Model Reconstruction And Error Analysis Based On Scattered Points In Reverse Design

As an important means of the development of novel product and the absorption of advanced manufacturing technology, special attentions have been paid to the reverse engineering technology by the industries of many countries. And a great deal of extensive research achievements has been obtained and used widely. Model reconstruction is an important issue in the process of point data preprocessing to the reverse engineering. The feasibility of the follow-up design is directed to the reconstruction accuracy.The basic concepts of reverse engineering and related key technologies were described firstly, and the multi-view registration and model reconstruction was researched with emphasis. Based on the actual needs to the reconstruction of scattered data model,the measurement of scattered data, the data processing of the multi-view and surface reconstruction techniques were studied to further enrich or improve the content of reverse engineering.Firstly, the alignment of multi-point data in the model reconstruction process was put forward. The multi-view registration techniques based on the reference point and feature-based were described in details. Based on the combination of the two techniques, the multi-multi-view data of the motorcycle hood were put together with a good effect by the software imageware. The multi-multi-view data of the airplane model was directly aligned by the ICP algorithm. And the rotation and translation matrices were obtained. The aligned point cloud data were input the CAD modeling software by the IGES file to provide data support for the follow-up model design.Based on the whole integrated data, the mathematical models including Bezier, B-spline, NURBS curves and surfaces, which are widely used in the reverse engineering modeling technology, were discussed. In order to reconstruct curve gear model, the contour line was fitted before the model reconstruction. However, the CAD model reconstruction of the motorcycle hood was directly carried out by the surface reconstruction. The error model analysis in the pretreatment process of the point cloud to the curve, surface reconstruction were carried out to obtained the error model of the reverse engineering. And the overall error of the model reconstruction was control within 0.5mm The CAD model was reconstructed to meet the accuracy requirements for the follow-up designs and applications.