Data cloud direct reduction in reverse engineering

Based on analyzing the applicability of chord and angle-deviation criterion and enveloping box method, an improved direct data reduction method was proposed, in which two exiting combined-enveloping box methods was applied to construct the segmenting planes, then process the data cloud into structured measured data stored according to the scanning lines; the chord-angle deviation criterion was adopted to reduce the data sequentially. Some typical cases, such as casting molding board, automobile engine cover and human-head sculpture, were chosen to verify this data reduction method. It is found that newly proposed method possesses the advantages of both chord-angle deviation and enveloping box methods and breaks up the limitations of these two methods in case of sharp curvature variations and multiple additional features in measured data. Thus it can be utilized to reduce data directly and efficiently, especially the scattered data with complex additional features.