Adaptive tracking with saturating input and controller integral action

The authors consider the problem of controlling stable linear plants subject to input saturation constraints and parametric uncertainties. A globally stable adaptive controller which performs well in the presence of such constraints is designed, using a specific pole placement that accounts for the saturation constraint, an integral action to deal with the tracking problem, and an adaptive control law with an ad hoc excitation capability together with a parameter adaptation to cope with the parametric uncertainty. The proposed controller allows one to track slowly varying reference sequences. Particularly, in the case of a constant reference, the output tracking error vanishes asymptotically and the control input does stop saturating after a finite time.