Patent ID: 7031095
Filing Date: 2006-04-18
Classification: G11B

Abstract:
1. A hard disk drive, comprising: means for controlling a voice coil actuator contained in said hard disk drive by a control variable U based upon a measured read-write head position Ycur; and said hard disk drive further comprising at least one member of the collection comprising: means for seeking a first track located at a first head position by using said means for controlling said voice coil actuator to alter said measured read-write head position Ycur based upon said control variable U; and means for following said first track located at said first head position by using said means for controlling said voice coil actuator to maintain said measured read-write head position Ycur close to said first head position based upon said control variable U; wherein the means for controlling said voice coil actuator is further comprised of: wherein the means for calculating said control variable U based upon said measured read-write head position Ycur performs the steps of: wherein each member of a state vector collection includes a read-write head position version, a read-write head velocity version and an unknown bias force version; wherein said state vector collection includes said estimated state vector Xhat and said predicted state vector Xbar; wherein said hard disk drive includes a disk surface accessed by a read-write head at said measured read-write head position Ycur; wherein said disk surface contains multiple physical tracks at a Track Per Inch (TPI); and wherein said TPI is at least 80,000 tracks per inch.