Super-twisting estimation of a virtual output for extremum-seeking output feedback control of bioreactors. (November 2015)

• Record Type: Journal Article
• Authors: Vargas, A.; Moreno, J.A.; Vande Wouwer, A.
• Is Part Of: Journal of process control. Volume 35(2015:Nov.)
• Page Start: 41
• Page End: 49
• Publication Date: 2015-11
• Subjects: State estimation -- Output feedback -- Sliding mode observer -- Bioprocesses -- Extremum seeking; Process control -- Periodicals; Fabrication -- Contrôle -- Périodiques; Process control; Periodicals; Electronic journals; 660.281
• DOI: 10.1016/j.jprocont.2015.08.003
• Languages: English
• ISSNs: 0959-1524

Abstract

Abstract : Highlights: A virtual output that is a linear combination of reaction rates should be maximized. A bank of super-twisting observers carry out the estimation of the virtual output. A weighted super-twisting observer with constant gains is proposed. A two-level output feedback controller is proposed to maximize the output. The resulting output-feedback controller is tested with simulations of a bioreactor. Abstract: In biotechnological processes such as fed-batch reactors the lack of reliable and robust on-line sensors and the limited number of actuators make the task of operating at optimal conditions very difficult. We present a feedback controller that aims at regulating the substrate concentration at an optimum value such that biomass production is enhanced while by-product formation is not favored. We use a virtual output that is estimated using a bank of weighted super-twisting observers to drive an output-feedback extremum-seeking controller. The only online measurements needed are the biomass concentration and the oxygen and carbon dioxide mass transfer rates. Simulations on a fed-batch bioreactor model show its applicability.