Nanoscale track-follow performance for flexible tape media

The positioning accuracy achievable by track-follow servo for flexible tape media is investigated using advanced concepts for several elements of the system. First, the servo pattern geometry in the timing-based servo system is designed in conjunction with a digital synchronous servo channel to minimize the measurement error in the position-error signal. Second, a flangeless tape path is introduced to mitigate high-frequency components of the lateral tape motion. Finally, a track-follow controller is designed based on the H∞ approach, taking into account the disturbance and noise characteristics of tape path and servo-channel and the measured plant transfer function. Combining these elements with a new high SNR magnetic tape based on perpendicularly-oriented BaFe particles, we demonstrate a closed-loop track-follow performance with a standard deviation of the position-error signal of less than 15 nm. © 2011 IFAC.