静电悬浮电机通过可控的静电力将转子无接触地悬浮起来,具有极高的工作寿命,可用作力平衡式三轴加速度计或双轴角速率陀螺。研制的转子静电悬浮式微电机采用差动电容式微位移传感器来精确检环形转子在电极腔内的运动,然后借助于悬浮控制系统来实现转子的五自由度有源静电悬浮。文中介绍了基于公共激励电极方案的微位移检测电路,并进行了设计仿真和实验测试。仿真分析和实验测试表明,设计的电容式位移检测电路可用于MEMS微静电悬浮电机的悬浮控制系统。
Micromotors with the electrostatically levitated rotor in electrode cavity behave long duration of opera- tion, and can be used as a dual-axis gyro or a force-balanced tri-axis accelerometer. The position of the rotor in those electrostatic levitation-based micromotors is usually detected by sensing the differential rotor-electrode capacitance and further fed back to multi-axis active levitation control loop with an aim to keep stable suspension of the rotor. In this paper, theoretical analysis and experimental data of a capacitive position sensing interface based on common excita- tion-electrode scheme is presented for an electrostatic levitation-based micromotor. The simulation and experimental performance indicate that the proposed capacitive interface circuit can be used to achieve multi-axis electrostatic sus- pension of the rotor for such micromotors fabricated by MEMS technology.