Data-Driven Feedforward Control Design and Input Shaping Techniques for Multi Actuator Drives

Abstract

The multi actuator drive technology was unveiled by Seagate in December 2017, a breakthrough that can almost double the data performance of the future generation hard disk drives. This technology will equip drives with dual actuators operating on the same pivot point. Each actuator will control half of the drive’s arms. Since two actuators operate independently on the same pivot timber, the control forces and torques generated by one actuator can affect the operation of the other actuator. We will have a scenario when one actuator is track seeking and the other actuator is in the track following mode. The track seeking actuator will impart vibration disturbances to the track following actuator. Previously, we presented a single-input single-output (SISO) data-driven feedforward control design method (Shah and Horowitz, 2019. “Active Vibration Rejection in Multi Actuator Drives: Data Driven Approach,” Dynamic Systems and Control Conference, Vol. 3) to obtain feedforward controllers for the voice coil motor (VCM) and the micro actuator sequentially. The design was based on multiple frequency response measurements of the actuators. In this paper, first, we present a single-input multi-output (SIMO) data-driven feedforward control design technique to simultaneously obtain feedforward controllers for the VCM and the micro actuator. This methodology will obtain a common controller for multiple drives. We will compare the performance of this algorithm with the sequential SISO design technique (Shah and Horowitz, 2019. “Active Vibration Rejection in Multi Actuator Drives: Data Driven Approach,” Dynamic Systems and Control Conference, Vol. 3). Second, we present an add-on input shaping technique to suppress the residual vibration.