An Operator-Based Controller Concept for Smart Piezo-Electric Stack Actuators
Part of the Solid Mechanics and Its Applications book series (SMIA, volume 89)
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Solid-state actuators based on piezoelectric materials are characterized by forces reaching the kilonewton range and reaction times on the order of microseconds. However, the displacements are low because the maximum strain amounts to 1.5.. 2 ‰ If they are used in micropositioning drives, the piezoelectric stack actuators are mainly driven with high voltages vt) to achieve the largest possible displacements st). In large-signal operation the actuator characteristic shows strong hysteresis and creep effects which can be regarded as undesired internal disturbances for the micropositioning process. Normally piezoelectric actuators are subsystems in an overlying mechanical structure. During the micropositioning process the mechanical structure reacts with a force f(t) against the piezoelectric transducer. This reaction force has a strong influence on the displacement and can therefore be regarded as an undesired external disturbance for the micropositioning process. Under normal operating conditions the displacement of the piezoelectric stack transducer can be seperated, at least in a first order approximation, into a creep and hysteretic voltage-dependent part described here by a scalar operator rΓ a and a linear force-dependent part characterised by the small-signal elasticity S
Equation (1) is the so-called operator-based actuator model of the piezoelectric stack transducer .
$$ s(t) = \Gamma _a [v](t) + S \cdot f(t). $$
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- 2.Kortendieck, H.: Entwicklung und Erprobung von Modellen zur Kriech-und Hysteresiskorrektur, VDI Verlag, Düsseldorf, 1993.Google Scholar
- 4.Krejci, P., Kuhnen, K.: Inverse Control of Systems with Hysteresis and Creep, submitted for publication in IEE Proceedings of Control Theory and Applications.Google Scholar
- 5.Kuhnen, K., Janocha H.: Compensation of the Creep and Hysteresis Effects of Piezoelectric Actuators with Inverse Systems, Proc. of the 6th Int. Conf. on New Actuators (1998), Messe Bremen GmbH, pp. 309–312.Google Scholar
- 6.Kuhnen, K., Janocha H.: Nutzung der inhärenten sensorischen Eigenschaften von piezoelektrischen Aktoren, tm-Technisches Messen 66 (1999), pp. 132–138.Google Scholar
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