Uncertainty weight selection for H-infinity and mu-control methods

The authors give some insight into H_∞-weight selection from a process control perspective, with emphasis on uncertainty modeling. They study how to transform parametric gain-delay uncertainties into frequency-dependent weights specifying norm-bounded uncertainties. They postulate a parametric gain delay uncertainty set as the true uncertainty. They then try to minimize an uncertainty set generated by a complex additive perturbation which covers the true set. In addition, μ-optimal controllers are designed for the example problem considered. Simulation results are presented