Interval observer for nonlinear Lipschitz systems with unknown inputs

This paper investigates the construction of an interval observer for nonlinear Lipschitz systems with unknown input. The nonlinear part of the considered system is made by a Lipschitz function. The idea of the proposed observer is to use the derivative of the output vector in order to decouple the unknown input from the interval error bounds. After recalling the useful assumptions, the observer is constructed and the interval error are proved to be asymptotically bounded. Finally, an example illustrates the theoretical contribution.