Abstract A technique to identify feedthrough coupling in an unstable one degree-of-freedom electrostatic bearing is described. The feedthrough is caused by the simultaneous use of electrodes for differential capacitive sensing and electrostatic actuation. Cancellation of the feedthrough over a broad frequency band is necessary for the system to be practically stabilizable. A feedforward filter based on open-loop estimates of the feedthrough is adequate for designing a stabilizing controller, however, the resulting stability margins are poor because the closed-loop feedthrough differs from the open-loop estimates which determine the filter. The main contribution of the paper shows how the initial feedforward filter can be updated using feedthrough estimates obtained by testing the closed-loop system at its nominal operating point. It is demonstrated that the improved feedthrough cancellation facilitates the implementation of an updated controller which reduces sensitivity function peaking and increases the closed-loop bandwidth.

中文翻译：

---

不稳定静电轴承馈通的识别与补偿

摘要 描述了一种在不稳定的单自由度静电轴承中识别馈通耦合的技术。馈通是由同时使用电极进行差分电容传感和静电驱动引起的。消除宽频带上的馈通对于系统实际上是稳定的是必要的。基于馈通的开环估计的前馈滤波器足以设计稳定控制器，但是，由于闭环馈通与确定滤波器的开环估计不同，因此产生的稳定性裕度很差。该论文的主要贡献展示了如何使用通过在其标称工作点测试闭环系统获得的馈通估计来更新初始前馈滤波器。