【作者】 崔焕勇；

【导师】 李兆前；

【作者基本信息】 山东大学 ， 机械制造及其自动化， 2006， 博士

【摘要】 作为支持产品快速开发和产品创新的有力工具，反求工程技术得到了越来越多的关注和应用。本文以复杂形状实体反求工程为研究对象，研究反求工程中影响反求产品精度和反求效率的关键技术问题，并构建高效的协同集成反求工程系统。 针对实体反求工程的特点，利用测量数据点构建三次插值样条，依据光顺原则判断噪声点，并对已知的噪声点进一步判断，提取出有用噪声点，作为后续数据处理的型值点，同时去除无用噪声点，保证重构曲线或曲面的光顺性，避免重构曲线或曲面局部失真，以真实地反映原实际曲面的形貌。 采用测头中心点所在曲面法矢估算的空间补偿方法，将转动惯量引入到测头中心点所构成的曲面上各点处法矢的求解方法中，提出并实现了测头半径自动补偿的“转动惯量法”，并验证了该方法的有效性，结果表明，该方法比常用的“平均矢量法”的计算精度有明显提高，更适合于复杂形状曲面测量中的测头半径补偿。 综合目前离散数据分块特点和曲面重构技术应用特点，提出了基于非几何特征的离散数据分块思想，通过对基于扫描线排列的离散数据点的三角Delaunay直接剖分，利用局部三角形域的中心三角形与贴邻三角形间的法矢变化进行“光顺带”提取，并在光顺带中间部位实现离散数据的分块，该方法有利于提高后续重构面片的保形性和面片间拼接的连续性。 针对复杂形状实体反求中，难以实现基于海量数据进行NURBS重构的问题，提出了基于非特征数据分块的曲面重构方法，给出了基于非特征分块数据的曲面重构技术路线，提出了基于分块数据重构的“虚拟测量”方法，采用NURBS方法整体重构最终曲面，其表达格式符合IGES和STEP数据转换标准，可以很容易地读入CAx系统。通过对汽车缩微模型车身部分的反求过程，更多还原

【Abstract】 Reverse Engineering(RE) is becoming an effective and efficient tool in supporting the rapid development and innovative design of product. In order to extend the application of RE technology, some key issues influencing the precision and efficiency of product in RE for complex objects were researched in this paper. And a high efficient Collaborative Integrated RE System(CIRES) was studied and developed.Noisy points need to be distinguished and extracted from the large scale of "point clouds", which are inevitable in the process of surface data acquisition in RE. By evaluating the smoothness of the cubic interpolation B-spline curve which is built up based on the data points in every measurement plane, noisy points can be distinguished. Some noisy points which are useful in improving the smoothness of spline after their being manipulated are called "useful noisy points" and regarded as data points for subsequent processes. The others called real noisy points are eliminated from the point clouds. By using this new method to manipulate the noisy points, reconstructed surfaces are more like the actual ones without local distortion.The critical question in solving the probe radius compensation is the precise calculation of the center-point’s normal vector of the surface decided by the probe track. A concept of moment of inertia is introduced and the relative method is put forward, which can be used in the automatic compensation of probe radius. It is proved that the result obtained with the moment of inertia method is more accurate than that of the universal "average vectors method" in complex surface RE.Considering synthetically the characteristics of both segmentation technology更多还原