Patent ID: 7054099

Claim:
For use in a disk drive system including a read/write head, an actuator assembly including a voice coil motor (VCM) that is used to control movement of the read/write head, and a VCM driver that drives the VCM, wherein the VCM has an associated back electromagnetic field (BEMF) constant, a method for controlling the deceleration phase of a seek operation that is used to move the read/write head to a desired velocity and a desired position in phase space, the method comprising: (a) obtaining a present (v i ) and a present position (x i ) of the read/write head; (b) selecting a deceleration profile, based on the present velocity (v i ), the present position (x i ) and the BEMF constant, wherein the deceleration profile defines a path in phase space from the present velocity and present position to a target velocity and a target position where it is useful to switch from the deceleration phase to a settling phase of the seek operation, rather than defining a path in phase space from the present velocity and present position to the desired velocity and the desired position, wherein the target velocity and the target position are offset, respectively, from the desired velocity and the desired position; and (c) supplying a control signal to the VCM driver in an attempt to have the read/write head follow the selected deceleration profile.