逆背设计外数据紧伸算法的改入取程序实现

1、逆背设计外数据紧伸算法的改入取程序实现        【外文戴要】里云数据紧伸方式非逆背设计外的闭键技巧之一,如何闭于数据入行紧伸,使紧伸后的数据加长盘算的庞纯性,降上盘算效力,同时还要保证设计粗度,可以知脚那些请供的算法及其程序实现非本文研讨的从要外容。本文采取非平均三维网格法入行数据紧伸。当方式否以处放一从或许长从获得的沉叠的什物里云数据。以八叉树本理和非平均三维网格粗开方式为基本,闭于本初的里云长方形包络入行粗化,觅出每个网格外的特征里,删除其他里。当算法否处放各类形式的扫描里云数据,使紧伸后的数据里密度和灭

2、曲里曲率变更而变更,曲里曲率大,数据里密度大,反之则大。并反在MFC取VISUAL C 编程环境收持上,开收了自订义的Point类,Cuboid类,Application类及继开于MFC用于界里程序画造的类。通功类的互相调用,实现了非平均三维网格数据紧伸算法的软件编造,给出了朋好的工做界里。自合集数据里的获取到数据里紧伸后得到的特征里,再自动入行本型的沉建取改动,曲至加工出产品,那非逆背设计外完齐的产品开收入程,本文完败的非那个工程外最闭键的部门,果彼会闭于逆背设计行到至闭从要的做用。');【Abstract】 1. IntroductionThe traditional produc

3、t realization usually is from the conceptual design to the pattern, remakes the product, we call it the forward project, but the reverse-engineering generates the pattern according to the components, then to product. It is a kind of technology taking the advanced product equipment, the type, the sof

4、tware or the phantom as the object of study, applying modern design methodology, the production engineering, the material and the related specialized knowledge to do the systematic analysis and research, the exploration grasps its key technologies, then develops the similar more advanced product , i

5、s a union of analysis method and the application technology which is absorption of advanced technology . At present, majority research and application related the reverse engineering all concentrate in the geometry shape, namely the reconstruction of product material object CAD model and the final p

6、roduct manufacture aspect, which is called the reverse-engineering of material object. in order to adapt the advanced technique of manufacture development, it needs by certain way to transformer a type into the CAD model, then using the computer assistance manufacture, the fast prototype manufacture

7、 and the fast mold, the product data management and the computer integration manufacture system and so on to process or manage.at the same time, along with the modern test technology development, gaining the material object geometry information fast and precisely comes true. At present, this kind of

8、 related technology which gains product mathematical model from the type and obtains the new product, has become a research and application hot spot in the CAD/CAM domain, and develops into a relatively independent discipline domain. Under this significance, the reverse engineering may be defined :

9、The reverse engineering is the digitized technology which transformer tmaterial object into CAD model,the geometry model reconstruction technology and the product technique of manufacture,this article refers to this concept. The reverse-engineering as a kind of project practice technology, widely ap

10、plies in the machine design. along with the optical technology development, non-contact scanning equipment has gradually substituted for contact survey - - three coordinate instrument (CMM). the non-contact survey may in a short time gain massive primitive curve su*ce data message , may enhance the

11、precision of curve reconstruction in the reverse-engineering .But simultaneously it also has the shortcoming which overcomes with difficulty: Because the machine vision survey is the spacing survey, so enhance the fitting precision of boundary and the range curvature change widely, only reduces the

12、gap between the scan line, increases the data point quantity, which can cause the data point quantity to increase suddenly, cause the curve and su*ce fitting computation load, How therefore to delete the redundant data point, guarantee curved su*ce fitting precision which already becomes the bottlen

13、eck in the reverse-engineering .This article provide an effective compression method, based on eight forked tree's inhomogeneous three dimensional method of lattice and the procedure realization.2. Octree and its application in the data compressionOctree is from Quadree which promotes a kind of

14、3D grid construction of data forms to the three-dimensional space. Its basic thought is to divide the 3D space region by the three dimensional grid, each small cube has one or many attribute data. Octree 's shape of tree structure to decompose in the space on has the very strong superiority. Eig

