This article first reviews the position control of piezoelectric actuators, particularly charge-based sensorless systems, which often include a charge estimator as key component. The rest paper is about estimators for actuators. Two most recent/effective types these utilise either sensing capacitor (type I in this paper) or resistor II); latter (and newer) type broadly known digital estimator. ...

In this work, the problem of a curved functionally graded piezoelectric (FGP) actuator with sandwich structure under electrical and thermal loads is investigated. The middle layer in the sandwich structure is functionally graded with the piezoelectric coefficient g31 varying continuously along the radial direction of the curved actuator. Based on the theory of linear piezoelectricity, analytica...

 The eight-node solid-shell finite element models have been developed for the analysis of laminated composite pate/shell structures with piezoelectric actuators and sensors. To resolve the locking problems of the solid-shell elements in laminated materials and improve accuracy, the assumed natural strain method and hybrid stress method are employed. The nonlinear electric potential distributio...