基于虚拟科氏力相位特性的硅MEMS陀螺自动模态匹配及闭环检测

Automatic Mode-matching and Closed Loop Detection of Silicon MEMS Gyroscope Based on Virtual Coriolis Force Phase Characteristics

介绍了一种基于虚拟科氏力相位特性的自动模态匹配方法,该方法能提高开环检测时陀螺的标度因子、降低其零偏不稳定性。同时,为了增大模态匹配时的可检测输入角速度范围,采用力平衡反馈闭环,将科氏输出位移控制在一个幅度较小且稳定的振动状态。通过Simulink模型进行仿真,并在基于FPGA的数字控制电路中对本课题组的十六边型盘式谐振陀螺(cobweb-like DRG)进行实验。实验结果表明,使用该方法实现模态匹配后,开环检测时,陀螺的标度因子和零偏不稳定性分别从未匹配状态下的13 mV/[(°)·s]^-1、13.5°/h提高到了158 mV/[(°)·s]^-1、1.1°/h;自动模态匹配与闭环同时工作时,标度因子为76 mV/[(°)·s]^-1,零偏不稳定性为2.3°/h,可检测输入角速度范围为±31°/s。

An automatic mode-matching method was introduced based on phase characteristic of a virtual Coriolis force that can improve the scale factor and reduce the bias instability of open-loop gyroscope.Moreover,a force balanced feedback closed loop was developed to control the Coriolis output displacement to a small and stable vibration state to increase the full scale range.The method was simulated using a Simulink modal and verified by a FPGA-based digital control circuit on a cobweb-like disk resonator gyroscope(cobweb-like DRG).The experimental results show that the scale factor and zero-bias instability of the auto-mode-matched open loop gyroscope are improved to 158 mV/(°·s^-1)and 1.1°/h from 13 mV/(°·s^-1)and 13.5°/h for an unmatched mode,while the scale factor of 76 mV/(°·s^-1),the zero-bias instability of 2.3°/h,and the full scale range of±31°/s are achieved for the auto-mode-matched gyroscope under close-loop condition,respectively.