“…A feedforward action is required in most cases to mitigate the effect of disturbances in the signal to be controlled (Berenguel, Camacho, & Rubio, 1993;Camacho, Rubio, & Hughes, 1992;Camacho et al, 1997;Carotenuto, LaCava, Muraca, & Raiconi, 1986;Meaburn & Hughes, 1996;Rorres, Orbach, & Fischl, 1980;Silva, Filatov, Lemos, & Unbehauen, 1998). In fact, the required system response cannot be guaranteed with a simple linear control technique because of the strong nonlinearities of the plant.…”