导　　师： 程耀东;柯映林

学科专业： H0201

授予学位： 博士

作　　者： ;

机构地区： 浙江大学

摘　　要： 在复杂外形产品re建模关键技术研究中,根据复杂外形产品re建模特点,提出了解决复杂产品re建模问题的反求工程cad综合建模方法.尽管基于nurbs曲面建模原理的通用cad/cam系统技术成熟、功能强大,但不太适合re建模的需要;基于tbs建模理论的专用re建模软件re-soft目前又难以满足产品开发要求.为此,提出了结合两种系统建模优势的反求工程cad综合建模方法,以加快cad建模进度.根据反求工程cad综合建模方法的需要,研究并解决了数据测量及数据预处理过程中一系列问题.这些问题包括:根据产品表面形状及建模方法,提出了一些选择测量方法的原则;研究了消除测量数据噪声信号、cmm测头半径补偿、测量数据边界处理、测量数据块拼合、数据补缺与补测等测量数据预处理问题.为了解决复杂外形产品re建模经常遇到的零件cad模型配合问题与尺寸精度、形状精度问题,作者研究了基于cad模型的修正、基于零件图样的修正、基于物理模型的修正等三种模型修正技术.使用这些cad模型修正技术,可以保证以re技术建立的零件cad模型完全满足装配要求,并且保证零件cad模型符合零件图样与(或)物理模型的尺寸和形状精度要求.在基于tbs建模的re系统与rp系统集成技术研究方面,通过分析现有re/rp系统集成方法特点,作者提出了从tbs曲面模型到stl文件的re/rp系统集成方法,且在原型系统上得到实现.在复杂外形产品快速开发系统框架研究方面,以re/rp系统集成技术为基础,结合internet/intranet网络技术,作者提出了以rpdtc为核心的产品快速开发系统框架,并在多项产品开发实例中贯彻了这一框架思想,取得了良好效果. All the Chinese enterprises will be thrown into the strongly global competition environment after China become a WTO member. How to enhance their ability about new product innovation as fast as possible is a magic weapon for they to win the global competition. So that, three topics in rapid development technology for complex shape product are studied in this paper: key technology for complex shape product reverse engineering/(RE/) modeling, integrating technology between RE system based on triangular Bezier surface /(TBS/) modeling and RP system, and investigation of rapid development system frame for complex shape product. In the study on key technology for complex shape product RE modeling, according to the characteristics of complex shape product, the reverse engineering CAD hybrid-modeling technology is proposed to build the product model with complex shape. On the one hand, although the commercial CAD//CAM system that based on NURBS surface theory is reliable and possesses strong functions, it isn't very suitable for RE CAD modeling. On the other hand, the RE-SOFT software, a special software for RE modeling based on TBS theory is difficult to meet the product developing. Therefore, the reverse engineering CAD hybrid-modeling technology has to combine two kind of system to reach the goal of reducing CAD modeling process. According to the requirement of the reverse engineering CAD hybrid-modeling technology, a series of problems such as data capture and data preprocessing are investigated and solved. The research results include the follows: present some rules for selecting measuring method according to the characteristics of product, study some problems in data preprocessing such as noise removing, probe radius compensation, edge data extracting, sun-regions merging, and local data mending or re-sampling etc. To ensure the part CAD models being built and assembled accurately at dimension and shape in RE modeling application, three kinds of model modifying techniques are presented such as model-based modifying, drawing-based modifying and physical model-based modifying. Using these modifying methods, the RE CAD model of parts can meet the assembly and accord with the part drawings or /(and/) physical model in both of dimension and shape. To design the local features in product digital modeling, some surface local features are assorted and defined. Furthermore, several methods for surface local features design are proposed such as the treatment of CAD model edge features, design of the near-edge surface features, and design of the inner-surface feature. On the integrating technology between RE system based on TBS modeling and rapid prototyping /(RP/) system, the differences of some current integrating technology are researched, and the RE//RP systems integration technology by converting the TBS surface model into STL files is studied, and this technology is realized at a prototype system. In this technology, a theory which can be used to divide the TBS's base surface patch into triangle patches or unite several TBS's base surface patches into one triangle is presented, and some problems concerned with dividing the base surface patch into triangle patches are studied and solved such as cracks between triangle patches, computing the number of segmenting of the edge at base surface patch, computing the dividing number of the base surface patch, generating the triangle patches etc. How to combine several TBS's base surface patches into one triangle is also studied and solved. The prototype system realized all the above technologies, and the TBS can be converted into STL model by uniform dividing or optimized dividing methods, and two kinds of STL files, i.e. binary file and ASCII file can output. In this way, the RE//RP systems integration based on TBS model is successfully realized. Finally, a frame of RDSFCSP /(rapid development system for complex shape product/) is presented based on the integration of RE//RP systems. A remote product developing technology center /(RPDTC/) is the most important partner in this

关 键 词： 反求工程 快速成型 曲面局部特征 系统集成 产品数字模型

分 类 号： [TH164]

领　　域： [机械工程]