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DISCO - 2017
Overall Objectives
New Software and Platforms
Bilateral Contracts and Grants with Industry
Bibliography
Overall Objectives
New Software and Platforms
Bilateral Contracts and Grants with Industry
Bibliography


Section: New Results

Chemostat

Participants : Frederic Mazenc, Michael Malisoff [LSU,USA] , Gonzalo Robledo [Univ. de Chile,Chile] .

A chemostat is a fundamental bioreactor used to study the behavior of microorganisms. Many different types of chemostats exist, and many different types of models represent them.

We studied in [56] a chemostat model with an arbitrary number of competing species, one substrate, and constant dilution rates. We allowed delays in the growth rates and additive uncertainties. Using constant inputs of certain species, we derived bounds on the sizes of the delays that ensure asymptotic stability of an equilibrium when the uncertainties are zero, which can allow persistence of multiple species. Under delays and uncertainties, we provided bounds on the delays and on the uncertainties that ensure a robustness property of input-to-state stability with respect to uncertainties.

In [16], we provided a new control design for chemostats, under constant substrate input concentrations, using piecewise constant delayed measurements of the substrate concentration. Our growth functions can be uncertain and are not necessarily monotone. The dilution rate is the control. We use a new Lyapunov approach to derive conditions on the largest sampling interval and on the delay length to ensure asymptotic stabilization properties of a componentwise positive equilibrium point.