Gimbal and Slider Vertical Motion Characterization for DSA Servo-Mechanical Design Improvement

The PZT motor is a critical component for dual stage actuation (DSA) in hard disk drives. When voltage is applied to PZT motors, the suspension with the motors can provide slider off-track motion. Servo control has been focusing on the slider off-track motion because the control loop is designed based on the position error signal (PES) in the off-track direction. However, along with PZT off-track actuation, gimbal and slider vertical motion is inevitably introduced, which may increase head-disk interference risks and even cause lube moguls and ABS (air-bearing surface) wear. In this paper, we present an experimental methodology to investigate the relationship of slider vertical motion and DSA voltage injection.