Nonlinear observers for parameter estimation in bioprocesses

In this paper, we propose simple nonlinear observer-based estimators for the on-line estimation of kinetic rates in fermentation processes. These estimators, designed in continuous and discrete-time, do not assume or require any kind of specific relationships between the reaction rates and the state variables. Moreover, they are very easy to implement and in particular to calibrate. Indeed, the gain of the proposed estimators does not require the resolution of any dynamical system and it is explicitly given. Furthermore, due to the particular structure of this gain, the tuning of the estimators is reduced to the calibration of a single parameter and this whatever the number of considered components and reactions. Numerical simulations and real-life experiments have been carried out and corresponding results are given in order to highlight the performance of the proposed estimators. (C) 1997 Elsevier Science Ltd.