Tantau, MathiasMorantz, PaulShore, Paul2021-07-292021-07-292021-05-19Tantau M, Morantz P, Shore P. (2021) Position sensor for active magnetic bearing with commercial linear optical encoders. CIRP Annals - Manufacturing Technology, Volume 70, Issue 1, 2021, pp. 419-4220007-8506https://doi.org/10.1016/j.cirp.2021.04.092https://dspace.lib.cranfield.ac.uk/handle/1826/16947Active magnetic bearings are used in a number of applications but their disadvantage is the high asynchronous error due to sensor noise amplification. In this paper a new radial position sensor for active magnetic bearings (AMB) based on linear optical encoders is presented. A commercial encoder scanning head faces a round scale with concentric, coplanar lines on its face. Because such a scale is not readily available, it is made by high precision micro machining and different options are compared. In experiments a measurement noise of 3.5 nm at 10 kHz bandwidth is achieved. In addition, a magnetic bearing is built to demonstrate the sensor in closed-loop.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Magnetic bearingEncoderMicro machiningArticle