Disk drive servo controller design using H_∞-LTR

摘要

Design of disk drive servo controller usingH_∞-optimization technique to recover the loop transferfunction is presented here. In the first phase of the two stepalgorithm, a full state feedback controller is designed to obtaindesired gain and phase margins, and satisfactory sensitivity andcomplementary sensitivity for the nominal plant model. The observergains are determined in the second phase, loop transfer recovery (LTR),so that the characteristics of the full state feedback are preserved.Recovery is achieved using minimization of the H_∞-normof a transfer function called the recovery function, which representsthe difference between the loop gain of the static full state feedbackand feedback with observer. Simulation results for the continuous timedesign are shown