驱动微梁形状对微陀螺仪耦合误差的影响分析

为研究微陀螺驱动微梁在加工误差下的微梁形状变化对正交耦合误差、模态耦合以及检测信号的影响,建立了驱动微梁在对角线梁宽误差下的有限元分析模型,采用有限元仿真分析和解析计算相结合的方法研究了U型梁一端梁长的变化对微陀螺正交耦合误差、模态耦合以及检测信号的影响.研究发现,当U型梁一端的梁长为另一端长度的二分之一左右时该类加工误差会引发非常严重的正交耦合误差和模态耦合现象,并对检测信号产生极大影响;当U型梁退化为直梁或者为等长梁的时候,对检测信号的干扰很小、正交耦合误差为零、模态耦合程度最小,而且两者的变化规律呈现正相关.适当地加大单自由度微陀螺驱动模态和检测模态的频率差不仅可增加微陀螺的带宽还可减小耦合的影响.

Analysis of the Influence of Driving Micro Beam Shape on MEMS Gyroscope Coupling Error

Under the machining deviation,in order to study the effect of the microgyroscope drivingmicrobeam Shape Variation on orthogonal coupling Error,modal coupling and detection Signal. The finite element analysis model of the driving microbeam under the diagonal beam width error is established,the influence of the variation of the length of one end of U-beam on the orthogonal coupling error,modal coupling and detection signal of micro-gyroscope is provided by combining the method of elemental simulation and analytic calculation. It is found that when the beam length of one end of U-beam is about one half of the length of the other end,this kind of machining deviation will cause very serious orthogonal coupling error and modal coupling phenomenon,and it have great influence on the de-tection signal. When the U-beam is degraded into a straight beam or an equal length beam,the interference of the detection signal is very small,the orthogonal coupling error is zero,the modal coupling degree is the smallest,and the variation rule of the two is positively correlated. Increasing the frequency spacing between the driving mode and detecting mode of the single degree of freedom microgyroscope. Not only adding the bandwidth of microgyroscope, but also reducing the influence of coupling.