三次元自由曲面の非接触形状測定センサの開発研究 (第1報)

光リング式センサの解析

抄録

The purpose of this paper is to develop a non-contact profile sensor which will be able to measure 3-D free-form metal surfaces as well as 3-D model shapes. The proposed profile sensor called optical ring image sensor has two major advantages. First, reflection light from a target surface in optical axis can be detected in all direction using a ring slit. Second, the radius of optical ring image is linearly proportional to the displacement of the surface in optical axis. From computer simulation by means of ray-tracing method, this sensor makes it possible to measure the displacement of a target surface within an accuracy of ±20 μm for inclined metal surface up to ± 45 degrees, even though it exists specular reflection. Moreover, it is possible to measure acculately the displacements in edges because the size of optical ring image is unaffected by edge profiles.