一种微机械谐振式加速度计的自激驱动控制  

Resonant Accelerometer Based on Electrostatic Stiffness and its Closed-loop Control Method

作　　者：刘恒[1] 孟瑞丽[1] 

机构地区：[1]南京信息工程大学电子与信息工程学院,江苏南京210044

出　　处：《仪表技术与传感器》2012年第4期107-110,共4页Instrument Technique and Sensor

基　　金：中国工程物理研究院科学技术发展基金(2009B0403044)

摘　　要：为了研制谐振微机械加速度计,文中介绍了静电刚度的谐振式微加速度计的工作原理,并根据闭环控制要求,建立了基于自激原理的系统分析方程,利用平均周期法分析了系统稳定性和振动幅度稳态平衡点。理论分析确定了系统起振条件和相位偏差对闭环振幅和频率的影响。对基于体硅溶片制造和真空封装的谐振微加速度计,自激闭环测试结果表明检测电压1 V时,灵敏度为18 Hz/g;检测电压5 V时,灵敏度为58 Hz/g,10 min内闭环谐振频率最大漂移0.2 Hz,可分辨加速度约3.5 mg.The principle of the resonant accelerometer based on electrostatic stiffness was introduced,and its dynamic model was built.According to the requirement of closed-loop control,control equations based on self-oscillation technology was also built for the system.With the help of the averaging method,the system stability was analyzed and the equilibrium for the vibration amplitude was achieved.The influence for vibration amplitude and excited frequency by system phase error was analyzed.Finally a resonant micro accelerometer is fabricated with bulk-silicon dissolved processes and vacuum packaged.Closed-loop experiment show the sensitivity of 18 Hz/g when sensing voltage is 1 V;sensitivity is 58 Hz/g when sensing voltage is 5 V.The maximal error for closed-loop resonance frequency during 10 minutes is 0.2 Hz and the resolution is about 3.5 mg.

关 键 词：微加速度计 谐振 自激 平均周期法 

分 类 号：TN911.71[电子电信—通信与信息系统]