Research On Modeling And Application Technology Of Lung Trachea Based On Reverse Technology

The freeform surface modeling is an important research content in reverse engineering. The precision and quality of modeling play a significant guarantee on manufacturing high quality parts quickly. So it has important theoretical significance and utility value to study freeform surface modeling technique based on scanning point cloud.In this paper, the point cloud data of bronchial sample is scanned by CMM. After analysis and preprocessing, curve and surface model of bronchial sample is established. Finally, the CAD model of sample is obtained and its structure is analyzed to compare bronchial system of human being with the exhaust system of vehicles for the bionic proof on designing a new exhaust system of vehicles.First of all, the three-dimensional point cloud data of bronchial surface contour is obtained by CMM programming. The noise source, noise classification, noise reduction, smoothing, simplification and fitting technique of the data are analyzed and researched. The jump points are removed by using string height difference method and the data is smoothed by weight-adjustable low-pass Gaussian filter. And a new method called multi-point curvature estimation on the basis of three points estimated curvature is developed to finish data simplification.The basic method of surface reconstruction is analyzed, Using the method of triangular surface reconstruction based on triangular Bezier surface, taking Geomagic Studio software as a tool, surface reconstruction of the lung "point cloud" obtained is done, Parameter setting problems of the points to the polygon and the ultimate formation of surface are analyzed. Aimming at the accuracy of the reconstruction problem, the reconstruction geometric error is analyzed quantitatively from the perspective of tolerance band, borrowing the concept of the degree of surface contour. The distribution of the deviation of the reconstruction surface to the "point cloud" is obtained. On the other hand, based on the analysis methods of the surface smoothing degrees and the surface quality, the visual quality of reconstruction surface is evaluated comprehensively combined reflection line analysis diagram, zebra analysis diagram, curvature map and realistic figure of the reconstruction surface borrowing Imageware.Finally, the structural parameters of bronchial sample are obtained by analyzing the anatomy structure and physiological function of the sample. And the automatic expansion and contraction mechanism of bronchial wavy ventilation channel is studied with the environment changing. The bronchial system of human being is contrasted with exhaust system of vehicles to find similarities between the two. So a new exhaust system of vehicles is designed on the basis of wavy ventilation characteristic of bronchial channel.