Robust Repetitive Perfect Tracking Control of HDDs Based on Re-learning Scheme

抄録

This paper presents an improved method of a repetitive controller based on perfect tracking control (PTC) in order to reject the variable repeatable runout (RRO) of hard disk drives (HDDs). The author's group proposed repetitive PTC (RPTC) with a switching mechanism. RPTC is realized by using periodic a signal generator (PSG) and PTC. The PSG produces a feedforward signal from the periodic disturbance, and the PTC generates a control input to cancel the periodic error in the steady state. However, we have not considered the difference between the RROs of tracks. This paper proposes a re-learning scheme by taking into account the correlation of adjacent tracks. Finally, the advantages of RPTC using the proposed scheme are demonstrated through simulations and experiments using a hard disk drive equipment with discrete track recording media (DTR).