Patent ID: 7636605

Claim:
A magnetic disk device comprising: a magnetic disk on which data is recorded; a head that performs recording and reproducing data with respect to the magnetic disk; a head driver that moves the head in a radial direction of the magnetic disk; and a positioning controller that issues a control command to the head driver to control the head to be located at a target position on the magnetic disk, wherein the positioning controller includes a feedback controller that performs a feedback control based on an error between the target position and an actual position of the head; and a model controller that obtains the control command, a model position to be output as a command for the target position to the feedback controller, and a model velocity for the head to follow a target velocity, by using a preset control equation model, and obtains the control command and the model position with the target position as an input, based on a differential value of the target velocity corresponding to a remaining distance from the model position to the target position, wherein the model controller obtains the control command and the model position based on a value obtained by multiplying the differential value by the model velocity.