Robust adaptive stabilization and tracking of type-1 plants in presence of input constraint

We consider the problem of controlling nonminimum phase type-1 plants in presence of model uncertainty and a saturation constraint imposed on the control input. We focus on plants that can be described by a nonminimum phase type-1 model. The control objectives include: 1) robust global asymptotic stabilization of the controlled plant; 2) output regulation in presence of external perturbations; and 3) tracking of output reference trajectories. The problem is dealt with using a saturated (indirect) adaptive regulator, based on a specific pole placement of the closed loop poles. The stability robustness is ensured with respect to a multiplicative modeling error. The obtained regulation and tracking performances are such that the slower the reference trajectory and the perturbation sequence, the better the quality of the tracking and regulation performances