Vibration measurement without the Heydemann correction

• Main Authors: Wataru Kokuyama, Tomofumi Shimoda, Hideaki Nozato
• Format: Article
• Language: English
• Published: Elsevier 2021-12-01
• Series: Measurement: Sensors
• Subjects: Vibration measurement; Cyclic error; Spectral analysis; Digital filter
• Online Access: http://www.sciencedirect.com/science/article/pii/S2665917421000994

We propose a novel signal-processing technique to avoid cyclic errors in laser interferometers instead of an elliptical fitting, known as the Heydemann correction. It is based on a simple superposition of background motions to average out the effect of cyclic errors. With a simulation, we show that a single-frequency vibration can be extracted by applying filtering and fitting to the displacement data with an adding linear drift. We also experimentally show that the technique reduces the measured dispersion of the vibration amplitude. It offers a simple and economic interferometer for the single-frequency vibration measurement in primary vibration calibration systems.