Behavior Of Piezoelectric Actuators Research Articles

Characterization and RST control of a nonlinear piezoelectric actuator for a robotic hand

This paper presents the characterization, modeling, and control of piezoelectric actuators of a robotic system by considering the temperature effect. Besides the sensitivity to temperature variation, quite often the behavior of piezoelectric actuators is negatively affected by badly-damped vibrations and nonlinear phenomena such as strong hysteresis and creep. An analysis of the sensitivity of piezoelectric actuators to temperature variations (thermo-mechanical displacement) is first presented and the characterization results are discussed. The effect of the temperature mainly on the hysteresis loops, the creep, and vibrations is presented. Then, a temperature-dependent model of piezoelectric actuators is derived based on the study and characterization results obtained. Finally, the model of piezoelectric actuators obtained is used to design a robust RST (Regulation-Sensitivity-Tracking) controller to improve their behavior and achieve a good quality of positioning tasks. Experimental validation is given to demonstrate the efficacy of the presented modeling and control methods.

A fully dynamic model of a multi-layer piezoelectric actuator incorporating the power amplifier

The dynamic input–output characteristics of the multi-layer piezoelectric actuator (PA) are intrinsically rate-dependent and hysteresis. Meanwhile, aiming at the strong capacitive impedance of multi-layer PA, the power amplifier of the actuator can greatly affect the dynamic performances of the actuator. In this paper, a novel dynamic model that includes a model of the electric circuit providing voltage to the actuator, an inverse piezoelectric effect model describing the hysteresis and creep behavior of the actuator, and a mechanical model, in which the vibration characteristics of the multi-layer PA is described, is put forward. Validation experimental tests are conducted. Experimental results show that the proposed dynamic model can accurately predict the fully dynamic behavior of the multi-layer PA with different driving power.

Modelling of Mechanical Behaviour of High-Frequency Piezoelectric Actuators Using Bouc-Wen Model

AbstractThe paper presents application of a modified, symmetrical Bouc-Wen model to simulate the mechanical behaviour of high-frequency piezoelectric actuators (PAs). In order to identify parameters of the model, a two-step algorithm was developed. In its first stage, the mechanical parameters were identified by taking into account their bilinear variability and using a square input voltage waveform. In the second step, the hysteresis parameters were determined based on a periodic excitation. Additionally, in order to reduce the influence of measurement errors in determination of selected derivatives the continuum wavelet transform (CWT) and translation-rotation transformation (TRT) methods were applied. The results proved that the modified symmetrical Bouc-Wen model is able to describe the mechanical behaviour of PAs across a wide frequency range.

Systematic investigation and modeling of piezoelectric interaction with loading structures

ABSTRACTPiezoelectric actuators are spreading their applications in a variety of engineering systems, e.g., a compression mechanism with large force and high-precision motion systems. A systematic investigation of the dynamics of piezoelectric actuators that interact with loading structures is becoming requisite. This article discusses the dynamic model by merging constitutive equations of the piezoelectric material and the dynamics of loading structures. The dynamic behavior of piezoelectric actuators that interacts with loading structures depends on the stiffnesses of both entities. Two of the most common operating conditions of the actuator, based on its interaction with the loading structures, are classified and considered in this study: fixed–free and free–free conditions. The proposed dynamic models are subsequently validated on real mechanisms with satisfactory results. It is shown that the models are capable of capturing the dynamic interaction between the actuators and loading structures.

Heuristic modeling and inverse compensation of hysteresis in piezoelectric actuators based on time series similarity

Hysteresis behavior of piezoelectric actuators degrades the accuracy and performance of the micro or nano positioning stage. As a remedy to this problem, a hysteresis model and a compensator based on time series similarity are proposed in this article. To generate this dynamic hysteresis model, geometric and time scale similarity of output displacement time series of piezoelectric actuators are studied. Furthermore, to compensate for hysteresis behavior, an inverse model based on time series similarity and an inverse model–based feedforward compensator are proposed. This novel model–based compensator is validated against the Prandtl–Ishlinskii model–based one and is assessed for effectiveness and practicality.

