A digital charge amplifier for hysteresis elimination in piezoelectric actuators

Abstract

Piezoelectric actuators are commonly used for nanopositioning due to their high resolution, low power consumption and wide operating frequency, but they suffer hysteresis, which affects linearity. In this paper, a novel digital charge amplifier is presented. Results show that hysteresis is reduced by 91% compared with a voltage amplifier, but over long operational periods the digital charge amplifier approach suffers displacement drift. A non-linear ARX model with long-term accuracy is used with a data fusion algorithm to remove the drift. Experimental results are presented.

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].…”

A review of charge methods for driving piezoelectric actuators

“…<10 Hz), charge and voltage drives are used jointly using filters and mathematical models developed with artificial intelligence techniques. This hybrid approach can almost vanish drift (Bazghaleh et al, 2013b). Surely, the utilised models and filters cannot be used in analogue circuits.…”

“…The first use of a digital charge amplifier for a piezoelectric actuator was presented in 2010 (Bazghaleh et al, 2010) due to inherent defects of analogue methods of charge drive. Analogue charge drivers, more or less, cause a considerable voltage drop which reduces the range of displacement.…”

“…Digital charge drive methods with wide operational bandwidth and very small voltage drops have been developed in past 4 years (Bazghaleh, 2014;Bazghaleh et al, 2013aBazghaleh et al, , 2013b. In a case reported in (Bazghaleh et al, 2013b), a digital drive method, an analogue capacitor-based sensing and an analogue capacitor insertion method were used to drive a piezoelectric stack to track a triangular position function within the range of 65 mm and frequency of 10 Hz. The digital solution not only provided an excellent tracking performance but also its voltage drop was only 1.7% and 10.9% of the drop in capacitor insertion and capacitorbased sensing methods, respectively.…”

“…This approach is commonly referred as voltage drive; (2) tuning the electrical charge applied on the actuator, commonly referred as charge drive (e.g. Bazghaleh et al, 2013b). Both approaches have been extensively used and are still under investigation (Clayton et al, 2009; Devasia et al, 2007; Gu et al, 2016; Moheimani, 2008).…”