硅微陀螺正交误差校正方案优化

Optimization of quadrature error correction method for silicon MEMS gyroscopes

本文意在寻求双质量硅微机械陀螺仪正交校正最优方案。首先介绍了带有正交校正和检测力反馈梳齿的双质量硅微机械陀螺结构,量化分析了正交误差对输出信号的影响并进行了仿真,结果显示解调相角变化为±2°,200(°)/s的正交误差等效输入角速率可引起15(°)/s的输出信号变化。然后,对目前3种比较主流的硅微机械陀螺仪正交校正方法(电荷注入法(CIM)、正交力校正法(QFCM)和正交耦合刚度校正法(QCSCM))进行了实验研究,从理论上证明了这3种方法的可行性。对未加入正交校正环节的陀螺进行了实验,结果显示其左、右质量块输出的正交误差信号峰峰值分别为150mV和300mV。针对两质量块正交误差不等的实际问题提出了质量块单独校正的方案。采用CIM、QFCM和QCSCM对校正前零偏及其稳定性分别为-4.589(°)/s和378(°)/h的陀螺进行了实验校正,结果显示3种方法均可有效消除检测通道中正交信号,3种方法的零偏及零偏稳定性结果分别为-8.361(°)/s和423(°)/h,2.419(°)/s和82(°)/h,1.751(°)/s和25(°)/h,证明了正交耦合刚度校正法为3种方法中的最优方案。

This paper focuses on finding out a optimum quadrature error correction method for a dualmass Micro-electro-mechanical System（MEMS）gyroscope with quadrature error correction combsand sense feedback combs.The structure of the gyroscope was introduced,and influences of quadrature errors on the output signals were simulated and quantized.The results show that quadrature error equivalent angular rate is 200（°）/s and the demodulation phase error is less than 2°,which generates 15（°）/s variation of output signal.Three kinds of quadrature error correction methods used commonly in measuring this structure were investigated,and they are Charge Injecting Method（CIM）,Quadrature Force Correction Methods（QFCM）and Quadrature Coupling Stiffness Correction Method（QCSCM）.The feasibility of the three method was verified in theory.A gyroscope without quadrature error correction was tested,the results show that the quadrature signal peak-peak amplitudes from left and right mass preamplifiers are 150 mV and 300 mV respectively.Then,the correction method based on left mass and right mass independently was proposed.The the experiments based on CIM,QFCM and QCSCM were performed.The results show that the quadrature error signals are eliminated basically,their bias values and bias stabilities are-8.361（°）/s and 423（°）/h,2.419（°）/s and 82（°）/h,1.751（°）/s and 25（°）/h,respectively.According to the results,the QCSCM is verified to be the optimal method for quadrature error correction,and the theory analysis result is correct.