A Study Of Reverse Engineering Technology As Well As The Parametric Design Of Body Panel Surface

With more than ten years improvement, keeping along with the international trend, the integrated technology has got a large advancement. Nowadays, the automotive development cycle has been continually shorten, and the models of new car have emerged continuously; moreover the update the update of the type of cars is mainly about the update of their bodies, so body development occupies a pivotal position in the fierce competition in the market.Generally speaking, that there is a big gap between our national automotive industry technology and othersËŠ.In these technologies, a computer-aided design technique is the most effective measures which can short the development cycle in auto production. Computer-aided design has been rapid developed broadly at aboard, but we only apply the software which was introduced. So we hope we can absorb it and weed though the old to bring forth the fresh, such as practicality digital technology, data disposing and so on. Meanwhile, the existing CAD systems are in common use, which provide the methods of product design. The type of body is fixed and it have continuity and similarity, so a special parametric CAD system which can be carry out exploiting a specific body is very significant .The topic is supported by the Science and Technology Department of Jilin Province. This scientific research project is to research a method that can efficiently distill the point data cloud feature, and use it to build the parametric model. This system can transform the point data cloud into digital model, namely speedy rebuild the surface and ensure imitate precision simultaneity. That is in order to quicken the speed of product design, enhance the quality and efficiency in rapidly produce.According to parametric design, if we combine the features of design with parametric design, use a more complete semantic featured descriptors and make feature itself contains parametric changes in the member variables and member functions, we will use object-oriented technology in the description of features, with adjusting the products in mix, size, then driving features its own, we can realize the production of feature-based parametric design. The core of parametric design in body panel is to establish the parameters of the model. The parameters used to describe the body panel such as shape, size and so on. The structural design, modification, storage and management of these parameters can be passed to deal with. As a result of the feature-based parametric drawing complex shapes of the body panel design work will become easier.The main contents are briefly described below:Chapter 1: Introduce the definition of reverse engineering and put forward some disadvantages. As the significant improvement of laser scanning and structured light, a viable option in reverse engineering brings us lots of data point. And these point data cloud are the foundation of surface feature distilling and surface rebuild. At last, point out the basic technology of the main content and significance of this paper.Chapter 2: Firstly introduce some popular methods of features distilling and surface rebuilding at present. And then describes Visual C + + 6.0 of functions and features as a development tool, and which MFC is introduced simply. Finally introduce a summary of the features of C + + language.Chapter 3: Based on the arithmetic order, the paper in this chapter presents the course of picking out character-data point from large numbers of point data cloud. The course mainly includes partial scanning beam-based triangulation method, in which shows the process of how to compute a data point normal vector and principal curvature, at last explains the technique of cite a adjust scene for the sake of analyses the cube after gain the surface geometry message.Chapter 4: This chapter constructive bring forward the partitioning principle of scanning-surface in the reverse engineering rebuild surface technology that basic outline has known. A foundation of NURBS and based on the ACIS geometric modeling platform, develops a body panel parametric design system. The system is quite complicated shape of the surface space to describe the ability to simultaneously address the problem of automatic mosaic surfaces, and parametric design with the features accessible to the world through the human body to form the panel surface parameters changes, adjusting the shape of surfaces.Chapter 5: The last chapter deals some problems about the reverse body design point cloud data processing and parameterizations surface rebuild. Because the establishment of the project is the provincial Science project, and applied for a patent, not source code by code, however, the use of the type and associated procedures for a detail description of the function and along with the outcome document.In a word, this paper is a useful exploration on the combination of feature-based parametric design of the body panel design and picking out character-data point from large numbers of point data cloud. The level of ACIS software platform and object-oriented technology are developed clearly. The software is maintenances and expanded easily. This paper brings a new method and thought which are feature-based parametric design of body panel. And this paper has some valuable references.