Tae-Yong Doh

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In mode switching control from the track seeking or the track jump to the track-following control of hard disk drives, initial values of the feedback controller are tuned in order to improve the transient response. This paper presents a simple initial value compensation (IVC) method using linear matrix inequalities (LMIs) instead of the conventional method(More)
Considering an uncertain plant in iterative learning control (ILC), robust convergence and robust stability are important issues. Since the feedback controller robustly stabilizes the uncertain plant and has an e€ ect on the convergence, it plays as signi® cant a role as the learning controller does in the ILC system. To deal with both convergence and(More)
In this paper, a compensator design method is presented for track-following control in an optical disk drive, a common mechanism for which is a dual-stage actuator composed of a fine and a coarse actuators. Most of previous works, however, have focused on tracking precision enhancement using only the fine actuator without systematic design method for a(More)
A repetitive controller has been applied owing to its prominent capability for attenuating periodic disturbances and/or tracking periodic reference commands. A repetitive controller is generally added on the existing feedback control system to improve the tracking performance. However, the repetitive controller has been designed without utilizing the(More)
This note deals with the problem of designing an iterative learning control for uncertain systems. Given a linear time-invariant plant with multiplicative perturbations, a suucient condition for the convergence of the learning process for all the plant uncertainty is derived. Based on the obtained suucient condition, we show that the iterative learning(More)