Nonlinearity Reduction in Disk Resonator Gyroscopes Based on the Vibration Amplification Effect

Abstract

This article reports a novel method to reduce the electrostatic and capacitive nonlinearities in a disk resonator gyroscope (DRG) and to further improve its ultimate oscillation amplitude for performances improvement. The DRG consists of multiple rings, in the working mode, the outer rings always have larger deformation than the inner rings, which is called the vibration amplification effect (VAE). Based on this effect, we propose a method to reduce the nonlinearity in a DRG by optimizing the electrode arrangement, that is, by using the inner electrodes for driving and the outer electrodes for sensing. To verify this method, a DRG with eight layers of driving electrodes was designed and fabricated. The influence of the electrode positions on the nonlinearity of the DRG was theoretically analyzed and experimentally tested. The results show that by using the nonlinearity reduction method, the nonlinearity of the DRG can be reduced and the ultimate oscillation amplitude can be increased to 49% of the capacitive gap, which is much larger than the oscillation amplitude of traditional DRGs. Meanwhile, the sensitivity of the DRG can be improved by 100% and the angle random walk and bias instability can be reduced by 53% and 63%, respectively.