微机电陀螺耦合刚度的辨识

针对微机电陀螺耦合刚度的辨识,提出了以驱动轴、检测轴、驱动-转动耦合和驱动-检测耦合频率响应特性为基础的耦合刚度辨识方法。设计了一种驱动轴和检测轴双向位移解耦的双质量线振动微机电陀螺,基于经过简化的梁的刚度特性建立了微陀螺平面运动动力学方程,导出了结构在存在耦合刚度情况下驱动轴、检测轴、驱动-转动耦合和驱动-检测耦合的传递函数。根据耦合传递函数把刚度耦合产生的根源定位到特定的几组梁之间的刚度误差。通过驱动-转动耦合与驱动轴幅频特性之比辨识出驱动-转动耦合刚度系数,通过驱动-检测耦合与检测轴幅频特性之比辨识出转动-检测耦合刚度系数。实验测试了设计加工的微陀螺的频率响应特性,利用提出的耦合刚度辨识方法得到陀螺的驱动-转动和转动-检测耦合刚度系数分别为0.14N和0.054 33N。得到的耦合刚度的辨识结果可为微陀螺梁刚度的激光修调提供参数依据。

Identification of coupling stiffness for MEMS gyroscope

For identification of the coupling stiffness of MEMS (Micro-electro-mechanical System) gyroscopes, a identification method was proposed based on the frequency response characteristics of the drive-axis, sense axis, drive-to-rotation coupling and rotation-to-sense coupling. A dual-mass linear vibrating MEMS gyroscope with decoupled drive-to-sense and sense-to-drive displacement was designed. Based on simplified stiffness characteristics of the beams, the dynamic planar movement equations of the gyroscope were established and the drive-axis, sense-axis, drive-to-rotation and drive-to-sense transfer functions were derived. According to the coupling model, the sources of stiffness coupling were attributed to the stiffness error of specific beams. The drive-to-rotation coupling stiffness could be identified by the ratio of drive-to-rotation coupling to drive-axis frequency responses, and rotation-to-sense coupling stiffness could be identified by the ratio of drive-to-sense to sense-axis frequency responses. The frequency responses of the gyroscope were investigated by the proposed coupling stiffness identification method, and results show that coupling stiffness coefficients by drive-to-rotation and rotation-to-sense for the tested gyroscope are 0.14 N and 0.054 33 N, respectively. It concludes that the identification results provide references for laser trimming of the beams for gyroscopes.