BIOESTIM - SOFTWARE FOR AUTOMATIC DESIGN OF ESTIMATORS IN BIOPROCESS ENGINEERING

This paper describes BIOESTIM, a software package devoted to on-line e stimation in bioprocess engineering. BIOESTIM enables bioengineers aut omatically to design state and parameter estimators from a minimal kno wledge of the process kinetics. Such estimators allow development of s oftware sensors capable of coping with the lack of reliable instrument ation suited to real-time monitoring. The estimator building procedure through BIOESTIM starts up from a dynamical material balance model of the bioprocess. This model, supplied by the user, is next completed b y other information with no requirement for numerical values: the user has only to specify available measurements, coupled reactions and the known yield coefficients. On the base of this knowledge, BIOESTIM pro ceeds to symbolic algebraic manipulations on the model in order to stu dy estimation possibilities and check identifiability of yield coeffic ients. When the design of an estimator is possible, the corresponding equations are automatically generated. Moreover, these estimators are stored in a user-specified file which is automatically interfaced with a specialized simulation software including data treatment and numeri cal integration packages. Thus, the user can simulate the estimator pe rformances under various operational conditions using available experi mental measurements. A typical example dealing with microbial growth a nd biosynthesis reactions is given in order to illustrate the main fun ctional capabilities of BIOESTIM. BIOESTIM has been designed and writt en in a modular fashion. The module dealing with estimators design mak es use of symbolic computation; it is written in Mathematica and runs on every computer on which this language is available.