Study On Key Techniques Of Reverse Engineering Oriented To Rapid Prototyping Manufacturing

RP&M (Rapid Prototyping Manufacturing) is a newly developing technology in the field of manufacturing industry of the time. Reverse Engineering (RE), combined with RPM, may fundamentally change the traditional mode of production design and manufacturing. But, the present technology of RE doesn match the rapid prototyping technology at all. In this paper, the system configuration of RE based on RP&M (RERP) is proposed. It is expounded comprehensively from the aspect of data preprocessing, triangulation, smooth surface construction, STL file information processing , etc. Once realizing the organic integration of RE/RPM, it can greatly improve the ability of Rapid Product Development (RPD). Firstly, according to the characteristic of STL file, the scattered data preprocessing and methods of triangulation are presented. Data repairing based on neural network, automatic boundary point recognition, adaptive kalman filtering, etc, various kinds of technical means are utilitied for solving the difficult problems in data preprocessing. Some methods, such as physically-based triangulation and selective triangulation, are investigated enriching and developing the content of triangulation and improving the grid quality greatly. Secondly, by means of differential geometry, some methods of smooth surface construction are studied systematically. Given the subdivision criterion of initial grid, two techniques of averaged subdivision and selective subdivision are discussed. Resort to the quantitative relationship between subdivision number and allowed error of RE, subdivision becomes more scientific and reasonable. Using the optimum theory. an iterative method of improving surface quality so as to gain quasi-C2 surface is proposed. This scheme is capable of yielding smoother surfaces, if the fairing algorithm is applied one after the other. In addition, there are lots of redundant grids in polyhedral model gained from RE. It is unbeneficial for later treatment of RP&M. Through analyzing all kinds of methods of multi-resolution model, concepts of concentric superface and star neighbourhood are first presented in RE. A new model simplification algorithm, based on local geometry and topology recognition. is developed. It is not only reduce the length of STL file, but also bring convenience for displaying graphics and adding support. Finally, the integration of RP technology and RE is deep investigated. Some problems related with surface model and RP technology is pointed out. The method and data structure of reconsfructing the topology information of STL file are proposed. Also addressed in the paper are issues of the mistake check methods and repairing techniques of STL file. Then an experimental procedure of creating interface file and making the seat prototype of a bike is summarized in detail. The result testifies the feasibility and practicability of the technical line presented in this paper. All of the above-mentioned measures, impact the development for realizing the integration of RE/RPM.