An ℋ∞ algorithm for the windsurfer approach to adaptive robust control

The windsurfing approach to iterative control requires a series of controller designs with the gradual expanding of the closed-loop bandwidth, and in the end in order to stop the algorithm, some validation tests are carried out. In this paper, an ℋ∞ design algorithm is introduced in order to remove the empirical aspect from the stopping criteria and to make the procedure more systematic, hence facilitating the design. Moreover, some restrictive assumptions on the plant model are lifted and some issues with the controller design step are tackled by the introduction of a new design method. This enables us to address a wider class of practical problems. Copyright © 2004 John Wiley & Sons, Ltd.