石英振梁加速度计静态输入输出特性

Static input-output characteristics for quartz vibrating beam accelerometers

通过平衡方程建立了一种石英振梁加速度计敏感元件的静力学模型,分别利用梁弯曲振动微分方程和有限元分析方法获得了敏感元件的输入加速度与输出频率之间的精确关系,从而从理论上获得了敏感元件的静态输入输出特性。通过离心试验对所设计的加速度计进行了标定,并与理论计算结果进行比对,最终认为理论计算能够准确的反映出石英振梁加速度计的静态输入输出特性。同时,该计算方法可以为其他包含振梁的传感器的设计提供依据。最后,提出了实测结果与理论计算存在偏差的原因:标度因数的偏差来源于振梁厚度的加工误差,非线性度的偏差来源于装配角度偏差以及外界温度变化引起的频率漂移等因素。

The static model of a quartz vibrating beam accelerometer’s sensing element was established based on equilibrium equations. The precise relations between the input acceleration and the output frequency of the sensing element were deduced based on flexural vibration differential equation and finite element analysis. Then the static input-output characteristics of the sensing element were obtained in theory. Furthermore, the static input-output characteristics of the accelerometer were calibrated via centrifugal test. The test results were compared with the theoretical calculation results. In conclusion, the theoretical prediction can precisely reveal the static input-output characteristics of the quartz vibrating beam accelerometer. The analysis method of this paper can provide valuable references for the design of other sensors with the vibrating beam. In the end, it is pointed that there are differences between the results obtained from the centrifugal test and the calculation, in which the scale factor deviation is caused by the micro-machining error in the beam thickness and the deviation of the nonlinearity is ascribed to assembly errors, frequency shift.