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 tononlinear electrostatic force. For this purpose, Thau observer, which has demonstrated good performance in fault detection of nonlinear systems,as well asgoverning nonlinear dynamic equation of the capacitor,is presented. Upper and lower threshold for fault detection have been obtained. The robustness of the observer to noise, uncertainty as well as sensitivity to faults wasinvestigated. Finally, simulation results for fault detection of the capacitor are obtained and the ability of the observer in the vicinity of dynamic pull-in voltage has been checked.