An adaptive H∞ tracking control for a class of nonlinear multiple-input-multiple-output (MIMO) systems

An adaptive H-infinity tracking control equipped with a VSC algorithm is proposed for a class of nonlinear multiple-input-multiple-output (MIMO) systems that are represented by input-output models involving parametric uncertainties, unmodeled perturbations and external disturbances. In order to counteract the effect due to the unmodeled perturbation in the input weighting gain the H-infinity tracking control requires to solve a modified algebraic Riccati-like matrix equation. The derived hybrid adaptive-robust tracking control schemes guarantee that all the signals and states are bounded, the tracking error is uniformly ultimately bounded and an H-infinity tracking performance is achieved. Compared with the conventional H-infinity tracking control design the developed adaptive-robust H-infinity tracking control scheme can be applied to a broader class of nonlinear MIMO systems in the presence of high-degree uncertainties.