Analysis of sliding mode proximate time-optimal disk drive servo control

An analysis of a sliding mode proximate time-optimal servomechanism (SPTOS) conducted through simulations and experiments is presented. The sliding mode is utilized to deliver proximate time-optimal performance naturally. We also examine why the SPTOS scheme is superior to the proximate time-optimal servomechanism that is widely used in the disk drive industry. The SPTOS is shown to produce bounded motion along the reference profile, which contributes to accurate reference profile tracking even in the presence of plant uncertainties. The application of the SPTOS yielded accurate reference velocity profile tracking as well as uniformly excellent seek performance regardless of the seek length.