Application of Thau Observer for Fault Detection of Micro Parallel Plate Capacitor Subjected to Nonlinear Electrostatic Force

This paper investigates the fault detection of a micro parallel plate capacitor subjected to nonlinear electrostatic force. For this end Thau observer, which has good ability in fault detection of nonlinear system has been presented and governing nonlinear dynamic equation of the capacitor has been presented. Upper and lower threshold for fault detection have been obtained. The robustness of the observer to noise and uncertainty and sensitivity to fault has been investigated. Finally, simulation results for fault detection of the capacitor are presented and the ability of the observer in the vicinity of dynamic pull-in voltage has been checked.