硅微静电悬浮加速度计实验研究

Experimental study of Si micromachined electrostatically suspended accelerometer

硅微静电加速度计将静电悬浮技术与微机械加工工艺相结合,在空间微重力环境下通过降低量程可实现极高的分辨率。设计了一种玻璃—硅—玻璃三明治结构、平行六面体状检测质量、体硅加工工艺、低量程的三轴硅微静电加速度计,分析了加速度计的力平衡回路特性。采用基于DSP的数字控制器,实现了检测质量的六自由度稳定悬浮。在大气环境下测试了静电加速度计的性能。测试结果表明:加速度计x轴的带宽为88.1 Hz,量程为0.220 g n;y轴的带宽为118.2 Hz,量程为0.313 g n;z轴的带宽为10.7 Hz,量程为3.53 g n。

Si micromachined electrostatically suspended accelerometers which combines electrostatic suspension and micromachined fabrication technology,can realize extremely high resolution with ultra-low acceleration range for miro-grivity space applications.A low range,tri-axis micromachined electrostatically suspended accelerometer is designed with a free parallelepiped proof mass,and realized in a glass-silicon-glass sandwich structure by bulk silicon micromachining technology,and property of the force balance loop of accelerometer is analyzed.A DSP- based digital controller is realized to achieve stable levitation of the proof mass electrostatically in six degrees of freedom.The experimental results of the accelerometer operated in the atmospheric environment show that the closed-loop suspension bandwidth and measuring ranges are 88.1 Hz,0.220 g n in the x axis; 118.2 Hz,0.313 g n in the y axis; and 10.7 Hz,3.53 g n in the z axis,respectively.