Head positioning control of a hard disk drive using H∞ theory

The purpose of the head positioning control of hard disk drives is to move the magnetic head onto the desired track swiftly and to keep it on the track precisely against various disturbances and plant uncertainty at high frequency. The authors apply H^∞ control to the head positioning of hard disk drives. To obtain a good transient response, they adopt the two-degree of freedom control scheme. The experimental results show a favorable control performance and indicate a very promising future for the application of the H ^∞ control theory to hard disk control systems