Software sensors in bioprocess engineering

This paper deals with the design of 'software sensors' in bioprocess engineering. At first, it is shown, through an illustrative example, that a 'software sensor' which associates a sensor (hardware) and an estimation algorithm (software)-in order to provide on line estimation of unmeasurable variables-is a useful tool in bioprocess monitoring and control. Then, the possible design techniques appropriate to bioprocesses are presented; they hardly depend on the properties of the bioprocess model. Only the estimation methods based on reliable mass balance models with time varying kinetics parameters are considered. In order to aid the designer in his task, without requiring a deep knowledge of the underlying estimation theory, a knowledge based software, named BIOESTIM, is presented the facilities offered by this software, which includes expertise in system analysis and estimation theory, show it is a powerful tool in Computer Aided Estimation of bioprocesses. (C) 1997 Elsevier Science B.V.