Point Data Repairing And Surface-reconstruction In Reverse Engineering

Reverse Engineering (Reverse Engineering RE), also known as reverse engineering, considered as a feedback-loop design from upstream to downstream, and then develop more advanced technology products, as well as absorb advanced technologies from series of analytical methods and application technology.As an important method of developing new products and absorbing advanced technologies. Reverse-engineering (RE) is understudied by industrial field and academia in many countries. So far, it have applied in wide range of fields such as vehicles, mold , household appliances , the restoration and imitation of cultural heritage. Industrial engineers, in the use of free-form surface reconstruction technique, can significantly shorten the product design and manufacturing cycles, improving product development efficiency.Modeling of the products in Reverse Engineering is in accordance with the following general procedures: acquire the data-point cloud through measuring the product, Pretreatment data-point, CAD model reconstruction. In these steps, The quality of point cloud and surface fitting reconstruction program eventually to be a crucial factor affecting the quality of CAD models.During the scanning process by 3D laser scanner, due to the limit of scan target site, scanning speed and time , data from certain parts of the 3D object was not in integrity, which caused defects of 3D data. Some scholars have already given a cross-section measurements remedy , used to coordinate the equivalent of a particular axis direction, in this way,3D data into 2D curve fitting based on neural network approach. But its application is very narrow, Because the nature of the cloud patterns must followed to a stringently limit. This article will explore another unorganized point cloud repairing method based on BP neural network, and compared these two methods. At last ,give an introduction for the methods on will be of various types of cloud shows targeted for repairing incomplete data.In addition, the surface fitting programs in actual engineering can divided into two major categories :one is directly rebuild the surface base on professional software, the other is using CAD software to Complete the surface-reconstruction based on data point cloud, such as Pro-E. I-DEAS and UGII. These existed programs are not suited to deal with big amount of data point or have compatibility problems with CAD soft wares. This article will explore a new surface fitting program, taken into account of two items: professional reverse software's processing ability on data point cloud and CAD software's large high-quality surface fitting means, which also have good compatibility features with other CAM soft wares. For Specific, the fitting of the curve and the surface are under different environments. This strategy resolve these contradictions. and the merits of the two programs are integrated. This article gives a rather good treatment process, and also have actual value in implementation.Research shows that: the three-dimensional artificial neural network repairing on data-point cloud achieved good results, enriched the forms of repairing ways; The new surface fitting program greatly overcome the shortcomings of the traditional program, give a valuable exploration which have actual implementation value in engineering.