IMPROVEMENT OF SEEK-SETTLING PERFORMANCES BY DYNAMIC NONLINEAR CONTROL IN HARD DISK DRIVE SERVO SYSTEMS

摘要

A dynamic nonlinear control scheme to improve the seek-settling process in hard disk drive (HDD) servo systems is proposed. In order to reduce the impact of the control gains on the tracking performance, tracking differentiator (TD) is introduced as a dynamic reference of the feedback controller. The problems of the large and small gain control theory do not arise with this method, and the actuator saturation can be avoided as well. The stability analysis is given through Lyapunov functions. Simulation and experiment results show that the proposed control scheme performs well for both short and long seeking length.