基于逆向工程的肺气管建模及应用技术研究

发布时间：2018-03-28 11:43

本文选题：逆向工程　切入点：点云处理　出处：《西安理工大学》2010年硕士论文

【摘要】： 自由曲面造型是逆向工程的重要研究内容,造型的精度和质量是实现快速制造高质量零件的重要保证。因此研究基于扫描点云的自由曲面造型技术具有重要的理论意义和实用价值。论文针对肺气管的实物模型,通过CMM扫描获取样件“点云”数据,经过分析和预处理,建立肺气管的曲线曲面的数字模型,反求出样件的CAD模型并对其结构进行分析,试图找出人体肺部支气管与汽车排气系统相似性,为汽车排气系统设计提供仿生依据。通过三坐标测量机(CMM)编程,获得支气管模型样件表面轮廓的三维点云数据信息,研究了“点云”数据的噪声来源、噪声分类、去噪、数据平滑、数据精简和数据拟合技术。在弦高差法去除“跳点”的基础上,根据“点云”噪声特点采用权重可调的高斯低通滤波器对“点云”进行平滑滤波处理,以三点曲率估计为基础,建立了多点曲率估计法,完成了基于曲率变化的数据精简。分析了曲面重构的基本方法,采用三角Bezier曲面为基础的三边域曲面重构方法以Geomagic Studio软件为工具,对获得的肺气管“点云”进行了曲面重构,重点分析了从点到多边形以及最终形成曲面的参数设置问题。针对重构精度问题,论文借用曲面轮廓度的概念,从公差带的角度对重构几何误差进行了定量地的分析,获得了重构曲面对“点云”的偏差分布。另一方面,在分析曲面光顺度及曲面品质分析方法的基础上,借用Imageware结合重构曲面的反射线分析图、斑马线分析图、曲率分布图和真实感图,对重构表面的视觉品质进行了综合评价。论文在分析支气管的解剖结构及其生理功能的基础上,获得了肺气管的结构参数。研究了支气管通气波纹状管道随环境改变而自动扩张和收缩的机理,与汽车排气系统的功能进行对比分析,找出二者之间的相似点,进而提出了一种基于肺气管结构的管壁为波纹状的汽车排气系统设计思想,为汽车排气系统设计提供了一种新的思路。
[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 .

【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R329

【引证文献】