Abstract
This paper describes designing a controller of a hard disk drive for rejecting disturbances using mixed sensitivity approach. Position Error Signal (PES) is consist of Repeatable Runout (RRO) and Non-Repeatable Runout (NRRO), NRRO is decomposed into its contributing component which are force disturbance, mechanical vibration, and etc, in frequency domain. To simulate the behavior of the disturbance signals, the decomposed signals are transformed to time domain. The H^∞ control design can be eliminated such disturbances effectively. A mixed sensitivity approach is applied to the robust controller design of the track-following control for the HDD. We compare between the results with a conventional controller and the results with the proposed controller. it shows the validity of the proposed controller design method.
