硅微静电加速度计轴间耦合自锁研究

he micro-machined electrostatically suspended accelerometer (MESA) is a kind of three-axis inertial sensor based on differential capacitive position sensing and electrostatic force feedback. Our previous experiments showed that it is difficult to levitate the proof mass of a MESA successfully in all six degrees of freedom (DOFs) since the translation along the Y-axis and the rotation around the Z-axis often stay still, although the control voltage has reached its upper limit. By analyzing the coupling electrostatic force and torque, it is found when the rotation angle around the Z-axis is over 55% of the allowable range, the cross-axis coupling force from the X-axis electrodes will be stronger than the control force generated by the Y-axis electrodes, which means the proof mass will come into a self-locking zone. Through delaying the operation of the X-axis suspension control with a time of 62ms, the proof mass can be levitated in six DOFs at any initial position, which solves the initial levitation problem for multi-axis MESAs with electrostatic suspension.