逆向工程中基于特征提取的建模技术研究

发布时间：2018-01-12 01:15

本文关键词：逆向工程中基于特征提取的建模技术研究　出处：《广东工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着科技和经济日益朝全球化方向发展,逆向工程技术作为一种消化吸收先进设计理念的设计方法,逐渐受到各国学术界和工业界的重视。实物逆向工程技术以重构产品实物的CAD模型为主要研究内容,而CAD模型是现代产品开发、制造生产、再设计和修复破损零部件等的基础。因此,基于产品实物的逆向工程技术不仅是航空航天和汽车等行业的一种重要的设计方法,而且在文物保护、破损零件修复及再制造等方面也有重要作用。基于产品实物的逆向工程技术的主要目的是重构得到准确、有效的CAD模型,即其核心是逆向建模技术。目前,根据重构CAD模型过程中提取特征和最终建模结果的不同,可将逆向建模技术分为两种：基于曲面重构的逆向建模方法、基于实体重构的逆向建模方法。基于曲面重构的逆向建模方法是相对发展得较早的一种逆向建模方法,该方法重构的CAD模型是曲面模型,在基于重构CAD模型的基础上进行再设计、CAE结构仿真分析等方面受到限制。而且该方法通过提取曲面特征来重构CAD模型,在重构机械零部件的几何形状时无法准确反映某些几何规则特征及其相互之间的约束关系。因此,本文针对基于曲面重构的逆向建模方法中的建模缺陷,对逆向建模方法中的研究热点——基于实体重构的逆向建模方法——进行了重点研究和介绍。该方法可从由原始测量数据预处理后得到的三角网格面模型中识别并提取实体特征,或识别并提取实体特征的相关元素后应用正向建模方法还原实体特征。另外,通过对提取的实体特征进行参数化编辑修改,可精确定义特征的几何参数及特征之间的约束关系。本文利用实体逆向建模方法中的特征识别与提取功能,提出了针对残缺数据的逆向建模方法,并以某一机械零部件的残缺三角网格面模型为例重构其实体模型,以对该方法的建模流程和特点进行了具体介绍和验证分析。本文另一部分工作是针对航空航天行业中复杂的机械零部件,无法应用单一的逆向建模方法重构得到准确、有效CAD模型的问题,提出了基于曲面和实体特征提取的混合逆向建模方法,在结合不同逆向建模软件平台以重构复杂工业产品CAD模型的应用上进行了有益尝试。
[Abstract]:With the development of science and technology and economy towards globalization, reverse engineering is a design method that absorbs advanced design ideas. Physical reverse engineering technology focuses on reconstructing the CAD model of products, while CAD model is modern product development, manufacturing and production. Therefore, reverse engineering based on products is not only an important design method in aerospace and automobile industries, but also in the protection of cultural relics. The main purpose of reverse engineering technology based on products is to reconstruct accurate and effective CAD model, that is, reverse modeling technology is the core of it. At present, the main purpose of reverse engineering technology is to obtain accurate and effective CAD model. According to the difference of feature extraction and final modeling result in the process of reconstructing CAD model, reverse modeling technology can be divided into two kinds: reverse modeling method based on surface reconstruction. The reverse modeling method based on surface reconstruction is a relatively early reverse modeling method, and the CAD model reconstructed by this method is a surface model. Based on the reconstructed CAD model, the simulation analysis of the redesigned CAD structure is limited, and the method reconstructs the CAD model by extracting the surface features. The geometric shape of mechanical parts can not accurately reflect some geometric characteristics and their mutual constraints. Therefore, this paper aims at modeling defects in the reverse modeling method based on surface reconstruction. In this paper, the research focus of the reverse modeling method, the reverse modeling method based on entity reconstruction, is mainly studied and introduced. The method can be identified from the triangular mesh model obtained from the preprocessing of the original measurement data. And extract the entity features. Or identify and extract the relevant elements of entity features and then use forward modeling method to restore entity features. In addition, the extracted entity features are modified by parameterized editing. The geometric parameters of features and the constraint relations between features can be precisely defined. In this paper, a reverse modeling method for incomplete data is proposed by using the feature recognition and extraction function in the method of entity reverse modeling. Taking the incomplete triangular mesh model of a mechanical part as an example, the entity model is reconstructed. The modeling process and characteristics of this method are introduced and verified. Another part of this paper is aimed at the complex mechanical parts in aerospace industry. A hybrid reverse modeling method based on surface and entity feature extraction is proposed, which can not be used to reconstruct the accurate and effective CAD model with a single reverse modeling method. A useful attempt has been made in reconstructing the CAD model of complex industrial products with different reverse modeling software platforms.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB47

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