Mems-fabricated Accelerometers with Feedback Compensation

This paper presents a feedback-controlled, MEMS-fabricated microaccelerometer. The microaccelerometer has received much commercial attraction, but its performance is generally limited. To improve the open-loop performance, a feedback controller is designed and experimentally evaluated. The feedback controller is applied to the x/y-axis microaccelerometer fabricated by sacrificial bulk micromachining (SBM) process. Even though the resolution of the closed-loop system is slightly worse than openloop system, the bandwidth, linearity, and bias stability are significantly improved. The noise equivalent resolution of open-loop system is 0.615 mg and that of closed-loop system is 0.864 mg. The bandwidths of open-loop and closed-loop system are over 100 Hz. The input range, non-linearity and bias stability are improved from ±10 g to ±18 g, from 11.1 %FSO to 0.86 %FSO, and from 0.221 mg to 0.128 mg by feedback control, respectively. Copyright © 2005 IFAC