NONLINEAR PROTEIN PRODUCTION TRACKING IN A FED-BATCH CULTURE
In fed-batch cultures the desired metabolite production
is achieved often following a predefined nutrient/
inducer feeding profile. Controlling a fed-batch
fermentation is not an easy task to achieve due to the
nonlinearities and uncertainities present in the kinetic
terms. In this paper a control strategy is designed to
track a trajectory in a nonlinear fed-batch culture producing
the protein luciferase through a recombinant
bacterium. The proposed control scheme has three
components: i) a nominal model, ii) a dynamic reduced
observer, and iii) a SISO non-linear feedback controller.
A linearizing control law provides the nonlinear
system with a closed loop linear behavior. Uncertain
terms related with the fermentation kinetics are gathered
in a function that is estimated with an observer.
From the control theory point of view, the problem of
estimating the uncertain kinetic terms is addressed as
a combination of Model matching and Tracking problems.
The proposed scheme is robust against modeling
errors. The observer based controller had satisfactory
perfomance tracking the desired trajectories.