Modeling and estimation strategies for a fed-batch prototype bioprocess

Abstract

This paper deals with the Bond Graph modeling and the design of estimation strategies for a nonlinear fed-batch prototype bioprocess. The proposed strategies are developed for an aerobic microbial growth process coupled with an enzyme-catalyzed reaction, which is a usual bioprocess that takes place in fed-batch bioreactors. The rules for the design of pseudo Bond Graph model are obtained by using the reaction schemes and the analysis of biochemical phenomena. Two kinds of on-line estimation strategies are approached. First, a general state observer is analyzed and the exponential observability of the bioprocess is tested; two state estimation algorithms are designed: an extended Luenberger observer and an asymptotic observer. Second, an observer-based estimator is derived for the estimation of unknown kinetics. In order to test the behavior of proposed strategies, numerical simulations are included.