Patent ID: 6211638
Filing Date: 2001-04-03
Classification: G05B,G11B

Abstract:
A hard disk drive system, comprising:a rotatably supported magnetic disk;a member supported for movement relative to said disk;an actuator for effecting a first movement of said member;a microactuator supported on said member, said microactuator having a base secured to said member, having a platform supported for a second movement relative to said base, and having a drive arrangement which is operative to effect said second movement of said platform away from an initial position relative to said base in response to a control signal, said drive arrangement having a linear transfer function and a nonlinear transfer function which causes a displacement of said platform from the initial position to vary linearly and nonlinearly with respect to variation of the control signal;a read/write head supported on said platform of said microactuator, said read/write head being adjacent to said disk and being moved substantially radially of said disk in response to said first movement of said member by said actuator and in response to said second movement of said platform relative to said base; anda single control loop which is operative to generate the control signal, said single control loop including a first portion operative to generate a first signal that represents a linear force to be exerted on said platform in order to effect movement of said platform away from the initial position thereof, and a second portion which is operative to generate a second signal, said control signal being a function of said first signal and said second signal, said second portion operative to generate said second signal having a nonlinear transfer function which is substantially an inverse of the nonlinear transfer function of said drive arrangement.