【作者】 刘婧瑶；

【导师】 李建华；

【作者基本信息】 西安科技大学 ， 机械制造及其自动化， 2006， 硕士

【摘要】 随着全球化竞争的日益激烈和买方市场的迅速形成，制造业的快速产品创新设计能力已成为决定企业兴衰成败的首要因素。逆向工程技术作为实现快速创新设计的重要途径，已经受到越来越多的关注。 基于约束的结构类零件特征模型重建是逆向工程中一个新的研究方向，具有很强的理论意义和实用价值。当前主流的3D CAD软件如CATIA、Pro/Engineer等在实体建模时主要是基于草图设计的。本文在特征数据分割的基础上，结合正向设计的思路，着重研究结构件中的拉伸、旋转等基于草图的特征模型重建问题。本文研究的主要内容如下： 1) 根据平面轮廓数据点处的近似曲率变化识别出特征点，并确定特征点类型； 2) 利用“非均匀原点距离法”对二维数据点精减； 3) 采用“正负偏差累加法”判断各段数据点确定的曲线类型，基于约束对分段的平面轮廓曲线进行整体拟合； 4) 研究并推导无约束直线段和圆弧段的拟合方法及有约束圆弧段的拟合方法； 5) 结合Pro/ENGINEERING的逆向工程专用模块，实现了旋转实体、拉伸实体及从文件混合高级曲面模型的生成。更多还原

【Abstract】 With the forming of the buyers’ market, the trend of global competition has been intensified much more than before. The ability of developing new product rapidly for manufacturing enterprise already becomes the chief factor, which determines the enterprise’s fortune. As an important approach of rapid creative design, Reverse Engineering has got more attention.The research on constraints based structural feature model reconstruction method is a new aspect in reversing engineering, which can be used to reconstruct more reliable model. Modeling in current 3D CAD software such as CATIA、pro/Engineer are mainly based on sketch design. According to the idea of modeling and on the basis of segmenting 3D data with feature design intention, this thesis studies the reconstruction methods of model sketch-based feature such as extruded and rotational features in structural part models. The main contents of this thesis are as follows:1) According to the approximate curvature of each contour point, the feature points are recognized from the point-data; the styles of them are confirmed.2) The unsymmetrical origin-distance approach is adopted to reduce the 2D point-data.3) After confirming the segments types (line or circle) we call that approach as "Sign Error Accumulative Total". The contour is globally constructed through determining the constraints with the neighbor segments.4) Studying and deducing the reconstruction methods of unconstraint beeline segments, unconstraint circle segments, and constraint circle segments.Applying the reverse engineering tools of Pro/ENGINEERING to realize model generation of the rotational entity, extruded entity, and advanced surface of Blend from File.更多还原