Miniaturized interferometric 3-D sensor for shape measurement inside of cutting lathes

We propose an in-situ coordinate measurement machine based on a Mach-Zehnder interferometer. The sensor system enables the simultaneous measurement of axial distance and lateral velocity at rough and fast rotating objects. This allows to guarantee ever-decreasing tolerances, measurements of surface profile, roundness and absolute diameter of workpieces inside of lathes. With a camera based detection, measurement uncertainties below 100 nm can be achieved. Furthermore, cameras allow an in-situ calibration of the measurement system. By employing coherent fiber bundles, a robust probe without active parts in the lathe was realized. An extended measurement volume was achieved for a 3-D shape measurement without scanning. (C) 2018 The Authors. Published by Elsevier Ltd.