A new robust observer approach for unknown input and state estimation

This paper proposes a new approach for a robust estimation of unknown inputs as well as state variables in a dynamical system subject to noise or uncertainties. Following a recently proposed control-based methodology for observer design, the idea here is to take advantage of robust control methods, and in particular of
H
_∞
techniques. This provides a new method which is applied for an example of tunneling current estimation in an STM-like device. Simulation results are finally provided together with a comparison to the formerly available
H
_∞
filtering, but also to the robust sliding-mode technique.