MEMS Gyro Compassing: Is Symmetry the Key?

• Published in: 2023 DGON Inertial Sensors and Systems (ISS) pp. 1 - 20
• Main Authors: Bange, S., Jackle, A., Konig, S., Loffelmann, U., Marx, M., Maurer, M., Meier-Meybrunn, S., Nessler, S., Pfeiffer, J., Rombach, S., Ruf, M.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 24.10.2023
• Subjects: Inertial sensors; Microelectromechanical systems; Micromechanical devices; Optical fibers; Temperature measurement; Temperature sensors; Vibrations
• ISSN: 2377-3480
• DOI: 10.1109/ISS58390.2023.10361927

Replacing expensive and bulky gyroscope technologies, e.g., based on fiber optics, with lower-cost and smaller microelectromechanical systems (MEMS) is a promising yet challenging approach for high-performance applications. In this paper, we present a comparison between asymmetric and symmetric MEMS gyroscopes that we have developed. The focus with respect to the application is on gyro compassing. The theoretical advantages and disadvantages of the two approaches are compared both qualitatively and quantitatively by means of theoretical considerations and with respect to the requirements of gyro compassing. A mature classical asymmetric tuning fork design and a symmetric quadruple mass design are presented and their parameters are compared to derive their influence on noise. Measurements show that the asymmetric sensors achieve a typical ARW \lt 5 \mathrm{m} {}^{\circ}/ \sqrt{\mathrm{h}} and repeatable rms bias model errors over temperature of approximately 0.5 °/h. The symmetric design achieves a typical ARW of about 20 \mathrm{m} {}^{\circ}/ \sqrt{\mathrm{h}} and repeatable rms bias model error of about 0.15 °/h. Based on the results, additional steps are outlined to improve performance even further.