Tracking of high frequency piecewise affine signals using impulsive control

Abstract

Most of the control work in nanopositioning relies on linear feedback control. However, there are inherent limitations on performance of linear feedback control systems, such as increased sensitivity to measurement noise in high-bandwidth control loops. In this paper, a novel non-linear control scheme is proposed which can improve tracking performance of a feedback control loop without increasing the linear bandwidth of the controller. This is achieved by impulsive changes of the controller states at discrete time instants. A remarkably simple impulsive control law is presented for a class of piecewise affine signals. The method is experimentally demonstrated using a silicon-based micro-electromechanical nanopositioner for precise tracking of triangular waveforms with frequency 100 Hz. © 2010 IFAC.