Patent ID: 6407876
Filing Date: 2002-06-18
Classification: G11B

Abstract:
A magnetic disk apparatus comprising:a recording medium on which servo signals are written; a head which reads said servo signals; a carriage which supports said head; a sensor which detects a state of said head or said carriage; and a processor comprising: an estimator which estimates a quantity about a state of said head or said carriage, by using an output of said sensor and said servo signals at a sampling time of said servo signals, and by using an output of said sensor at a sampling time of said sensor; a loop which feeds back said quantity thus estimated of said head or said carriage; a compensator which compares deviation of said head with said servo signals thus detected to compensate error signals to become zero; a control object model; a second compensator which controls said control object model; and a loop which feeds back an output of said control object model to said second compensator.