提高载体驱动硅微陀螺灵敏度的方法

Improving the sensitivity of carrier-driven Si micromechanical gyro based on duty ratio of pulse signal

载体驱动硅微陀螺是一种利用体微工艺制备的新型电容式振动MEMS陀螺,它安装于旋转飞行器上,利用载体的自旋作为驱动。当载体发生横向转动时,敏感质量受到周期性科氏力的作用,产生振动,从而敏感输入角速度。针对该种MEMS陀螺,首先介绍了陀螺的工作原理和电容式检测结构,然后详细分析了差分电容与敏感质量偏转角之间的关系,最后提出了一种通过调节电容拾取电路的脉冲信号的占空比,来提高陀螺灵敏度的方法。实验测试结果表明,当占空比由50%调整到75%时,相应输出电压峰峰值可由10.7 V提高到13.1 V,提高幅度达22.43%。理论分析和实验结果均表明,该方法可简便有效地提高陀螺灵敏度,具有实际应用价值。

The carrier-driven Si micromechanical gyro is a new type of capacitive vibratory MEMS gyro, which is fabricated by using bulk micromechanical process.It is mounted on a rotating aircraft and utilizes the carrier＇s spinning as the driving force.When the carrier is subjected to a transverse rotation, a periodic Coriolis force will be produced, and the input angular velocity will be sensed.In view of this type of MEMS gyro, its working mechanism and the capacitive detective structure were introduced, and the relation between the differential capacitance and the deflection angle of sensing mass was analyzed.Finally, a method for adjusting the duty ratio of the pulse signal of capacitance pickup circuit was put forward to improve the sensitivity of the MEMS gyro.Experimental tests show that the peak-to-peak voltages of gyro output is increased from 10.7 V to 13.1 V, which is increased by 22.43%, when the duty ratio is adjusted from 50% to 75%.Theoretical analysis and experimental results both show that the method can effectively improve the gyro sensitivity and has practical application value.