| 研究開始時の研究の概要 |
We would like to design a highly symmetric resonator for frequency modulated (FM) gyroscope, which can further increase the performance of MEMS gyroscope and can be applied to the automotive applications.
The novel gyroscope resonator will be design and fabricated. The device will be evaluated in the vacuum chamber firstly and the electrostatic tuning method to achieve frequency and Q-factor matching will be investigated.
Furthermore, this resonator will be vacuum packaged and applied to the FM system. The performance of this highly symmetric resonator will be characterized in the FM system.
|
| 研究実績の概要 |
This research introduces a novel triple mass resonator (TMR) and a two-axis symmetric resonator with multiple proof masses for improving stiffness sensitivity and tuning capability of MEMS res- onators. The frequencies of the anti-phase (ωanti) and in-phase (ωin) modes have a strong dependency on the suspension and inner stiffness, respectively. Therefore the frequency difference can be electro- statically tuned by either suspension stiffness nor inner stiffness. The amplitude ratio can be adjusted largely by decreasing the inner stiffness, which brings a significant change in Q-factor related to anchor loss or squeeze film damping, while a negligible shift in frequency ωanti. When the frequency ωanti is tuned by decreasing suspension stiffness of two main proof masses, only a slight change in the mode shape, i.e. the amplitude ratio, is observed causing a minor adjustment to Q-factor. Therefore the frequency ωanti and Q-factor can be tuned independently under a little mutual influence.
A two-axis symmetric tuning fork resonator based on TMR technique is applied for QFM/RIG. Two dynamically equivalent proof masses provide a balance dynamic system and four extra-small masses is implemented in between them, which could tune the Q-factor of two anti-phase modes independently with small effect on the frequency. Frequency is mainly affected by suspension stiffness and Q-factor is strongly dependent on the squeeze film damping through the mode coupling between two balanced masses and small masses.
|
