反求工程中的数据筛选与优化的研究

Analysis of Data Selection and Optimization in Reverse Engineering

在含复杂曲面的产品反求工程中,通过测量所获取的数据点云通常十分庞大,且具有一定的杂乱性和冗余性,这样的数据不利于定义曲面和产生CAD/CAM数据库数据.针对这些问题,本文利用测量数据的特征线输入技术,降低了测量数据量;并提出了弦切角偏差法对这些测量数据进行过滤筛选,确保生成曲面的数据的有效和规则;同时利用参数样条函数对过滤筛选后的数据进行拟合优化,将数据函数化,以更利于曲面的生成,且能利用数据的函数表达选择优化数据点的数量,并控制生成曲面的质量.

The data obtained through surveying in reverse engineering are enormous and complicated. Apparently, data of this kind are unfavourable to surface definition and the obtaining of the data of CAD/CAM. The inputing technique of the feature line based on measure data was applied to improve the efficiency of measure data, and a deviation method for the arc was provided to filtrate and select the measure data so as to get effective and regular data to construct the surface. Parameter-spline function was applied to optimize the data, the data of the function was available to construct the surface, and the function expression of the data can be used to choose the amount of optimizing data. Thus the quality of the surface can be controlled effectively.