FUZZY CONTROL OF AN ANAEROBIC DIGESTER FOR THE TREATMENT OF THE ORGANIC FRACTION OF MUNICIPAL SOLID-WASTE (MSW)

This paper deals with an application of the fuzzy approximate reasoning to the management and control of a pilot scale anaerobic digester. The organic fraction of MSW was used as substrate of the digester operating under semi-dry, thermophilic conditions. The fuzzy control actions suggested by the controller are taken on the basis of an emulation of expert reasoning instead of a mathematical representation of the digester behaviour. This approach is realized by capturing the expert's knowledge of the process through knowledge engineering methods. The controller performance was checked against the expert's behaviour for a set of experimental data. The experimentation has thus far proven that a controller for anaerobic reactors based on fuzzy logic is feasible and that the fuzzy approach provides a relatively simple description of human behaviour from different points of view.