Global finite-time observers are designed for a class of nonlinear systems that are uniformly observable and possibly non-Lipschitz. The non-Lipschitz conditions under which global finite-time observers exist are in terms of bounds of the varying rational powers of the increments of the non-Lipschitz nonlinearities. These are the same conditions under which semi-global finite-time observers wer...

We present a nonlinear observer for continuous time dynamic system with state delay, and randomly missing measurements. Using the Lyapunov energy (LE) functional, we derive sufficient conditions for the local asymptotic stability for the observer state error equations. The observer performance without and with missing measurements is evaluated by simulations implemented in MATLAB. The results v...

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...

Motivated by the fact that, for linear systems, existence conditions for a full order observer and for a reduced order observer are the same, we study relationship between full order and reduced order observers for general nonlinear systems. We employ coordinate transformations for dealing with reduced order observers. By restricting the change of coordinates to be linear, we obtain some equiva...

Using Tracking Differentiators in Designing Nonlinear Disturbance Observers for Uncertain SystemsNaser Kazemzadeh, Saeed BarghandanAbstractIn the present paper, a practical designing method has been proposed for a novel class of NDOs based on TD. Such NDOs can nearly estimate all uncertain disturbances (specifically disturbances without prediction information). Regarding the outstanding perform...

We consider a general class of nonlinear reduced-order observers and show that the global asymptotic convergence of the observation error in the absence of network-induced constraints is maintained for the emulated observer semiglobally and practically (with respect to the maximum allowable transmission interval) when system measurements are sent through a communication channel. Networks govern...