The Digital-Twin Modeling Method and Cross-Coupling Mechanism of Quartz Flexible Accelerometer

Quartz flexible accelerometers (QFAs) are widely applied in navigation systems. Although mechanical excitation is known to degrade the QFA performance and lower the positioning accuracy of the system, the mechanism underlying the dynamic performance deterioration remains obscure. Considering the etching process and assembly deviation, this article theoretically derives a pendulum cross-coupling mechanism and quantifies the transfer process of the structural error in the beams. The physical process of QFA is represented by a motion model, electrostatic and electromagnetic field models, and a signal transmission model. The QFA was analyzed through a digital-twin modeling approach incorporating finite element modeling and numerical analysis. The digital-twin model verified the error-transfer process of the beam structure and vibration experiments confirmed the specific effects of cross coupling. This article quantifies the dynamic accuracy degradation caused by interior errors in the QFA, providing guidance for optimizing the structure and assembly process of QFAs and promoting their environmental adaptability.