Intelligent control of an anaerobic digester: fuzzy-based gain scheduling for a geometrical approach

In this paper, an intelligent control scheme for a class of anaerobic digester, for wastewater treatment, is proposed. The control scheme results from the combination of nonlinear output feedback control and a fuzzy-based gain scheduling scheme. Such a controller achieves the substrate regulation in the face of modeling errors (which are mainly related to the kinetic terms). In addition, the controller shows the capability of attenuating load disturbances and windup effects due to constraints at the manipulated input. Extensive simulations illustrate the performance of the proposed control scheme.