ISS feedback redesign for disturbance attenuation in continuous stirred tank reactors

In this paper a nonlinear feedback control law for a continuous stirred tank reactor (CSTR), obtained by exact I/O linearization and Sontag's ISS (input-to-state stability) feedback redesign methods, is studied. By the new feedback control law, local ISS of the overall control system with respect to unknown actuation disturbances is achieved. A significant attenuation of the disturbance is guaranteed, with evident improvement with respect to control laws obtained by the exact I/O linearization method. The performed simulations validate the theoretical results.