Patent ID: 6563665
Filing Date: 2003-05-13
Classification: G11B

Abstract:
A servo control system for controlling a dual stage actuator in a disc drive having a data head accessing information on a disc surface, the dual stage actuator including a coarse actuator and at least one fine actuator, the servo control system, comprising:a fine actuator driver coupled to the fine actuator to drive the fine actuator; a coarse actuator driver coupled to the coarse actuator to drive the coarse actuator; a feedback circuit receiving a position signal, indicative of a measured head position, based on position information read by the data head and comparing a desired head position to the measured head position; and an observer coupled to the feedback circuit to receive signals provided to the fine and coarse actuators and to provide an estimated signal to at least one of the fine actuator driver and the coarse actuator driver to estimate response of the fine or coarse actuator.