Sliding-mode state estimation for a class of multi-output nonlinear continuous-time systems

We extend previous results on sliding-mode observers for continuous-time nonlinear dynamic systems by considering a multi-output linear measurement equation. The nonlinearities of the system are assumed to be globally Lipschitz. Conditions that ensure the stability of the estimation error are presented that can be expressed in terms of Linear Matrix Inequalities (LMIs). Such conditions are less restrictive with respect to those available in the current literature on sliding-mode estimators for nonlinear systems, as they allow the design of observers with asymptotically stable error also for system with a nonlinearity that is characterized by a large Lipschitz constant. Simulation results for an application of the proposed observer to state estimation with a dynamic model of TCP flows are reported.