System Identification and Control Design for a Tip Tilt Nanopositioning System

Abstract

This paper examines the system identification and control design for a tip tilt nanopositioning stage with an experimental case study based on the Queensgate NPS - θγ - 2M prototype nanopositioning stage that has two degrees of freedom (DOF) of tip tilting motion. The paper presents the multi-input multi-output (MIMO) position model and proposes a MIMO H-infinity control with loop shaping design. The control performance is compared with a benchmark SISO integral control. The H-infinity control has the advantage of increasing the response speed and improving the bandwidth while considering the whole multivariable model in the design scheme and maintaining the control robustness. The experiment results confirm that the MIMO H-infinity control has a better control performance in terms of the response time and bandwidth, compared with the benchmark SISO integral control.