A multi-observer based estimation framework for nonlinear systems under sensor attacks

For general discrete-time nonlinear systems, we address the state estimation problem under sensor attacks. We provide a general estimation scheme, built around the idea of sensor redundancy and multi-observers, capable of reconstructing the system state in spite of sensor attacks and noise, for a large class of nonlinear plants and observers. This scheme has been proposed by others for linear systems and here we propose a unifying framework for a much larger class of nonlinear systems.