Improving scanning speed of the AFMs with inversion-based feedforward control

This paper presents the design and experimental implementation of an inversion-based feedforward controller to achieve accurate tracking and fast scanning for an atomic force microscopy (AFM). The proposed controller reduces the tracking error by inverting the vibration dynamics and the hysteresis of the piezoelectric tube scanner (PTS). The hysteresis is compensated by directly constructing an inverse Prandtl-Ishlinskii model, while the vibration dynamics is suppressed by a zero magnitude error tracking controller. A comparison of the experimental images using the proposed controller and a dc-gain open-loop controller is given. The experimental results demonstrate the effectiveness of the proposed controller.