硅微陀螺仪闭环正交校正研究

Research on Closed-Loop Quadrature Correction of Silicon Micromachined Gyroscope

针对硅微陀螺仪中正交误差的来源进行了分析,设计了一种基于正交校正电极的闭环控制回路。该电路通过正交校正电极产生静电耦合刚度,以此来抵消结构耦合刚度,从而抑制正交误差。给出了设计方案的原理框图,利用Simulink对整个控制回路进行仿真,仿真结果表明该方案能够较好地抑制正交误差。对加入正交校正前后的硅微陀螺仪样机进行了测试,实验结果表明加入闭环正交校正后,陀螺仪样机的正交误差信号已基本消除,零偏稳定性较校正前提高了一倍以上。

This paper analyzed the quadrature error of mems silicon gyroscope, based on which a closed-loop circuit for error correction was designed. Quadrature error, caused by the coupled structural stiffness between the operation modes,was corrected and suppressed by the coupled electrostatic stiffness generated by the quadrature error correction electrodes. Schematic of the correction circuit was designed and simulated using Simulink, results of which showed that the error was effectively suppressed. Besides, the design was also verified by the experiments and tests on the gyroscope prototype. The quadrature error has been basically eliminated after the quadrature correction. The experimental work shows bias stability is improved by more than 100% after the quadrature correction.