Design and vibration sensitivity of a MEMS tuning fork gyroscope with anchored coupling mechanism

Abstract

In this paper, a novel MEMS tuning fork gyroscope with anchored coupling mechanism is designed to analyze the mode ordering and vibration sensitivity. The proposed TFG prioritizes anti-phase drive-mode by using a levered mechanism while the sense-mode is prioritized utilizing an anchored coupling ring spring linked by four linear beams, which eliminates the lower frequency parasitic mode and provides true mechanical suppression of external vibration. In order to make a contrast with the proposed novel anchored coupling TFG, a conventional one with a direct coupling ring spring between two tines is also designed. The simulated frequencies of the in-phase and anti-phase in the sense mode are 4,006.8 and 4,463.5 Hz, respectively. Meanwhile, the in-phase frequency of the anchored coupling TFG is 5,958.4 Hz, improving by 48.7 %, and the anti-phase frequency is increased a little. Additionally, we carry out the FEM simulations on the vibration sensitivity induced by the stiffness imbalance for the two types of TFGs. Our results demonstrate that the vibration output is reduced by 74.8 and 88.1 % in the anti-phase mode and in-phase mode, respectively. Therefore, the novel anchored coupling TFG can provide improved mode ordering and substantially suppress the vibration output without compromising the scale factor.