Tracking Control of a Novel AFM Scanner using Signal Transformation Method

In this paper, we design feedback controllers for lateral and transversal axes of an AFM piezoelectric tube scanner. The controllers are constrained to keep the standard deviation of the measurement noise fed back to the displacement output around 0.1nm. It is shown that the incorporation of appropriate inner loops provides disturbance rejection capabilities and robustness against DC gain uncertainties, two requirements for satisfactory operation of signal transformation method. Simulations and experiments show significant improvement of steady-state tracking error with signal transformation, while limiting the projected measurement noise.