Extremum Seeking Control of Batch Cultures of Microalgae Nannochloropsis Oculata in Pre-Industrial Scale Photobioreactors

Model-Free Extremum Seeking Control of Bioprocesses: A Review with a Worked Example

“…Most of the publications discussed in this review propose simulation results in order to provide some practical assessment and recommendations in view of future experimental implementation. Among the very few experimental validations reported in the literature, two investigations aiming at maximizing microalgae culture productivity by extremum seeking have been proposed in [75,102].…”

“…In [75], the method consists of modulating the pH to optimize the measured Nannochloropsis Oculata microalgae biomass growth rate, using the CO 2 "flow as actuator" in an internal loop regulating the pH. In this regard, a perturbation-based filter bank ES was first designed in a simulation and some tuning guidelines were suggested as follows:…”

“…The first experimental validation of BOF-ES in the field of bioprocess optimization can be attributed to [75] optimizing microalgae growth at pre-industrial scale by manipulating the pH. Overall, BOF-ES can definitely be considered as a useful, practical, and easy-to-implement solution to optimize bioprocesses as long as operating conditions, dithers and controlled variables are carefully selected with respect to system dynamics.…”

Achievable performances for basic perturbation-based extremum seeking control in Wiener-Hammerstein plants

“…Although the results presented here will be limited to this ideal case, they can be transposed as a tuning method for practical situations (time-varying dynamics and non-quadratic nonlinearities) as long as the uncertainties on the available model of the system remain within certain tolerance levels (discussed later in this paper). The ideas presented here were effectively applied by our group to such a situation (in [7]), being to our knowledge the first implementation of ESC on a real bioprocess.…”

“…Its main advantage of not being model-based and requiring minimal information about the system to optimize has fostered numerous practical applications of the technique (e.g. [5,6,7]). Despite recent progress in the field, there still lacks convenient methods for tuning the ESC and improving its transient performances [8,9,10].…”