Nanopositioning system with force feedback for high-performance tracking and vibration control

In this study, the actuator load force of a nanopositioning stage is utilized as a feedback variable to achieve both tracking and damping. The transfer function from the applied actuator voltage to the measured load force exhibits a zero-pole ordering that greatly simplifies the design and implementation of a tracking and damping controller. Exceptional tracking and damping performance can be achieved with a simple integral controller. Other outstanding characteristics include guaranteed stability and insensitivity to changes in resonance frequency. Experimental results on a high-speed nanopositioner demonstrate an increase in the closed-loop bandwidth from 210 Hz (with an integral controller) to 2.07 kHz (with a force-feedback control). Gain margin is simultaneously improved from 5 dB to infinity.