MEMS加速度計の精度向上に向けた新たな設計手法(New Study Reveals Dual-Mode Design Boosts MEMS Accelerometer Accuracy)

2025-11-11 中国科学院(CAS)

中国科学院航空情報研究院の鄒旭東教授らは、MEMS共振加速度計の主要課題である温度ドリフト測定デッドゾーンを同時に解決するため、2本の差動ビームの共振周波数を意図的に分離するデュアルモード動作方式を提案した。1本を一次共振モード、もう1本を二次共振モードで駆動することで、温度補償性能が向上し、モード局在化によるデッドゾーン発生を抑制できることを実証。実験では温度ドリフトが従来の約342 mgから1.19 mgへと280倍以上改善した。また、Allan偏差・PSD解析から低周波ノイズが大きく低減し、長期安定性も向上。周波数の重なりを排除することでデッドゾーン問題も完全に解消された。この手法は低コストで高精度化を実現でき、慣性航法や振動監視などMEMS加速度計の応用に有用とされる。

<関連情報>

デュアルモード動作方式を用いた差動MEMS共振加速度計における温度ドリフト抑制と測定デッドゾーンの排除 Temperature drift suppression and measurement dead zone elimination in differential MEMS resonant accelerometers using dual-mode operating method

Bingchen Zhu,Zheng Wang,Liangbo Ma,Zhaoyang Zhai,Kunfeng Wang,Wuhao Yang,Xiaorui Bie & Xudong Zou
Microsystems Nanoengineering  Published:28 October 2025
DOI:https://doi.org/10.1038/s41378-025-01022-1

MEMS加速度計の精度向上に向けた新たな設計手法(New Study Reveals Dual-Mode Design Boosts MEMS Accelerometer Accuracy)

Abstract

This paper proposes a differential mode measurement and control system (DMCS) for differential MEMS resonant accelerometer (DMRA), which operates the differential resonators of the DMRA at different vibration modes. Unlike traditional DMRA, the first resonator of the differential resonator operates in the first-order mode (R1M1), and the second resonator operates in the second-order mode (R2M2). Within the measurement range of DMRA, the frequencies of the two resonators will not cross, so there will be no mutual interference. This ensures the structural symmetry of the DMRA while avoiding the measurement dead zone phenomenon caused by the coupling of the differential vibration beam at similar resonant frequencies. The structural symmetry of the differential resonator ensures good temperature consistency of the differential vibration beam, and the consistency of the temperature frequency coefficient matches well, which enables the differential resonator to strongly suppress the temperature-induced common-mode effects. During the temperature cycling process between -20 °C and 80 °C, the equivalent acceleration drift of R1M1 and R2M2 were 341.6 mg and 414.6 mg, respectively. After using the differential temperature compensation algorithm, the equivalent acceleration drift was reduced to 1.19 mg. The minimum Allan variance measured statically at room temperature decreased from 1.42 μg@0.85 s for R1M1 and 1.52 μg@0.85 s for R2M2 to 0.23 μg@7.15 s, indicating a significant improvement in the long-term stability of DMRA. In addition, the differential measuring method also eliminated common mode ambient noise in low frequency range, ultimately achieving a noise level of 220 ng/√Hz@(0.2–0.8 Hz) for a prototype device with a measurement range exceeding ±5 g.

0110情報・精密機器
ad
ad
Follow
ad
タイトルとURLをコピーしました