Observer-based synchronization and unknown input recovery for discrete-time Lipschitz nonlinear systems

This paper deals with the synchronization and unknown input recovery problem for discrete-time Lipschitz systems based on a nonlinear observer design approach. Stability conditions for the existence of asymptotic observers are established in terms of linear matrix inequalities. It is proven that the proposed conditions are less conservative than some existing ones in recent literature. Moreover, the observer design method is used to address the problem of synchronization and input recovery for a class of nonlinear systems in the presence of disturbances in both the state and output equations. Finally, a numerical example is provided to illustrate the effectiveness of the proposed design.