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Non-contact adaptive sampling for unknown free-form surface
based on double-probe integration |
| LU Ke-qing, WANG Wen, CHEN Zi-chen |
| Institute of Advanced Manufacturing Engineering, Zhejiang University, Hangzhou 310027, China |
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Abstract In order to digitize unknown freeform surfaces accurately, quickly and rationally in reverse engineering, a new noncontact adaptive sampling strategy based on doubleprobe integration was presented. The method was characterized by integrating two laser probes abreast as leading probe and end probe respectively. A piece of gobo was used to shut out reflected light to avoid light interference with each other. During the sampling time, at the measuring direction, the leading probe was applied to detect the measuring path in front of the end probe. The data acquired by the leading probe was processed instantaneously to extract the curvature feature of the measured path. The obtained information was subsequently used to generate rational sampling spacing and guide adaptive sampling for the end probe. While at the crosssection intake direction, section angle analysis algorithm was done to subdivide the crosssection if it was needed. Simulation and experiment results indicate that the sampling points generated by the end probe can be laid out rationally according to the curvature feature of the surfaces, therefore the sampling efficiency and accuracy are improved significantly, and effective sampling data can be offered for model reconstruction.
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Received: 30 March 2009
Published: 21 September 2010
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基于双测头组合的未知自由曲面自适应采样
在逆向工程中为了准确、快速、合理地获取未知自由曲面的表面数据,提出一种基于双测头组合的非接触式自适应采样方法.并列组安装2个点激光测头,分别为前端测头和后端测头，利用遮光布阻挡反射光消除两测头之间的测量干扰.在逐行采样过程中,在扫描方向上前端测头用于探路测量,系统实时地对探路测量数据进行处理与曲线拟合,根据拟合曲线的曲率特征为后端测头规划合理的采样间距,后端测头以探路结果为指导完成自适应采样.在测量截面进给方向上,通过截面间夹角分析,自适应地细分测量截面.仿真与实验结果表明,该方法能根据曲面特征合理地布置采样点,能有效提高曲面数字化的效率与精度,为模型重建提供合理的测量数据.
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