Error Prediction Robust Tracking Control System Suppressing Harmonics Disturbance for Optical Disk Recording System

Abstract

Recently, the memory capacity of media for the optical disk recording system has been increasing. The disk rotation speed has been increasing depending on the large memory capacity. However, the optical disk recording system has both periodic primary disturbance and periodic harmonics disturbance. Hence, the tracking control of the optical disk recording system is requested to maintain a high-precision tracking performance. We have proposed the robust tracking controller and zero-phase error tracking feed-forward control systems. Results of our study show that the primary disturbance is well suppressed by our conventional method, but it is difficult for our conventional method to suppress the harmonics disturbance. To overcome this problem, in this paper, we propose a new error prediction robust tracking control system suppressing harmonic disturbance. The experimental results show that the proposed tracking control system has a precise tracking response against both periodic primary disturbance and periodic harmonics disturbance.