Robotic measurement has emerged as a prominent method for the quality control of large-scale metal workpieces. However, it faces two significant challenges: optical measurement of homogeneous high-reflective metal surfaces and point cloud registration on local featureless surfaces. To address these challenges, this study presents a cooperative optical profiler that integrates a certain number of light-emitting diodes into a conventional fringe projection profiler. This integration enables the use of photometric stereo, providing comprehensive and accurate surface normals of machined metal surfaces with intricate details such as tool marks. The surface normal was then fused with the initial point cloud from the fringe projection profiler to yield complete local measurement results. In addition, a geometry descriptor incorporating the surface normal was designed to improve data registration accuracy. Experiments based on six small workpieces with the combination of three shapes and two materials and a large freeform workpiece demonstrated that the proposed method achieved measurement accuracy close to that of a coordinate measuring machine.

中文翻译：

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基于条纹投影与光度立体相结合的协同光学轮廓仪的高反工件机器人测量系统

机器人测量已成为大型金属工件质量控制的重要方法。然而，它面临着两个重大挑战：均匀高反射金属表面的光学测量和局部无特征表面上的点云配准。为了解决这些挑战，本研究提出了一种协作光学轮廓仪，它将一定数量的发光二极管集成到传统的条纹投影轮廓仪中。这种集成支持使用光度立体，提供加工金属表面的全面且准确的表面法线以及工具痕迹等复杂细节。然后将表面法线与来自条纹投影轮廓仪的初始点云融合，以产生完整的局部测量结果。此外，还设计了包含表面法线的几何描述符来提高数据配准精度。基于三种形状和两种材料组合的六个小工件和一个大型自由形状工件的实验表明，该方法实现了接近三坐标测量机的测量精度。