Track following control of hard disc drive: A survey

The head-positioning accuracy of the hard disc drive should be less than 10% of the track width to ensure that the user data on the adjacent track is not erased during writing. For that purpose the track-following controllers are used to minimize the value of Position Error Signal (PES) as small as possible for both the nominal and perturbed plants in the presence of disturbances & noise. A comparative study is done on different controllers (classical, robust & optimal) in this thesis to compare the efficiency of improving the performance of the track following control of HDD.