Micropositioning Control for an Amplified Magnetostrictive-Actuated Device

In this article, an amplified giant magnetostrictive actuator (GMA) device is developed, and an adaptive feedforward controller is proposed to realize micropositioning integrated with proportional-integral (PI) feedback. Micro-positioners are employed in many precision engineering fields. However the trade-off between the accuracy and the stroke of micropositioners, the efficacy and the efficiency of closed-loop control strategies still need to be further studied and improved. Therefore, twofold are conducted in this paper: first, for the purpose of fulfilling large-stroke micromotion, the GMA with a flexure-based amplified mechanism is developed; second, an adaptive feedforward controller, integrated with PI feedback controller, is utilized to compensate the micropositioner. Finite-element-analysis shows the amplified GMA satisfies design objective, and closed-loop tracking experiments demonstrate the effectiveness of the proposed control approach.