Resonance-shifting integral resonant control scheme for increasing the positioning bandwidth of nanopositioners

Abstract

The performance of precision mechatronic systems is restricted by their first dominant resonant mode. Damping techniques have be employed to suppress this resonance peak and improve the performance. To increase the bandwidth of the system feed-forward techniques have been used but they can be very sensitive to modeling errors as well as loading effects. In this paper a simple frequency shifting controller is introduced and is combined with Integral Resonant Control (IRC). Using these controllers can increase the bandwidth of the system to a desired amount. Systems with colocated sensor-actuator pairs exhibit the interesting property of pole-zero interlacing. IRC exploits this property by changing the pole-zero interlacing to zero-pole interlacing. The unique phase response of this class of systems enables a simple integral feedback controller to add substantial damping.