New publication

04-05-2018 "Output feedback linearization of turbidostats after time scaling", IEEE Trans. on Control Systems Technology, 2018,  just accepted

Turbidostats are a class of bioreactors gaining in- terest due to the recent availability of micro- and small-scale devices for characterization and scaling-up of biotechnological systems relevant in the biotech and pharma industries. The goal is to keep cell density constant in continuous operation. Thus the control law, i.e. the substrate feeding strategy, must guarantee global or semiglobal convergence to an equilibrium point. However, their control is difficult due to the uncertain, time-varying and nonlinear nature of the processes involved. In this paper we propose an adaptive control law that globally stabilizes the desired biomass set-point. Further, in a certain region of the state space the controller linearizes the dynamic behavior after some time scaling. This way, the orbits of the closed loop system are imposed by the designer. The intrinsic integral action of the gain adaptation rejects parameter uncertainties. Moreover, the controller implementation only assumes biomass concentration to be measured. Both simulated and experimental results show the performance of the controller.