Skip to Main Content
This paper presents a vision-based measurement methodology which utilises a micrometre calibration slide and confocal microscope. The technique is suitable for measurement of both angular and linear displacements. The algorithm presented in this paper overcomes the shortcomings of limited CCD pixel count and image size, out of focus areas at the boundaries of the image, and vertical motion of the slide out of the focal plane. Many parameters can be changed within the setup, allowing the resolution and range of measurement to be modified for a given application. Experimental verification has been performed in an angular measurement configuration, demonstrating noise-limited linear and angular resolutions of 0.04 μm and 0.29 μrad, respectively.