微机械振动电场传感器闭环自激驱动建模及系统仿真

本文针对微机械振动电场传感器灵敏度受驱动控制电路参数和谐振频率漂移影响问题，利用平均周期法对不同闭环自激驱动下微机械电场传感器的灵敏度进行了建模分析，理论和仿真分析表明：加入满足约束条件的PI控制器，灵敏度变化与屏蔽层固有谐振频率漂移和品质因数变化无关；加入满足约束条件的PI控制器比没有PI控制器的灵敏度大；PI控制器的参数不满足约束关系，输出电压不稳定，输出失真。

Modeling and numerical simulation of Closed-loop Control for an Electric Field Micro-Sensor

Because sensitivity of a micro mechanical resonant electric field sensor is influenced by the parameters of driving circuit and drift error of resonance frequency,a dynamic model was built for the micro sensor,and it ana-lyzed the system behavior and sensitivity on different closed loop self-excited circuits using averaging method in this paper. Theory and simulation results show that with the help of PI controller,the sensitivity is constant regardless of variations in shielding layer resonance frequency and Q-factor;the sensitivity with a suitable PI controller is larger than the sensitivity without a PI controller;if the parameters of PI controller do not satisfy the constraint relation-ship,output voltage is not stable and the sensitivity is distortion.