Abstract

The most critical element of Hemispherical Resonator Gyroscope (HRG) is the high quality factor (Q-factor) mechanical resonator. This paper discusses the role of thermoelastic damping (TED) on effective Q-factor. Finite element method (FEM) is used to solve this highly coupled field problem involving vibration, solid mechanics, heat transfer and thermodynamics. The major contribution of this paper is the sensitivity analysis of the effect of material property, operating temperature and dimensions to arrive at macro scale resonator configuration. Hybrid hemispherical-cylindrical configuration is proposed by studying the performance parameters such as effective mass and angular gain.The uniqueness of the present work is the sensitivity study of ultra thin film coating (volume fraction of 0.01%), coating variations and different coating configurations. The coating can reduce the Q-factor by a few orders compared to uncoated shell. It hs been found that coating material selection and coating configuration are very important factors. Another significance of the present work is the realization and detailed characterization of the hybrid fused silica resonator. Thin film gold coating is done on the 3D surfaces of the realized precision resonator. Detailed coating characterization is carried out using sophisticated instruments. Very fine balancing to the order of a few mHz is achieved after coating. Q-factor measurement of the coated resonator is carried out using LDV and achieved a few millions in the final functional hybrid resonator.

中文翻译：

---

基于热弹性阻尼的高品质因数功能性混合陀螺谐振器的设计、灵敏度研究和演示

摘要

半球谐振陀螺仪 (HRG) 最关键的元素是高品质因数 ( Q- factor ) 机械谐振器。本文讨论了热弹性阻尼 (TED) 对有效Q-因素。有限元方法 (FEM) 用于解决这个涉及振动、固体力学、传热和热力学的高度耦合场问题。本文的主要贡献是对材料特性、工作温度和尺寸的影响进行灵敏度分析，以达到宏观尺度的谐振器配置。通过研究有效质量和角增益等性能参数，提出了混合半球-圆柱配置。本工作的独特之处在于超薄膜涂层（体积分数为 0.01%）、涂层变化和不同涂层配置的敏感性研究。涂层可以降低Q- 与无涂层外壳相比，系数降低了几个数量级。已经发现涂层材料的选择和涂层配置是非常重要的因素。目前工作的另一个重要意义是混合熔融石英谐振器的实现和详细表征。在实现的精密谐振器的 3D 表面上完成薄膜镀金。使用精密仪器进行详细的涂层表征。涂层后实现了几 mHz 量级的非常精细的平衡。涂层谐振器的Q 因数测量是使用 LDV 进行的，并在最终的功能混合谐振器中达到了数百万。