to the model, all the engineering semantics is analyzed. These semantics lays a strong base for the 3D reconstruction and the engineering drawing understanding.Then, the features that describe 3D-entity are classified. The semantics is applied to engineering drawing interpretation by feature recognition. The application of semantics is discussed as follows: the projection relation semantics leading to recognizing cylinder, the region semantics leading to recognizing linear sweeping, the free element semantics leading to recognizing the feature which the cylinder is cut by plane.Last, a prototype system is developed according to the semantics model. The system can read dxf that contains 2D engineering drawing information and recognize the 3D feature.
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