头盔的逆向造型与设计

车辆工程专业毕业论文，论文编号:JX938  论文字数:14311.页数:29

摘    要

 传统的正向设计为 CAD 软件中的虚拟设计，在绘制复杂曲面模型时，相当费时费力；在设计人性化产品时，更是需要反复实验、修改才能达到要求；等等。因此，正向设计在开发此类产品时存在高成本、低质量、长周期等不足。逆向工程技术能弥补正向设计的不足。运用逆向工程，可以将无论多复杂的已有产品或者物理模型迅速转化为与原形基本一致的三维CAD 模型，可对此模型进行改良或创新设计。新产品的设计不再仅仅是CAD 软件设计，可以是物理模型设计与 CAD 设计的实、虚结合。逆向工程技术还可与快速成形技术(RP)、快速模具技术(RT)集成，形成一个产品快速开发系统。
 本文根据头盔的点数据，按照逆向造型的一般过程：测点、连线、构面、曲面的品质分析、构体；综合运用UGNX4.0软件完成头盔的三维造型。在此基础上运用UGNX的建模模块完成模型的重构，得到合理的头盔曲面，以及根据合理的曲面完成三维模型的重构。文章从为什么选题，背景，意义等结果出发，通过分析各种软件的功能及结合自身情况选用UGNX4.0作为应用软件，解决了逆向造型中的数据处理，面构造，实体构建等问题。

关键词：头盔  点云  逆向工程  曲面造型

Abstract

 Traditional CAD software being designed for the virtual design, rendering complex surface models, it is time consuming; in the design of personalized products, but also requires repeated experiments, modified to meet the demand; and so on. Therefore, the positive design of such products exist in the development of high-cost, low quality, lack of long cycles. Reverse engineering technology designed to make up for being insufficient. The use of reverse engineering can be, no matter how complex or existing products quickly into the physical model is consistent with the prototype three-dimensional CAD model, this model can be improved or innovative design. New product design is no longer just CAD software design, which can be physical model design and CAD design real and imaginary combination. Reverse engineering with rapid prototyping technology can be (RP), rapid tooling (RT) integrated to form a Rapid Product Development System.
 According to the helmet of the data points，according to reverse the normal process modeling, The integrated use of software UGNX4.0 completed the three-dimensional modeling lights. On this basis the use of UGNX MoldWizard module completed die design，get a reasonable surface helmet and optimize the process parameters of the die structure. Why topics from the article, background, the significance of the results , by analyzing the various software functions and the situation in light of its own choice as the application software UGNX4.0，Solve the reverse form of data processing，Structure of Surface, Construction of entities such issues.

Key words: Helmet   Point cloud   Reverse engineering  Surface modeling

目    录
摘    要 II
Abstract III
第一章 绪论 1
1.1 概述 1
1.2 逆向造型定义 2
1.3 逆向造型的基本原则 2
1.3.1测点 2
1.3.2 连线 2
1.3.3 构面 3
1.3.4 构体 3
1.4 逆向造型的目的和意义 4
1.5  逆向造型的基本步骤 4
1.5.1  三坐标测量 4
1.5.2 数据的处理 5
1.5.3 逆向造型建模 5
1.5.4 逆向造型的应用 5
第二章 逆向造型常用的软硬件 6
2.1 测量设备 6
2.2 常用的逆向造型软件简介 8
2.2.1 Imageware 8
2.2.2 Geomagic Studio 8
2.2.3 DelCAM公司的CopyCAD 9
2.2.4 PTC逆向软件 9
2.2.5 UGNX 9
第三章 头盔的具体造型过程 11
3.1 对点云数据进行分析 11
3.2点云数据去噪及压缩 12
3.3 曲率分析 12
3.4造型流程图 13
3.5具体构面过程 14
3.5.1首先考虑把点云分成两大块构面 14
3.5.2对曲面进行误差及品质分析 15
3.6 对自由曲面重新分块及构面 16
3.6.1 自由曲面轮廓线的构造 16
3.6.2 构造两块自由曲面 17
3.6.3 对重构的曲面进行误差及品质分析 18
3.7 三维模型重构 20
3.8 曲面片增厚 20
3.9 头盔设计结束语 21
参考文献 22
毕业设计总结 23
致    谢 25