Enhancement of hard disk drive manipulator using piezoelectric actuator mechanisms

This paper discusses the employment of piezoelectric actuators (PEA) to encompass high precision-scale movement capability of magnetic hard disk drive servo systems. To overcome path/positioning limitations of previous hard disk servo systems, a new design consisting of three PEAs links is proposed. Two different controllers, namely PI and fuzzy, are designed and simulated to assess the performance of the proposed design over a couple of paths under the presence of noise and disturbance. Simulation results show that the proposed design is able to track complex paths over a wider spectrum of motion than conventional hard drive servo systems. This improves the read-write process by affording nanoscale motion and provides high levels of positioning accuracy, as well as wide spectrum of positioning capability. Moreover, both controllers reveal the ability to drive the mechanism with quick response and minimal overshoot, with the fuzzy controller outperforming the PI controller under the presence of noise and disturbance.