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A significant difficulty associated with achieving high scan speeds in scanning probe microscopes is that the probe is required to scan the sample in a zig-zag (raster) pattern. The fast axis of the scanner is required to track a non-smooth signal that contains frequency components beyond its mechanical bandwidth. Therefore, fast raster scans lead to(More)
—In this paper, we design feedback controllers for lateral and transversal axes of an atomic force microscope (AFM) piezoelectric tube scanner. The controllers are constrained to keep the standard deviation of the measurement noise fed back to the displacement output around 0.13 nm. It is shown that the incorporation of appropriate inner loops provides(More)
Tracking of triangular or sawtooth waveforms is a major difficulty for achieving high-speed operation in many scanning applications such as scanning probe microscopy. Such non-smooth waveforms contain high order harmonics of the scan frequency that can excite mechanical resonant modes of the positioning system, limiting the scan range and bandwidth. Hence,(More)
— We demonstrate the application of internal model control for accurate tracking of spiral scan trajectories, where the reference signals are orthogonal sinusoids whose amplitudes linearly vary with time. The plant is a 2-D microelectromechan-ical system nanopositioner equipped with in situ differential electrothermal sensors and electrostatic actuators.(More)
In this research, a control scheme is proposed that provides a control law with lower complexity via an approximate feedback linearization methodology. This method uses the idea of exact linearization of an approximate imaginary robot with an inertia matrix that has zero Riemannian curvature. An optimal leastsquare procedure is presented for the selection(More)