Interval observers used in state estimation for a class of biodegradable polymers

This paper deals with the design of interval observers for estimation of some state variables in an uncertain biotechnological process. More exactly, using some interval observers, two biomass concentrations in a process that produces biodegradable polymers are estimated. Since the modelling of these processes is uncertain only some bounds of the two biomass concentrations can be estimated by using two appropriately interval observers. These limits depend on the known limits of the influent substrate concentration involved in the process. These observers are used in an adaptive controlling problem of a substrate inside of the reactor. The effectiveness and performance of these interval observers as well as of the adaptive control strategy are illustrated by numerical simulations applied in the case of a Poly-β-hydroxybutyrate bioprocess.