基于逆向设计的产品造型注塑件创新设计

发布时间：2018-05-24 10:31

本文选题：点云数据 + 造型件特征线　；参考：《长安大学》2014年硕士论文

【摘要】：对现有产品或样机外观造型件进行仿制或改良，通常应用逆向工程方式进行。采用三维测量设备对造型件外表面进行测量，获取三维片点云数据，对片点云数据应用专用软件进行拼接、修整等处理，得到造型件的点云数字模型，应用数模进行造型件仿真与创新是逆向设计的主要过程。文中根据造型件数模创建过程，对影响造型件数模精度的因素及其控制方法进行了研究。首先应用三扫描仪VIVID910对产品造型件（文中取某电动车前脸）进行外表面片点云数据采集，应用InnovMetric Software逆向设计软件对片点云数据拼接、去噪、修补、多视对齐、精简、光顺与分割，获得低精度的造型件数字模型。对该数模按造型件几何形态特征与数模精度要求，应用InnovMetric Software软件构建一组特征平面（其数量与建模精度有关），提取特征平面与造型件数模的截面线，即为造型件的几何特征线。同样根据特征线特点与建模精度要求，在每条特征线上取一组特征点，将其作为特征线的型值点。根据造型件区域分割，同一区域的特征线取相同数量的特征点，分别用B样条曲线拟合各区域特征线，探讨造型件特征线按区域的统一参数化表示方法。集成MATLAB2010b软件、Microsoft SQLServer2005数据库技术，研究产品造型件特征线信息库系统开发方法与技术，使产品造型件众多特征线的信息、几何曲面信息实现自动化管理。以造型件外表面几何特征线上的特征点为型值点，应用积累弦长参数化方法、最小二乘法计算满足精度要求的控制点，构造B样条曲线，，用该B样条曲线代替特征线。造型件几何曲面拟合可看作两阶段B样条曲线拟合，即先对横向的每一特征线进行B样条曲线拟合，以此为基础，再在纵向进行B样条曲线拟合，即可构造出造型件外表面的近似网格曲面。在Pro/E中应用曲率分析等对重构曲面进行误差分析，探讨了建立了给定精度的造型件曲面重构方法与技术。应用软件UG自动生成实体图案，装饰电动车前脸（Matlab数模）生成新的前脸造型方案，将Matlab数模以Pro/E软件为桥梁保存为STEP格式。数模与实体图案以软件犀牛插入打开，通过UV展开功能实现实体图案与电动车前脸的结合。应用造型件创新方案数模直接进行注塑模具设计。在Pro/E软件中通过布尔运算实现型腔和型芯数模构建，并用Pro/E NC模块、后置处理模块编制能被数控机床控制系统识别的数控加工程序。
[Abstract]:The existing products or prototypes are modeled or modified, usually by reverse engineering. The 3D measuring equipment is used to measure the outer surface of the molded part, and the point cloud data is obtained, and the point cloud digital model of the molded part is obtained by using the special software for splicing, trimming, and so on. It is the main process of reverse design to use digital model to simulate and innovate modeling parts. In this paper, the factors that affect the precision of digital models of moulding parts and their control methods are studied according to the process of creating digital models of moulding parts. In this paper, the outside surface spot cloud data is collected by using the three-scanner VIVID910, and the point cloud data is spliced, de-noised, repaired, multi-view aligned and simplified by InnovMetric Software reverse design software. Smoothing and segmenting to obtain the digital model of low precision molded parts. According to the requirements of geometric shape feature and digital model precision, the digital model is used to construct a set of feature plane (its quantity is related to the modeling precision) by using InnovMetric Software software. The section line of feature plane and digital model of modeling part is extracted, that is, the geometric feature line of modeling part. According to the characteristics of feature line and the requirement of modeling precision, a set of feature points are taken on each feature line, which is regarded as the value point of feature line. According to the regional segmentation of modeling parts, the feature lines of the same area take the same number of feature points, and the B-spline curves are used to fit the feature lines of each region respectively, and the unified parameterized representation method of the feature lines of the modeling parts according to the region is discussed. Integrating MATLAB2010b software with Microsoft SQLServer2005 database technology, this paper studies the development method and technology of product modeling part feature line information base system, so that the information of many feature lines and geometric surface information of product modeling parts can be automatically managed. Taking the characteristic points on the geometric feature line of the exterior surface of the molded part as the type value, the accumulated chord length parameterization method and the least square method are used to calculate the control points which meet the precision requirements. The B-spline curve is constructed, and the B-spline curve is used to replace the characteristic line. Geometric surface fitting of modeling parts can be regarded as two-stage B-spline curve fitting, that is, B-spline curve fitting for each transverse characteristic line is carried out first, and then B-spline curve fitting is carried out in longitudinal direction on the basis of B-spline curve fitting. The approximate mesh surface of the outer surface of the molded part can be constructed. In Pro/E, curvature analysis is used to analyze the error of reconstructed surface, and the method and technology of surface reconstruction with given precision are discussed. The software UG is used to automatically generate entity pattern and decorate the front face of electric vehicle (Matlab digital model) to generate a new front face modeling scheme. The Matlab digital model is saved to STEP format with Pro/E software as the bridge. Digital analog and solid patterns are inserted into the software rhinoceros, and the combination of the solid patterns and the front faces of electric vehicles is realized by UV expansion function. The design of injection mould is carried out directly by using the innovative scheme of moulding parts. The mold cavity and core digital model are constructed by Boolean operation in Pro/E software. The NC machining program which can be recognized by NC machine tool control system is programmed by Pro/E NC module and post processing module.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB472

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