Decentralized direct adaptive Fuzzy-Neural control of an anaerobic digestion bioprocess plant

The paper proposed to use Fuzzy-Neural Multi-Model (FNMM) identification and control system for decentralized control of distributed parameter anaerobic wastewater treatment digestion bioprocess, carried out in a fixed bed and a recirculation tank. The distributed parameter analytical model of the digestion bioprocess is reduced to a lumped system using the orthogonal collocation method, applied in three collocation points (plus the recirculation tank), which are used as centers of the membership functions of the fuzzyfied space variable of the plant. The states of the proposed FNMM identifier are implemented by a direct feedback-feedforward hierarchical FNMM controller. The comparative graphical simulation results of the digestion anaerobic system control, obtained via learning, exhibited a good convergence, and precise reference tracking outperforming the optimal control.