Improved control of atomic force microscope for high-speed image scanning

In this paper the design and experimental implementation of an observer based model predictive control (OMPC) scheme for accurate tracking and fast scanning of an atomic force microscope (AFM) is presented. The design of this controller is based on an identified model of the AFM piezoelectric tube (PZT) scanner. A Kalman filter is used to obtain full-state information in the presence of position sensor noise. To evaluate the performance improvement using the proposed control scheme an experimental comparison has been made with scanned images between the proposed controller and the existing AFM PI controller. The experimental results verify the efficacy of the proposed controller.