Active Amplitude and Frequency Control for Frequency Modulated Gyroscopes: Components of Enabling High Stability Frequency Modulated Inertial Sensors
Abstract
Frequency modulated (FM) gyroscopes have been reported to either have excellent short-term and long-term stability depending on the implementation. This trade-off between short-term stability and long-term stability may be related to design choices with sub-systems for amplitude and frequency control. This work is focused on empirically studying the impact of amplitude and frequency control. Prior to results, background information on amplitude and frequency control are presented. The results section is composed to two sections. The first section is on the impact of the inclusion of integral control to maintain a given amplitude. It is found that adding integral control both improves amplitude matching, as quantified by scale factor, and long-term zero rate output stability. The second section is on the addition of frequency control. With a combination of active amplitude and frequency control, non-stationary noise processes are removed from the rate estimate. While the addition of frequency control does not improve the raw zero rate bias instability, during time periods of low temperature variation, the output can be easily compensated for by using the control voltages to maintain constant frequency.. Once compensated, the output can be further filtered using autoregressive methods to remove correlated noise processes. As an added benefit, this filtering helps to reduce angle random walk (ARW). This filtered output demonstrates a bias instability of 0.2 deg/hr at 1,000 sec. With future plans to both improve the resolution of the frequency detector and add active temperature control, it is expected that navigation-grade performance should be possible with the current sub-2 mm by 2 mm dies.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2022
- Accession Number
- AD1158515
Entities
People
- Andrew Sabater
- Eric Bozeman
Organizations
- Naval Information Warfare Center Pacific