Adaptive Feedforward Reference Design for Active Vibration Rejection in Multi-Actuator Hard Disk Drives

TL;DR

This paper proposes an adaptive feedforward control method to improve vibration rejection in multi-actuator hard disk drives with dual-stage actuators, enhancing performance by mitigating disturbance effects on the shared pivot.

Contribution

It introduces a robust adaptive feedforward reference design as an add-on to existing controllers for multi-actuator HDDs, addressing disturbance transfer issues.

Findings

Effective vibration suppression demonstrated in simulations

Improved stability and performance of multi-actuator HDDs

Enhanced disturbance rejection capability

Abstract

In December 2017, Seagate unveiled the Multi Actuator Technology to double the data performance of the future generation hard disk drives (HDD). This technology will equip drives with two dual stage actuators (DSA) each comprising of a voice coil motor (VCM) actuator and a piezoelectric micro actuator (MA) operating on the same pivot point. Each DSA is responsible for controlling half of the drive's arms. As both the DSAs operate independently on the same pivot timber, the control forces and torques generated by one can affect the operation of the other and thereby worsening the performance drastically. In this paper, a robust adaptive feedforward controller is designed as an add-on controller to an existing stabilizing feedback controller to reject the disturbances transferred through the common pivot timber by shaping the references to the VCM actuator and the total output of the dual stage system.