Observers for the biotechnological processes with unknown kinetics. Application to wastewater treatment

We present nonlinear observers for a class of biotechnological processes. These observers are an extension of the asymptotic observers (observers with unknown inputs) devoted to biotechnological systems for which some parts of the model are unknown. We take benefit of the outputs which are nonlinear functions of the state to design a closed loop observer. The global convergence of these nonlinear observers is proven. The method is illustrated with an experimental application to a water treatment process.