耦合结构对音叉式陀螺振动特性的影响

Influence of Coupled Mechanism on Vibration Characteristics of Tuning Fork Gyroscope

耦合结构对MEMS音叉式陀螺振动特性具有重要影响。针对一种典型结构的音叉式陀螺及其耦合结构,在分析其工作原理的基础上,建立了其驱动模态的振动模型。基于该模型,计算了在陀螺刚度不对称、驱动力幅值不对称及质量不对称3种情况下,该耦合结构对陀螺振动特性的影响。利用有限元仿真软件,对该耦合结构在3种情况下对陀螺振动特性的影响进行了仿真比较。计算与仿真结果表明,当驱动力频率恒定时,耦合结构的刚度对振动特性无影响;但是对于工作在固有频率点的音叉式陀螺,通过改变耦合结构尺寸,能够调整陀螺固有频率,进而对振动特性产生影响。根据结果,提出了音叉式陀螺耦合结构的设计准则。

Coupled Mechanism plays an important role in vibration characteristics of MEMS tuning fork gyroscope. A drive mode vibration model of a typical tuning fork gyroscope and its coupled mechanism was constructed based on its operating principle. On the basis of the vibration model, the influence on vibration characteristics by coupled mechanism was calculated in the situation of asymmetric stiffness, asymmetric driving force amplitude and asymmetric mass. Simulation and comparison was implemented in FEM software to research the influence. The results of calculation and simulation show that when the frequency of driving force is constant, the stiffness of coupled mechanism has no influence on vibration characteristics. But for the tuning fork gyroscope which works at the natural frequency, the dimension of coupled mechanism affects the natural frequency of gyroscope, and thus affects its vibration characteristics. According to the result, the design criterion of coupled mechanism in tuning fork gyroscope was proposed.