Si MEMS陀螺仪的正交耦合补偿技术

Quadrature Coupling Compensation Technology in Si MEMS Gyroscopes

为了减小正交耦合误差对硅微电子机械系统(MEMS)陀螺仪性能的影响,提高陀螺仪零偏精度,对MEMS陀螺仪正交耦合补偿技术进行研究。建立MEMS陀螺仪动力学模型,分析正交耦合产生的原因,介绍了各类正交耦合补偿机理。设计了一款可实现静电刚度补偿的MEMS陀螺仪,并利用绝缘体上硅(SOI)工艺进行制备。利用现场可编程门阵列(FPGA)实现陀螺仪静电刚度正交耦合闭环补偿,并对陀螺仪进行了测试。测试结果表明,MEMS陀螺仪经过静电刚度正交耦合补偿后,角度随机游走由0.023°/√h变为0.06°/√h,零偏不稳定性由4.58°/h提升为0.27°/h,零偏稳定性由71.86°/h提升至1.29°/h(10 s平均处理),全温范围内零偏变化量由0.648°/s降低为0.01°/s。实验结果显示,经过正交耦合静电刚度闭环补偿,陀螺仪零偏性能明显提升。

To reduce the influence of the quadrature coupling error on the performance of the silicon micro-electromechanical system(MEMS)gyroscope and improve the zero bias precision of the gyroscope,the quadrature coupling compensation technology of the MEMS gyroscope was studied.The kinematic model of the MEMS gyroscope was built,the cause of the quadrature coupling was analyzed,and the mechanisms of the quadrature coupling compensation were introduced.A MEMS gyroscope was designed to realize the electrostatic stiffness compensation,and the gyroscope was fabricated with the silicon-on-insulator(SOI)process.The electrostatic stiffness quadrature coupling closed-loop compensation of the gyroscope was realized with the field programmable gata array(FPGA),and the test of the gyroscope was carried out.The test results show that after the electrostatic stiffness quadrature coupling compensation of the MEMS gyroscope,the angle random walk changes from 0.023°/√h to 0.06°/√h,the zero bias instability increases from 4.58°/h to 0.27°/h,the zero bias stability increases from 71.86°/h to 1.29°/h(10 s average processing),and the variation of zero bias in the full temperature range decreases from 0.648°/s to 0.01°/s.The experimental results show that the zero bias performance of the gyroscope is significantly improved by the quadrature coupling electrostatic stiffness closed-loop compensation.