扭摆式高g值微机械加速度计的设计优化与冲击校准  

Optimization design and shock calibration of pendulous high-g micro-machined accelerometer

作　　者：陶永康[1] 刘云峰[1] 朱科引 董景新[1] 

机构地区：[1]清华大学精密仪器系,北京100084

出　　处：《振动与冲击》2015年第1期53-57,共5页Journal of Vibration and Shock

基　　金：国家十二五预研基金资助项目(51309020301)

摘　　要：设计实现了一种扭摆式高g值微机械加速度计。微结构采用十字形扭梁减小横向效应,摆片两侧使用梳齿结构作为止档和阻尼器,6个敏感单元并联的方式提高基础电容量。有限元仿真得到表头谐振频率约为56 k Hz,前两阶模态分离比大于4,高过载能力10万g,微结构灵敏度为8.94E-6p F/g,基于玻璃-硅(Silicon On Glass,SOG)工艺流片后单侧基础电容约为3.6 p F。分析了环形二极管电容检测电路的检测带宽问题,并设计了高g值加速度计的检测电路。搭建了霍普金森杆实验系统进行高g值的冲击校准,2万g范围内非线性度2%,5 V供电下标度因数约为24.5μV/g。A kind of pendulous high-g micro-machined accelerometer was designed.Cruciform torsion beam was applied to reduce cross-axis sensitivity,and comb structure was used as stopper and damper.The micro-structure parallels 6 sensing units to improve initial capacitance.Based on finite element analysis,the micro-structure’s natural frequency is about 56 kHz with modal separation ratio more than 4.It can resist 1E5 g shock acceleration and the micro-structure’s sensitivity is 8.94E-6pF /g.The accelerometer’s fabricated by silicon on glass （SOG）technology,and its single-side initial capacitance is about 3.6pF.The measurement bandwidth of ring diode capacitance detection circuit was analyzed and a high g accelerometer’s detection circuit was designed.Calibrated by Hopkinson bar,the accelerometer’s nonlinearity is 2% of 2E4 g range,and the scale factor is about 24.5μV /g with 5V supply.

关 键 词：高g值微机械加速度计 扭摆式加速度计 检测读出电路 霍普金森杆 冲击校准 

分 类 号：TH7[机械工程—仪器科学与技术] U666.1[机械工程—精密仪器及机械]