驱动微梁梁宽误差对微陀螺性能的影响

Effect on drive micro beam width error on performance of micro gyroscope

建立了3类微梁加工误差的有限元分析模型,采用有限元分析的方法研究了3种不同类型的梁宽误差对微陀螺固有频率、模态和检测信号的影响。研究发现:驱动微梁尺寸的加工误差不仅会影响到驱动模态的固有频率,同时也会对检测模态的固有频率产生影响;同一对角线上微梁尺寸相同的加工误差会引起微陀螺驱动模态及检测模态的耦合,并给出了模态耦合的特征,且耦合程度随梁宽误差的加大而增加;同一侧梁宽相同及只一根微梁梁宽存在加工误差时的模态耦合可以忽略;模态耦合会对微陀螺的检测信号产生严重的干扰,干扰程度与模态耦合程度正相关。

Finite element analysis model for three kinds for micro-beam machining error is established. The finite element analysis method is used to study influence of three different types of beam width error on natural frequency, mode and detecting signal of micro gyros. It is found that the processing error of driving micro-beam size not only affect natural frequency of drive mode, but also affect natural frequency of detecting mode. The machining error of the same size micro-beam on the same diagonal will cause coupling of drive mode and detecting mode and the characteristic of modal coupling is given, and the coupling degree increases with increase of the beam width error. The modal coupling can be neglected when the same side beam width is the same and only one micro beam width exists processing error. The modal coupling will cause serious interference to detecting signal of micro gyros, and the degree of interference is positively correlated with the modal coupling degree.