SUN Zhenguo1,LI Jiafu2,LUO Mingzhe2,LI Yifan1,HU Jiacheng1
1. College of Metrology & Measurement Engineering, China Jiliang University, Hangzhou, Zhejiang 310018,China
2. National Institute of Metrology, Beijing 100029, China
Abstract Propose a displacement measurement method to address the issue of mutual interference between different confocal points in a scanning spectral confocal measurement system. Maintain the independence between multiple measurement channels by using optical fiber bundles and employ optical switches to switch between measurement channels to prevent interference. The system comprises seven focal points arranged in an equilateral hexagon, with six points positioned at the hexagons vertices and one focal point at its center, yielding a hexagon side length of 43.27μm. Displacement measurement experiments indicate an absolute error of less than 0.15μm across all measurement channels and a range of 0～90μm. In experiments involving step surfaces, with two steps of 30μm height difference, the maximum error is 0.16μm. In sphere radius measurements,all seven channels can measure without the need to move the measurement system or the object being measured. A fitted approximation for a sphere with a radius of 5mm yields a maximum error of 80.92μm. Compared with traditional methods, this method shows higher precision and resolution.
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2024, Vol. 45 
