A second-order controller for resonance damping and tracking control of nanopositioning systems

This paper presents a simple second-order controller that damps the resonance typical of piezoelectric nanopositioners and delivers good tracking performance. This method employs the Integral Resonant Control scheme (IRC) for damping the dominant resonant mode of the piezoelectric nanopositioner and uses an integral controller to achieve tracking performance. As disturbance rejection is a main concern in nanopositioning applications, the control scheme is tested for its disturbance rejection performance. It is seen that the control scheme has good disturbance rejection characteristics deeming it suitable for nanopositioning applications. To test the tracking performance, the system is made to track a 20 Hz triangular input at various integral gains. It is shown that improved tracking performance can be achieved at high gains with only a slight degradation in disturbance rejection performance at high frequencies.