The Method For Processing Point Cloud Data Of Automobile Cover And The Techniquesnet For Networked Collaborative Design

Complex automotive body panels constitute the important parts of the automobilebody structure. Created through the reverse engineering of complex automotive bodypanels digital model used in the design of the body structure, body stiffness analysis anderror detection, the traditional kind of design model from a CAD drawing to change thedigital design model for measurement-based modeling, greatly improve the efficiencyof product design and shorten the product design cycle, and provides a new way forproduct development and design. However, on the one hand the continuousimprovement of reverse engineering digitization, automation and measurement accuracyof the measuring equipment, led to the rapid growth of the model for measuring theamount of data; other hand, due to the presence of auto cover a large area, thin, complexshape products, the measurement modeling using reverse engineering design have ahigher degree of difficulty and complexity, and therefore, there are a lot of issues needto delve into; such, the model has a very complex geometry and topology measurementmodel the existence of the scan point cloud data stacked and the presence of certainareas of the point cloud data missing, as well as the complexity of the modeling processrequires collaborative design support. The papers faimed at reverse engineering of theautomobile cover the keyconduct further research, The main contents are as follows:①Contrary to the characteristics of the auto cover, analysis of the pros and consof the different types of scanning equipment in reverse engineering, conducted acomprehensive study of the auto cover data acquisition scan method;and auto cover datapreprocessing technology and grid technologyrelated theory.②Auto cover large area, thin products, so that it may exist in the point cloud dataacquisition process stacked point cloud phenomenon, while producing the large stack ofpoint cloud data processing will consume a lot of time into curved the relatively largeshape errors. Hierarchical point cloud data preprocessing car cover is particularlyimportant. In this paper, a car cover hierarchical processing point cloud data slicingalgorithm.The algorithm first determines the position of the the cascading point clouddata, and then along the model of the three-dimensional coordinates of its multi-layeredslice, then each slicing points cloud is sampled to determine the point of the crests andtroughs in the sampling range, and generates a point cloud of the dividing line of thelaminate sample through its （also become midline）, and the method according to the best linear determine chamfered position separator segment, which will automaticallythe cascading point cloud data separation.③The auto cover point cloud data acquisition process, because of the differentmeasurement principle, measurement limitations of the software as well as humanfactors because there will be holes in the point cloud data defects phenomenon, leadingto incomplete point cloud data features late to establish a three-dimensional model ofdistortion. In this regard, this paper proposes an automobile cover the hole defects ofpoint cloud data supplement algorithm, the algorithm is to establish the mappingbetween the scan head, two-dimensional images and three-dimensional grid of pointcloud data, through the hole boundary extraction method extracted data of the edge ofthe holes of the grid point cloud data, the edge point is mapped to a two-dimensionalpicture, by a two-dimensional picture of the pixel value and a gradation value of themapping point stratified, so that the point cloud data of the three-dimensional spatialgrid repair.④Complex auto cover modeling process needs to be collaborative design support,such as the data side online interaction with customers, tracking customer datainformation and timely feedback suggestions information. In this regard, theestablishment of an Internet-based remote car cover reverse engineering design networkshared services platform, Application of the platform to achieve human-computerinteraction measurement modeling process, customers can assess the entire digitizationprocess online, to achieve the purpose of the collaboration between enterprises andproduct design.Finally, this work is a summary and outlook of future research directions.The content of the above-mentioned research, validation services for the large andmedium-sized enterprises of Dongfeng Motor, Lifan cars, and achieved remarkableeconomic and social benefits.