Constrained linearization of embedded position error signals (PES) [magnetic disk storage]

Aggressive growth in areal densities in magnetic disk storage requires increasing accuracies in the tracking control system. This requires advances in the drive mechanics, sophisticated feedback/feedforward control strategies and the ability to obtain legitimate off-track position information from the drive media using advanced read/write heads. All the drive components are subjected to huge manufacturing tolerances that compromise design margins, requiring in-drive calibrations for yield improvements. In this paper, methods to improve the accuracy of position sensing are discussed