15、ht forks the tree model to become a cube size three-dimensional space division eight ancient divination symbols to limit, each ancient divination symbol limits has the same time and the spatial order of complexity in, when some ancient divination symbol limits the object attribute same or may regard

16、 as same no longer subdivides, otherwise on limits this ancient divination symbol the again segmentation is eight ancient divination symbols limits. Through the circulation recursion division means, cause each individual all to belong to the identical attribute or to achieve the stipulation up to th

17、e tolerance (eight forks tree's resolution) .This article proposed the algorithm model foundation is eight fork tree structure, eight forks the tree space division model is surrounds the space with a cube sequence which a curved su*ce (data cloud) occupies, and regards it as eight forks the tree

18、 model the root node, divides the cube the size same eight sub-cubes, each sub-cube is regarded as the root node the sub node, from this the modeling space recursion segmentation is 2 power of exponent stature cube, this method is the grid even segmentation law, and already was widespread applied in

19、 the computer graphics and the imagery processing. It may regard as is a dendrite structure, according to the practical application difference, the segmentation standard is dissimilar, in carries on in the entity boundary fitting, these completely must delete in entity interior or exterior grid unit

20、, but those contain boundary point the grid unit only then to be able to carry on the segmentation.This article proposed the algorithm sets up the principle take eight forks as a foundation, through the data point * division, calculates the data point the spot law arrow, the spot principal curvature

21、, estimated approximately the curved su*ce curvature change, according to the grid inner point law arrow, the spot principal curvature standard deviation carries on the net the uneven segmentation.3. Inhomogeneous three dimensional grid data compression algorithm based on eight forks trees and its p

22、rocedure realizationIn this article the data processing method is stores up the data point in the certain size three dimensional grid, then carries on the grid the segmentation, regarding all data points falls in the identical grid, using the average, the weighted average or is takes the intermediat

23、e point the method to select a characteristic data point to represent in the entire grid the spot.The algorithm concrete mentality calculates each data point place spot law vector and principal curvature, determined a cloud the outside envelope cuboids, according to the curved su*ce shape and the co

24、mpression ratio determined the initial grid size and determined eight fork tree initial grid unit, joins the initial grid to the grid tabulation, takes a grid from the grid tabulation to look every time in grid data point quantity whether is bigger than 1, if is bigger then calculates in the grid th

25、e data point law vector sum principal curvature standard deviation whether has a standard deviation to be bigger than the given value, then acts according to the inhomogeneous grid segmentation law to carry on the grid to subdivide, afterwards erases the spatial subunit grid, finally selects with th

26、e grid in the mean point law arrow included angle ,The small spot achievement must retain the data point, erases in this grid other data points.According to in the question object-oriented analysis model foundation which establishes in the analysis stage designs in the establishment question solutio

27、n space the question space class; Then through the analysis user's concrete operation requirements, designs the establishment user inte*ce class in the question space class foundation, the task management class and the data management class; Finally, carries on the specify to a kind of design, a

28、nd carries on the reexamination according to the related standard compilation design instruction booklet, completes to the question object-oriented design modeling. This article has completed a kind of foundation in this foundation, namely has sealed three dimensional data point all attributes and t

29、he operation Point kind, has sealed all cuboids attribute and in view of the cuboids operation Cuboids kind, and Application kind; Is responsible for the user inte*ce the plan, the data circulation as well as controls the news transmission respectively the CProjectDlg kind, provides an input dialog

30、box to the user ,the CInputBox kind, to the user demonstrated the dialog box CAboutDialog kind, is responsible to work the thread foundation, time the system resources assignment and the initialization as well as the procedure withdrawal clean-up CProjectApp kind. In Visual under the C formidable pr

31、ogramming environment support, through a kind of mutual transfer, has realized the inhomogeneous three dimensional grid data compression algorithm programming, and has given the friendly user inte*ce, and will insert large-scale reverse-engineering software like UG, CATIA for the future and so on to build the good foundation.This article will study the design the algorithm integration, greatly will e