Dynamic switching surfaces for output sliding mode control: An approach

The robustness properties of sliding-mode and H ∞ controllers are exploited to produce a dynamic output feedback controller that is insensitive to matched perturbations and attenuates the unmatched ones. The assumptions on the plant differ from the standard assumptions of the Riccati state-space approach to H ∞ control. The sliding-mode controller drives the state into a reduced-order manifold for which the equivalent system does satisfy the standard assumptions and hence the standard theory can be applied. The resulting Riccati equations are of reduced order.