电容式微机械陀螺接口电路  

An Interface Circuit for Capacitive Vibratory Microgyroscopes

作　　者：蒋庆华[1] 苑伟政[1] 常洪龙[1] 

机构地区：[1]西北工业大学微/纳米系统实验室,西安710072

出　　处：《传感技术学报》2006年第05B期2223-2225,共3页Chinese Journal of Sensors and Actuators

基　　金：国家自然科学基金项目资助(50505038)

摘　　要：接口电路是电容式微机械陀螺研制中的关键技术之一.给出了一种通用的电容式微机械陀螺接口电路方案.该方案包括电容检测和信号处理两个模块.相位相反幅度相同的两路高频载波加在敏感差动电容的两端形成敏感电桥,另一频率的高频载波叠加了驱动信号后加在驱动差动电容两端形成驱动电桥,质量块作为所有电容的公共端连接两电桥接虚地的放大器,构成前置电容检测模块;后续的带通滤波电路将驱动和敏感信号分离,各自解调滤波得到两个模态相应的振动信息,驱动振动对敏感振动再次解调即可得到和输入角速度信号成线性关系的直流电压.采用音叉电容式陀螺进行实验,结果表明该电路能够有效的能够有效的抑制寄生电容和各个接口电容之间电耦合的,电容分辨率可以达到10-15F.In order to achieve a high sensitivity and low drift,capacitive vibratory microgyroscopes need a very sensitive detection scheme. This paper presents an interface circuit for capacitive vibratory microgyroscopes including the detection bridge and the signal conditioning. The bridge consists of the differential driving capacitors, which is driven by two reverse ac signals consisting of one high frequency carrier voltage and the driving voltage. The other half bridge of sensing has the similar configuration. Two half-bridges share the same output node which is connected to the capacitances-to-voltage circuit based on virtual ground technology. Since the driving and the sensing using the different high frequency carrier voltage, Band pass filters is used to separate these two signals. Using the commercial operational amplifiers and demodulators, the experiments indicate that the circuit can effectively prevent the influence of stray capacitance and suppress the couplings of the driving and sensing signal. The capacitance resolution can reach 10^-15F.

关 键 词：微机械陀螺 电容检测 电桥 电荷放大器 接口电路 电容传感器 

分 类 号：TH7[机械工程—仪器科学与技术] V241.5[机械工程—精密仪器及机械]