本文選題：點云數(shù)據(jù) + 造型件特征線��； 參考：《長安大學》2014年碩士論文

【摘要】：對現(xiàn)有產(chǎn)品或樣機外觀造型件進行仿制或改良，通常應用逆向工程方式進行。采用三維測量設備對造型件外表面進行測量，獲取三維片點云數(shù)據(jù)，對片點云數(shù)據(jù)應用專用軟件進行拼接、修整等處理，得到造型件的點云數(shù)字模型，應用數(shù)模進行造型件仿真與創(chuàng)新是逆向設計的主要過程。 文中根據(jù)造型件數(shù)模創(chuàng)建過程，對影響造型件數(shù)模精度的因素及其控制方法進行了研究。首先應用三掃描儀VIVID910對產(chǎn)品造型件（文中取某電動車前臉）進行外表面片點云數(shù)據(jù)采集，應用InnovMetric Software逆向設計軟件對片點云數(shù)據(jù)拼接、去噪、修補、多視對齊、精簡、光順與分割，獲得低精度的造型件數(shù)字模型。對該數(shù)模按造型件幾何形態(tài)特征與數(shù)模精度要求，應用InnovMetric Software軟件構建一組特征平面（其數(shù)量與建模精度有關），提取特征平面與造型件數(shù)模的截面線，即為造型件的幾何特征線。同樣根據(jù)特征線特點與建模精度要求，在每條特征線上取一組特征點，將其作為特征線的型值點。根據(jù)造型件區(qū)域分割，同一區(qū)域的特征線取相同數(shù)量的特征點，分別用B樣條曲線擬合各區(qū)域特征線，探討造型件特征線按區(qū)域的統(tǒng)一參數(shù)化表示方法。 集成MATLAB2010b軟件、Microsoft SQLServer2005數(shù)據(jù)庫技術，研究產(chǎn)品造型件特征線信息庫系統(tǒng)開發(fā)方法與技術，使產(chǎn)品造型件眾多特征線的信息、幾何曲面信息實現(xiàn)自動化管理。 以造型件外表面幾何特征線上的特征點為型值點，應用積累弦長參數(shù)化方法、最小二乘法計算滿足精度要求的控制點，構造B樣條曲線，，用該B樣條曲線代替特征線。造型件幾何曲面擬合可看作兩階段B樣條曲線擬合，即先對橫向的每一特征線進行B樣條曲線擬合，以此為基礎，再在縱向進行B樣條曲線擬合，即可構造出造型件外表面的近似網(wǎng)格曲面。在Pro/E中應用曲率分析等對重構曲面進行誤差分析，探討了建立了給定精度的造型件曲面重構方法與技術。 應用軟件UG自動生成實體圖案，裝飾電動車前臉（Matlab數(shù)模）生成新的前臉造型方案，將Matlab數(shù)模以Pro/E軟件為橋梁保存為STEP格式。數(shù)模與實體圖案以軟件犀牛插入打開，通過UV展開功能實現(xiàn)實體圖案與電動車前臉的結合。 應用造型件創(chuàng)新方案數(shù)模直接進行注塑模具設計。在Pro/E軟件中通過布爾運算實現(xiàn)型腔和型芯數(shù)模構建，并用Pro/E NC模塊、后置處理模塊編制能被數(shù)控機床控制系統(tǒng)識別的數(shù)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.
【學位授予單位】：長安大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TB472

【參考文獻】

相關期刊論文 前10條

1 譚偉;;基于復合測量方式的摩托車擋風罩逆向設計[J];工程塑料應用;2008年01期

2 胡敏捷;張毅;孫慶文;;船舶艙室點云模型重構技術研究[J];船舶設計通訊;2010年02期

3 孫昆峰;MATLAB和數(shù)據(jù)庫的連接[J];電腦開發(fā)與應用;2001年04期

4 樂英;王璋奇;韓慶瑤;;基于非均勻有理B樣條曲面重構汽輪機扭曲葉片[J];動力工程學報;2010年12期

5 席平;胡畢富;;渦輪葉片模具三維模型重構及誤差分析[J];工程圖學學報;2011年02期

6 戴能云;廖平;王建錄;劉學云;;基于Matlab的復雜曲面形狀誤差評定[J];測控技術;2010年06期

7 ;Constructing iterative non-uniform B-spline curve and surface to fit data points[J];Science in China(Series F:Information Sciences);2004年03期

8 程仙國;劉偉軍;張鳴;;特征點的B樣條曲線逼近技術[J];計算機輔助設計與圖形學學報;2011年10期

9 雋峰;黎小間;高建華;王金珠;;B樣條曲面擬合方法在人體測量中的應用[J];計算機應用研究;2007年05期

10 羅大兵,高明,王培俊;逆向工程中數(shù)字化測量與點云數(shù)據(jù)處理[J];機械設計與制造;2005年09期

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