电容式力平衡加速度计的设计

电容式微机械加速度计是一种将加速度转换成差分电容、通过检测差分电容的变化来检测加速度大小的一类高精度的惯性传感器。利用开关电容电路实现C-V变换,利用反馈静电力实现力平衡闭环控制,设计了一种电容式微机械加速度计。通过构建电容式加速度传感器及外围电路的数学模型,推导了闭环工作的系统函数。并对实际系统进行研制,最后给出了整个系统的测试结果。

Design of Force-Balance Capacitive Accelerometer

Micro-mechanical capacitive accelerometer is one kind of high sensitive inertial sensors which convert the acceleration to differential capacitance and the acceleration value can be obtained by detecting the variation of the micro defferential capacitance. Using the switching capacity circuit to realize the C-V convert and using the feedback of the electrostatic force to realize force-balance closed-loop control, the micro-mechanical capacitive accelerometer is designed. The mathematic model of the capacitive accelerometer and its peripheral interface circuit is set up. On this basis, the transfer function of the closed-loop operation system is derived. And the measurement results on the system is shown too.