The Research Of Surface Reconstruction In Reverse Engineering Based On Characteristic Surface

In view of the process of reproducing of actual details in reverse engineering, a new process is proposed in this paper in which the surface of details is dividing by character in its measurement and reconstruction. According to this process, the key technology which including the characteristic measurement of surface, the pretreatment of data getting by line scan, the character expression and fitting of curve and surface, the characteristic identify of surface and translation from the model of surface to CAD.In the characteristic measurement of surface, a method of surface' s self-adoption-character measurement is adopted in the paper to achieve the distribution of data' s density. The formula of coordinate transformation is educed and the calculate process in data fitting is proposed.An isolated point' s statistic excluding method is proposed in this paper to eliminate crassitude error in clouding data, which include plenty of oddity data. The method based on the distance between two neighbour points can eliminate the data beyond normal distribution. A error limitation of angle and chordal highness method is used to filtrate clouding point.The methods that represent geometry elements such as line, circle and arc, plan, cylinder, cone and sphere in NURBS form are studied. Meanwhile, the calculating process that interpose to NURBS curve and surface are advanced. To the processed surface, the paper brings forward a method to distill its character (plan, cylinder and sphere) by the main curvature of surface using its local differential coefficient geometry characteristic.According to the calculating methods in the paper, combining converting to CAD model, a application is completed using 00D technology, it base on Windows 2000 operating system, use VC++6.0 and OpenGL three-dimension graph standard as exploiting tools and can dispose the imported point data from outsides and export surface data in system as 3DS form.