An adaptive high-gain observer for wastewater treatment systems

The purpose of this paper is twofold: (1) we apply the adaptive observer developed in Boizot et al. [1] to a wastewater system, following two cascade steps. First, we apply it to a simplified model of the system. Second, we use this “simplified” estimation as a measurement for the full system. (2) Although the observability analysis is trivial, the equations contain rather complicated terms. Therefore, it is not reasonable to change coordinates for those of the required observability canonical form. Hence, we have to establish and work with the “unusual” equations of the observer in natural coordinates.Let us point out that the simulations are done taking into account the small number of measurements (three) available in practice.