Reducing Cross-Coupling in a Compliant XY Nanopositioner for Fast and Accurate Raster Scanning

A compliant XY nanopositioner is presented in this brief. The device is designed to have a very low cross-coupling between the X-and Y-axis. Despite this, during high-speed raster scans, the cross-coupling effect can not be ignored. In this brief, a H-infinity controller is designed and implemented to minimize the X-to-Y cross-coupling of the nanoscale positioning stage, particularly at its mechanical resonance frequencies. The controller is augmented with integral action to achieve accurate tracking, as well as sufficient damping. Raster scan results over an area of 10 mu m X 10 mu m with small positioning errors are demonstrated. High-speed accurate raster scans of up to 100 Hz, with nanoscale resolution are also illustrated.