ABSTRACT
Fermentation processes are dynamic (i.e., nonlinear and nonstationary) in nature, thus leading to many difculties in modeling. In addition, the lack of specic sensors makes certain variables inaccessible by online estimation. Measuring the state variables (the smallest possible subset of system variables that can represent the entire state of a dynamical system) is difcult, especially online, and its reliability is uncertain. The difculties encountered by the control engineer, when studying this type of process, result from the fact that the process model is based on nonlinear algebraic relations and differential equations. These difculties make the biotechnological process an excellent eld
17.1 Introduction ........................................................................................................................ 489 17.2 Model System .....................................................................................................................490
