摘要
建立了真空封装陀螺的无激励欠阻尼二阶系统模型,用于测量真空封装硅微陀螺的品质因数。对该模型进行理论推导,提出了一种时延常数测试方法。该方法首先利用锁相环路,驱动陀螺实现闭环谐振,获得较大的初始振幅。然后关断激励信号,通过放大电路和解调电路,记录硅微陀螺振荡幅值的衰减过程;用计算机通过Matlab GUI实时采集并拟合振幅衰减曲线,获得时间常数。最后,通过时间常数解算获得真空封装硅微陀螺的品质因数。对真空封装硅微陀螺品质因数的实验测试结果表明:该方法实测数据与理论分析模型的拟合度为99.999%,测试重复性为4.03%,优于传统的扫频测试法的重复性。对比时延常数法与锁相放大器扫频测试法的测试数据显示:时延常数法具有更高的测量精度和更高的测试效率。该方法可以推广到其它高真空封装MEMS器件的品质因数测量。
A under-damping second-order system model without excitation was proposed to measure the quality factor（Q factor） for a vacuum packaged microgyroseope. The model was analyzed theoreti- cally and a time decay constant method was presented. Firstly, an initial displacement of the seismic mass was obtained by exciting the microgyroscope to implement a closed loop resonance with a Phase Locked Loop （PLL）. By releasing the excitation signal, the vibration amplitude decay curve was then acquired through demodulating the vibrating displacement signal and was transferred to a computer by a Field Programming Gate Array（FPGA） hardware and Matlab GUI software simultaneously. Final- ly, the Q factor of the vacuum packaged microgyroscope was calculated by exponentially fitting the envelope of decay curve. The experimental results show that the R-square value of the fitted curve reaches up to 99. 999% as compared to the measured data and the repeatability of the tested Q factor is 4.03%, much better than that of the frequency sweeping method. Comparing the measurement data of decay constant method and frequency sweeping method, the former shows better measurement accuracy and higher efficiency. The meth- od is also suitable for the measurements of microsensors with high Q factors.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2014年第10期2708-2714,共7页
Optics and Precision Engineering
基金
国家863高技术研究发展计划资助项目(No.2011AA110102)
国家国际科技合作专项资助项目(No.2011DFA72370)
关键词
硅微陀螺
真空封装
品质因数
标定
时延常数法
扫频法
microgyroseope
vacuum packaging
quality factor
calibration
decay constant method
frequency sweeping method
