Model-reference output-feedback sliding mode controller for a class of multivariable nonlinear systems

This paper proposes an output-feedback sliding mode control design for a class of uncertain multivariable plants with nonlinear disturbances. The approach used here is based on the control parameterization employed in model-reference adaptive control. The disturbances are allowed to be unmatched and to depend not only on the plant output but also on its unmeasurable state. A less restrictive condition on the uncertainty of the high frequency gain matrix is also obtained.