Resonant controller design for a piezoelectric tube scanner: A mixed negative-imaginary and small-gain approach

This brief presents the design and implementation of a single-input single-output and a multiple-input multiple-output resonant controller to damp the first resonant mode of a piezoelectric tube scanner of an atomic force microscope. The design of the controller is based on a mixed negative-imaginary and small-gain approach and the controller structure is chosen such that closed-loop stability is guaranteed. Experimental results are presented to demonstrate the effectiveness of the resonant controller.