Robust H-infinity control of a class of continuous fermentation processes

This paper deals with the H-infinity control of a class of fermentation pro cesses that are described by an unstructured fermentation process model. Fo r a given dilution rate, an optimal controller has been developed which gua rantees the so-called L-2-gain from the disturbance to the error between th e substrate concentration and the desired optimal substrate concentration t o be no larger than a prescribed value in lieu of the system's uncertaintie s. The disturbance affecting the system's dynamics comes from the residue o f the feed substrate concentration, external noise, and unmodelled dynamics . It is stressed that this optimal controller requires only the substrate c oncentration to be measurable. (C) 1999 Elsevier Science Ltd. All rights re served.