Abstract
In this paper, we designed robust controllers for a track-following system in magneto-optical (MO) disk drives, and succeeded in reducing the order of controllers for practical use. We estimated the performance of robust controllers and confirmed that tracking error could be reduced by about 60% compared with a conventional PID controller. We also estimated achievable tracking accuracy while changing the three dominant parameters that restrict the performance of the control system : frequency of mechanical resonance, sampling frequency of the feedback controller, and specifications for robust stability.
