Fernández Pedro, Blanco David, Rico Carlos, Valiño Gonzalo, Mateos Sabino
Department of Manufacturing Engineering, University of Oviedo, Campus of Gijón, 33203 Gijón, Spain.
Sensors (Basel). 2014 Mar 6;14(3):4495-512. doi: 10.3390/s140304495.
Conoscopic holography (CH) is a non-contact interferometric technique used for surface digitization which presents several advantages over other optical techniques such as laser triangulation. Among others, the ability for the reconstruction of high-sloped surfaces stands out, and so does its lower dependence on surface optical properties. Nevertheless, similarly to other optical systems, adjustment of CH sensors requires an adequate selection of configuration parameters for ensuring a high quality surface digitizing. This should be done on a surface located as close as possible to the stand-off distance by tuning frequency (F) and power (P) until the quality indicators Signal-to-Noise Ratio (SNR) and signal envelope (Total) meet proper values. However, not all the points of an actual surface are located at the stand-off distance, but they could be located throughout the whole working range (WR). Thus, the quality of a digitized surface may not be uniform. The present work analyses how the quality of a reconstructed surface is affected by its relative position within the WR under different combinations of the parameters F and P. Experiments have been conducted on AISI 316 wire EDM machined flat surfaces. The number of high-quality points digitized as well as distance measurements between different surfaces throughout the WR allowed for comparing the metrological behaviour of the CH sensor with respect to a touch probe (TP) on a CMM.
锥光全息术（CH）是一种用于表面数字化的非接触干涉测量技术，与其他光学技术（如激光三角测量法）相比具有多个优势。其中，它突出的优势在于能够重建高倾斜表面，并且对表面光学特性的依赖性较低。然而，与其他光学系统类似，CH传感器的调整需要适当选择配置参数，以确保高质量的表面数字化。这应该在尽可能接近工作距离的表面上进行，通过调整频率（F）和功率（P），直到质量指标信噪比（SNR）和信号包络（Total）达到合适的值。然而，实际表面并非所有点都位于工作距离处，而是可能分布在整个工作范围内（WR）。因此，数字化表面的质量可能不均匀。本研究分析了在参数F和P的不同组合下，重建表面的质量如何受其在工作范围内的相对位置影响。已在AISI 316线切割加工的平面上进行了实验。通过在整个工作范围内数字化高质量点的数量以及不同表面之间的距离测量，可将CH传感器与坐标测量机上的接触式探头（TP）的计量性能进行比较。
