Patent ID: 8817416

Claim:
A magnetic disk device, comprising: magnetic heads; a magnetic disk in which servo patterns having different write frequencies are divided and recorded into a plurality of zones; and a head controller configured to correct a model position and a model velocity obtained from a model simulating the magnetic head, at the time of switching of the zones, so as to reflect variation of sampling time resulting from gaps between the zones when performing seek control of the magnetic heads based on the model position and the model velocity, wherein, when the model is expressed as an inertial system, the zones are switched between time k and time k+1, a model position before correction is MPB(k+1), a model velocity before correction is MVB(k+1), a model manipulation amount is ME(k), sample time is T, gap time is dt, and A1 and A2 are gains, a model position after correction MPA(k+1) and a model velocity after correction MVA(k+1) are given by equations: MPA ( k+ 1)= MPB ( k+ 1)+ MVB ( k+ 1)* dt/T+Al*ME ( k )*( dt/T ) 2 MVA ( k+ 1)= MVB ( k+ 1)+ A 2 *ME ( k )* dt/T.