The Research On Rapid Development Technology Of Complicate Curved Surface Porduct And Its Application In Motorcycle Covering Parts

Manufacturing industry plays a crucial role in the high-speed development of national economy. However, there is a long way for us to go to keep up with the world advanced level. Since 1990s, with the globalization of manufacturing industry escalating, the tempo of market quickening, life cycle of a product is constantly shortening. Therefore, the enterprises must pick up the speed of product development in order to survive in the keen competition of market. Automobile and motorcycle industry is an important part of manufacturing industry. There are a lot of covering parts composed of complicate curved surface, which are of strict outward appearance criteria. The characteristic of the shape of these complicate curved surfaces and the individual requirements of market determined the difference of development means comparing with the traditional pattern. In this issue, after a comprehensive analysis of this kind of products, the rapid development of the covering parts of motorcycle is taking as the object to study the pattern of rapid development of complicate curved surface, of which Reverse Engineering and Rapid Prototyping and Manufacturing are the key enabling technologies. The research is as follows:1. The Model DigitizingThe method of model digitizing not only influences the speed of development, but also indirectly determines the quality and speed of the reconstruction of curved surface. In this paper, it studied the digitization strategy of complicate curved surface utilizing the one-level fuzzy comprehensive judgment method. Moreover, taking the fatlute model of the covering parts of motorcycle for an example, it discussed the measurement plan method of prototype and the process of data handling. 2. Pretreatment of Points Cloud According to the characteristic of scattered point cloud data, the issue elaborated in detail points cloud registration, which was based on the shape characteristic matching. Also, it studied the error correction and the data optimization method of scattered data, and compared the filtration method of multi-noise with the simplified method of data to find out the measurement plan of data that can satisfy the practical application. At the same time, on the basis of the need of the reconstruction of the curved surface, it researched the extract method of the characteristic of point cloud and the fashion of bits and pieces of curved surface.3. Reconstruction of Curved SurfaceFirst of all, from the point of engineering application, the effect of various parameters, which come from the curve of NURBS and the method of curve modeling, is discussed on the curve and the quality of reconstruction of curved surface. Then the reconstruction of curved surface of the covering parts was taken for an example, and the emphasis is laid on the identification and extraction method of the characteristic and the boundary, and the reconstruction method of curved surface. Meanwhile it was given emphasis to the partition strategy of the data of point cloud, the forward direction design of the process of RE, and so on. Besides, the quality of the reconstruction of curved surface was evaluated by accuracy, curvature and lighting-based evaluation measures.4. Rapid Development of Complicate Curved Surface Product Based on RPMAccording to the characteristic of each RPM process, the thesis discussed the adaptability of RPM technology to the complicate curved surface product from the view of material, accuracy, efficiency and model characteristic, and the application of direct tooling and indirect tooling in the rapiddevelopment of covering parts. Finally, a rapid development pattern of complicate curved surface based on RPM is established.