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

In this paper a novel method for construction of an exponential observer for nonlinear system is proposed. The method is based on direct solution of dynamic error without any linearizing 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 by implementing the observer for fault detection of micro tunable capacitor subjected to nonlinear electrostatic force.