本文選題：逆向工程　切入點(diǎn)：點(diǎn)云處理　出處：《西安理工大學(xué)》2010年碩士論文

【摘要】： 自由曲面造型是逆向工程的重要研究?jī)?nèi)容,造型的精度和質(zhì)量是實(shí)現(xiàn)快速制造高質(zhì)量零件的重要保證。因此研究基于掃描點(diǎn)云的自由曲面造型技術(shù)具有重要的理論意義和實(shí)用價(jià)值。 論文針對(duì)肺氣管的實(shí)物模型,通過CMM掃描獲取樣件“點(diǎn)云”數(shù)據(jù),經(jīng)過分析和預(yù)處理,建立肺氣管的曲線曲面的數(shù)字模型,反求出樣件的CAD模型并對(duì)其結(jié)構(gòu)進(jìn)行分析,試圖找出人體肺部支氣管與汽車排氣系統(tǒng)相似性,為汽車排氣系統(tǒng)設(shè)計(jì)提供仿生依據(jù)。 通過三坐標(biāo)測(cè)量機(jī)(CMM)編程,獲得支氣管模型樣件表面輪廓的三維點(diǎn)云數(shù)據(jù)信息,研究了“點(diǎn)云”數(shù)據(jù)的噪聲來源、噪聲分類、去噪、數(shù)據(jù)平滑、數(shù)據(jù)精簡(jiǎn)和數(shù)據(jù)擬合技術(shù)。在弦高差法去除“跳點(diǎn)”的基礎(chǔ)上,根據(jù)“點(diǎn)云”噪聲特點(diǎn)采用權(quán)重可調(diào)的高斯低通濾波器對(duì)“點(diǎn)云”進(jìn)行平滑濾波處理,以三點(diǎn)曲率估計(jì)為基礎(chǔ),建立了多點(diǎn)曲率估計(jì)法,完成了基于曲率變化的數(shù)據(jù)精簡(jiǎn)。 分析了曲面重構(gòu)的基本方法,采用三角Bezier曲面為基礎(chǔ)的三邊域曲面重構(gòu)方法以Geomagic Studio軟件為工具,對(duì)獲得的肺氣管“點(diǎn)云”進(jìn)行了曲面重構(gòu),重點(diǎn)分析了從點(diǎn)到多邊形以及最終形成曲面的參數(shù)設(shè)置問題。針對(duì)重構(gòu)精度問題,論文借用曲面輪廓度的概念,從公差帶的角度對(duì)重構(gòu)幾何誤差進(jìn)行了定量地的分析,獲得了重構(gòu)曲面對(duì)“點(diǎn)云”的偏差分布。另一方面,在分析曲面光順度及曲面品質(zhì)分析方法的基礎(chǔ)上,借用Imageware結(jié)合重構(gòu)曲面的反射線分析圖、斑馬線分析圖、曲率分布圖和真實(shí)感圖,對(duì)重構(gòu)表面的視覺品質(zhì)進(jìn)行了綜合評(píng)價(jià)。 論文在分析支氣管的解剖結(jié)構(gòu)及其生理功能的基礎(chǔ)上,獲得了肺氣管的結(jié)構(gòu)參數(shù)。研究了支氣管通氣波紋狀管道隨環(huán)境改變而自動(dòng)擴(kuò)張和收縮的機(jī)理,與汽車排氣系統(tǒng)的功能進(jìn)行對(duì)比分析,找出二者之間的相似點(diǎn),進(jìn)而提出了一種基于肺氣管結(jié)構(gòu)的管壁為波紋狀的汽車排氣系統(tǒng)設(shè)計(jì)思想,為汽車排氣系統(tǒng)設(shè)計(jì)提供了一種新的思路。
[Abstract]:Free surface modeling is the important research content of reverse engineering . The precision and quality of modeling are the important guarantee for the rapid manufacture of high quality parts . Therefore , the research of free surface modeling based on scanning point cloud has important theoretical significance and practical value .



According to the physical model of lung trachea , the data of sample " point cloud " is acquired through CMM scanning , the digital model of curved surface of lung trachea is established through analysis and pretreatment , the CAD model of sample is established and its structure is analyzed , and the similarity between the lung bronchus of human body and automobile exhaust system is sought to provide bionic basis for the design of automobile exhaust system .



The three - dimensional point cloud data information of bronchial model sample surface contour is obtained through three - coordinate measuring machine ( CMM ) programming . The noise source , noise classification , de - noising , data smoothing , data reduction and data fitting technique of " point cloud " data are studied .



This paper analyzes the basic method of surface reconstruction , uses the triangular Bezier surface as the base , uses the Geomagic Studio software as the tool , analyzes the problem of parameter setting from point to polygon and finally forms the curved surface . On the other hand , based on the analysis of the surface profile degree , the paper obtains the deviation distribution of the reconstructed surface to " point cloud " . On the other hand , based on the analysis of the surface smoothness and the surface quality analysis method , the reflection line analysis diagram , the zebra line analysis chart , the curvature distribution map and the realistic map of the reconstructed surface are used to comprehensively evaluate the visual quality of the reconstructed surface .



On the basis of analyzing the anatomical structure and physiological function of the bronchus , the structural parameters of the lung trachea were obtained . The mechanism of automatic expansion and contraction of the corrugated pipe of the bronchus was studied , and the similarity between them was found out .

【學(xué)位授予單位】：西安理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2010
【分類號(hào)】：R329

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 張偉鳳;舌側(cè)正畸數(shù)字化排牙及個(gè)性化托槽結(jié)構(gòu)設(shè)計(jì)與分析[D];山東大學(xué);2011年

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本文編號(hào)：1676182