Design of Direct Exponential Observers for Fault Detection of Nonlinear MEMS Tunable Capacitor

In this paper a novel method is proposed for construction of an exponential observer for nonlinear system. The presented method is based on direct solution of dynamic error without any linearzing of nonlinear terms. Necessary and sufficient conditions for construction of direct observer are presented. Stability of the observer is checked using Lyapunov theorem. Also the ability of this observer is checked with implementing of observer for fault detection of micro tunable capacitor subjected to nonlinear electrostatic force.