Design and Modeling of Anti Wind Up PID Controllers - Complex System Modelling and Control Through Intelligent Soft Computations - page 12

Fig. 7 Saturated input with AWC controller compensation
Fig. 8 Saturated input with no AWC controller compensation
These unwanted effects lead to the system performance deterioration, as
explained before, Therefore a correction signal send to the internal model controller
corrects and improves the system performance deterioration, yielding better system
characteristics in comparison when there is no anti windup compensation.
Finally, as a conclusion of this section, it was proved that is possible to stabilize
a saturated system by anti windup control compensation, when the system is a
single input single output continuous time model, independently of the saturation
and the unwanted effects yielded by the windup, generated by the increasing of the
integral action. In the next section the discrete time counterpart of the IMC PID anti
windup controller is derived, following the internal model control guidelines for the
design of an appropriate anti windup controller for this kind of models.