High-bandwidth control of a piezoelectric nanopositioning stage in the presence of plant uncertainties

Abstract

Inversion-based feedforward techniques have been known to deliver accurate tracking performance in the absence of plant parameter uncertainties. Piezoelectric stack actuated nanopositioning platforms are prone to variations in their system parameters such as resonance frequencies, due to changes in operating conditions like ambient temperature, humidity and loading. They also suffer from nonlinear effects of hysteresis, an inherent property of a piezoelectric actuator; charge actuation is applied to reduce the effects of hysteresis. In this work, we propose and test a technique that integrates a suitable feedback controller to reduce the effects of parameter uncertainties with the inversion-based feedforward technique. It is shown experimentally that the combination of damping, feedforward and charge actuation increases the tracking bandwidth of the platform from 310 to 1320 Hz.

A Survey of Modeling and Control of Piezoelectric Actuators

“…Another control scheme involving feedback and inverse model feedforward is shown in Figure 10 [97,138]. In this scheme, the feedback controller is a high gain controller used for nonlinear effect suppression such that the closed loop system has linear dynamics.…”

Piezoelectric Inertia Motors—A Critical Review of History, Concepts, Design, Applications, and Perspectives

“…This has been known since the early 1980s [230,231]. Charge-controlled driving of piezoelectric actuators is occasionally used in technical applications [232], but the realisation of simple and flexible charge amplifiers is not trivial, and continues to be an object of research [233][234][235][236]. Especially in low-frequency operation, most amplifier concepts show unacceptable drift ( [101]; [215] (p. 2); [233]), and partly require actuator-specific calibration [101].…”

Tracking of Triangular References Using Signal Transformation for Control of a Novel AFM Scanner Stage

“…There has been a significant effort to improve the tracking accuracy and speed of piezoelectric tube scanners using feedback control techniques. To track a fast triangular signal, high bandwidth closed-loop controllers have been implemented in many nanopositioning devices [19], [23], [24], [26], [28], [32]- [34]. However, the scanning speed is limited in feedback control systems due to hysteresis, thermal drift, sensor noise, uncertainty, and mechanical vibrations when piezoelectric tubes are used to follow non-smooth triangular trajectories [18].…”