相位误差对MEMS陀螺检测的影响分析及校正

为提升MEMS陀螺的整体检测性能,对解调参考信号的相位误差对MEMS陀螺检测的影响进行了分析,提出了基于矢量内积鉴相器的相位校正方法.首先从原理上分析了相位误差对解调结果的影响,然后建立了开环解调、静电力反馈正交误差消除加开环解调、静电力反馈正交误差消除加闭环解调3种典型MEMS陀螺检测电路的仿真模型,对解调参考信号存在相位误差的情况进行了仿真。仿真结果表明:不同解调方式中,相位误差对角速度和正交误差的解调影响基本一致,对陀螺的动态范围影响各不相同.同等输入条件下,解调参考信号的相位误差越大,角速度和正交误差的解调结果与真实值的偏差就越大,有必要进行相位校正以消除其影响。 在此基础上,首次将矢量内积鉴相法引入了MEMS陀螺检测电路中,提出了一种可以适用于3种情况的相位校正方法,并进行了仿真。仿真显示,该方法可以消除相位误差,校正正交误差系数和角速度解调误差,提升静电力反馈正交误差消除加开环解调电路的动态范围,且不会影响MEMS陀螺的启动时间,具备良好的通用性。

Impact analysis and correction of phase error on MEMS gyroscope detection

To improve the overall detection performance of MEMS gyroscope, the impact of phase error in demodulated reference signal on the detection of MEMS gyroscope was analyzed, and a phase correction method based on vector inner product phase detector was proposed. Firstly, the impact of phase error on demodulation results was theoretically analyzed. Then, the simulation models of three typical MEMS gyroscope detection circuits were established, including open-loop demodulation, electrostatic feedback quadrature error cancellation plus open-loop demodulation, and electrostatic feedback quadrature error cancellation plus closed-loop demodulation, and simulation of phase error in demodulated reference signal was carried out. Results show that among the three demodulation methods, the impacts of phase error on angular velocity and quadrature error were basically the same, while those on the dynamic range of gyroscope were different. Under the same input conditions, the larger the phase error was, the more the demodulated angular velocity and quadrature error were deviated from the real value, so it is necessary to carry out phase correction to eliminate such influence. On this basis, the vector inner product phase detection method was introduced into the MEMS gyroscope detection circuit, and a general phase correction method which can be applied in three cases was proposed and simulated. Simulation results indicate that this method can eliminate phase error, calibrate quadrature error coefficient and angular velocity demodulation error, and improve the dynamic range of electrostatic feedback quadrature error cancellation plus open-loop demodulation circuit without affecting the start-up time of MEMS gyroscope, which has good versatility.