Study On Rapid Development Technology For Complex Shape Product Based On RE/RP System Integrating

All the Chinese enterprises will be thrown into the strongly global competition environment after China become a WTO member. How to enhance their ability about new product innovation as fast as possible is a magic weapon for they to win the global competition. So that, three topics in rapid development technology for complex shape product are studied in this paper: key technology for complex shape product reverse engineering(RE) modeling, integrating technology between RE system based on triangular Bezier surface (TBS) modeling and RP system, and investigation of rapid development system frame for complex shape product.In the study on key technology for complex shape product RE modeling, according to the characteristics of complex shape product, the reverse engineering CAD hybrid-modeling technology is proposed to build the product model with complex shape. On the one hand, although the commercial CAD/CAM system that based on NURBS surface theory is reliable and possesses strong functions, it isn't very suitable for RE CAD modeling. On the other hand, the RE-SOFT software, a special software for RE modeling based on TBS theory is difficult to meet the product developing. Therefore, the reverse engineering CAD hybrid-modeling technology has to combine two kind of system to reach the goal of reducing CAD modeling process.According to the requirement of the reverse engineering CAD hybrid-modeling technology, a series of problems such as data capture and data preprocessing are investigated and solved. The research results include the follows: present some rules for selecting measuring method according to the characteristics of product, study some problems in data preprocessing such as noise removing, probe radius compensation, edge data extracting, sun-regions merging, and local data mending or re-sampling etc.To ensure the part CAD models being built and assembled accurately at dimension and shape in RE modeling application, three kinds of model modifying techniques are presented such as model-based modifying, drawing-based modifying and physical model-based modifying. Using these modifying methods, the RE CAD model of parts can meet the assembly andaccord with the part drawings or (and) physical model in both of dimension and shape. To design the local features in product digital modeling, some surface local features are assorted and defined. Furthermore, several methods for surface local features design are proposed such as the treatment of CAD model edge features, design of the near-edge surface features, and design of the inner-surface feature.On the integrating technology between RE system based on TBS modeling and rapid prototyping (RP) system, the differences of some current integrating technology are researched, and the RE/RP systems integration technology by converting the TBS surface model into STL files is studied, and this technology is realized at a prototype system. In this technology, a theory which can be used to divide the TBS's base surface patch into triangle patches or unite several TBS's base surface patches into one triangle is presented, and some problems concerned with dividing the base surface patch into triangle patches are studied and solved such as cracks between triangle patches, computing the number of segmenting of the edge at base surface patch, computing the dividing number of the base surface patch, generating the triangle patches etc. How to combine several TBS's base surface patches into one triangle is also studied and solved. The prototype system realized all the above technologies, and the TBS can be converted into STL model by uniform dividing or optimized dividing methods, and two kinds of STL files, i.e. binary file and ASCII file can output. In this way, the RE/RP systems integration based on TBS model is successfully realized.Finally, a frame of RDSFCSP (rapid development system for complex shape product) is presented based on the integration of RE/RP systems. A remote product developing technology center (RPDTC) is the most important partner in this...