栅结构微机械陀螺运动特性的研究

STUDY ON DYNAMIC CHARACTERISTIC OF A NOVEL SILICON MICROMACHINED GYROSCOPE

对一种新型微机械振动陀螺原型的运动特性进行了理论分析。采用差分电容信号调制解调方法测量了微机械陀螺驱动和检测模态的幅频特性。理论计算和实验结果表明 ,在大气状态下 ,该微机械陀螺驱动模态和检测模态的品质因子具有相近数值 ,在 10 0左右。测量了驱动模态静电激励驱动下 ,微机械陀螺检测模态的幅频特性 ,实验结果表明 ,在无角速度输入的情况下 ,微机械陀螺在驱动模态和检测模态的谐振频率处发生谐振。

A novel silicon micromachined gyroscope were presented. The device structure which we called 'fence gyro' consists of a proof mass with bars linked up to substrate by suspend springs. The dynamic characteristic of the prototype of the novel micromachined gyroscope was analyzed. By the means of differential capacitance signal modulated and demodulated, the frequency behaviour of the drive and detection modes of micromachined gyroscope were measured. As the proof mass used as the movable electrodes is parallel to the plane of fixed driving and sensing electrodes, there is only slide film damping in the driving and sensing mode. The calculated results shown that the gyroscope has the almost same Q-factor of the detection mode and drive mode at atmospheric pressure, which is in order of 100. Under the electrostatic excitation in the drive mode, the frequency behaviour of the detection mode was measured. The experiment result shows that the drive and sense mode resonant frequencies are 460 Hz and 549.6 Hz respectively, and the Q factor of the drive and sense are 102.5 and 106.5 respectively at atmospheric pressure. The experiment result also shows that the micromachined gyroscope exhibits resonance at the resonance frequency of the drive and detection mode without inputting angular rate as mechanical couple.