Parametric Uncertainty Modeling and Multiple Controller Design for Hard Disk Drives

This paper proposes a new design procedure for track-following control systems in hard disk drives. The procedure is automated, in the sense that, for given experimental frequency response data of the suspension arm dynamics and a model structure, it automatically derives a transfer function set with uncorrelated parametric uncertainties. Subsequently, for the transfer function set, a given controller structure, and closed-loop performance specifications in the frequency domain, it automatically designs a partition of the uncertainties and corresponding multiple robust controllers. Experiments on actual hard disk drives demonstrate the usefulness and efficiency of the proposed procedure.