Adaptive Sliding Mode Control Based on Duhem Model for Piezoelectric Actuators

ABSTRACTThe strong hysteresis nonlinearity extremely limits the positioning precision of piezoelectric actuators (PZAs). For the purpose of eliminating hysteresis effect and achieving high precise output displacement of PZAs, an adaptive sliding mode control method is proposed in this paper. The proposed hybrid control method is composed of an adaptive control method and a sliding mode control method. The simulations are conducted to validate the effectiveness of the proposed control method. The simulation results show that the proposed control method restrains hysteresis behaviour of PZAs efficiently and reduces maximum relative error to 0.57%. In contrast, the existing works lack efficient methods to deal with the uncertain parameters of the hysteresis model. The proposed control method in this paper can effectively solve the existing problems and improve the positioning precision of the control system of PZAs.

Modeling of nano piezoelectric actuator based on block matching algorithm with optimal block size

In order to model the hysteresis behavior of a nano piezoelectric actuator (PA) on nano scale in a real time system, a new hysteresis modeling method based on an improved sub-pixel blocking matching algorithm with an optimal block size is proposed in this paper. First, Preisach model is introduced to model the hysteresis behavior of a piezoelectric actuator. Then, a real time block matching algorithm is researched and its block size is optimized with a standard object. Finally, experiments are performed with respect to a nanometer movement platform system, and the results show the feasibility and validity of the sub-pixel estimation based block matching algorithm and its application in modeling the hysteresis behavior of PA.

Application of Support Vector Machines to the Tracking Control of Piezoelectric Actuators

In this paper, a hybrid approach associated the Preisach concept with support vector machines (SVM) is brought forward to identify and predict the nonlinear behavior of piezoelectric actuators (PA). Preisach concept is used to construct mesh nodes in the Preisach plane and determine the final output displacement of PA. SVM is trained based on the mesh nodes and provides favorable generalization ability in the Preisach plane. Experimental results validate the proposed method.

Analytical modelling of the electromechanical behaviour of surface-bonded piezoelectric actuators including the adhesive layer

The behaviour of a piezoelectric actuator is strongly affected by the bonding condition along the interface between the actuator and the host structure. The current paper represents an analytical study of the static effect of the mechanical and geometrical properties of the adhesive layer on the coupled electromechanical behaviour of a thin piezoceramic actuator bonded to an elastic medium. An actuator model with an imperfect adhesive bonding layer, which undergoes a shear deformation, is proposed to simulate the two dimensional electromechanical behaviour of the integrated system. Analytical solution of the problem is provided by solving the resulting integral equations in terms of the interfacial stress. Numerical simulation is conducted to study the effect of the bonding layer upon the actuation process. The effect of interfacial debonding on the response of the layered structure and on the interlaminar strain and stress transfer mechanisms is discussed.

Modeling of Piezoelectric Actuators Based on a New Rate-Independent Hysteresis Model

Accurate model representatives of piezoelectric actuators (PEAs) are important for both understanding the dynamic behaviors of PEAs and control scheme development. However, among the existing models, the most widely used classical Preisach hysteresis model are incapable of representing the commonly-encountered one-sided (non-negative voltage input range) hysteresis behaviors of PEAs. To solve this problem, a new rate-independent hysteresis model was developed for the one-sided hysteresis and then integrated with the models representative of creep and dynamics to form a single model for the PEAs. Experiments were carried out to validate the developed models.

A New One-Dimensional Rate-Based Phenomenological Model to Describe the Non-Linear Behaviour of Piezoelectric Actuators for Real-Time Applications

In this paper, a new rate-based phenomenological model of piezoelectric actuators for real-time applications is developed. This compact theoretical approach employs the Arrhenius equation for chemical reaction kinetics in order to describe the non-linear effect of domain switching. It needs only nine model parameters to account for the complete non-linearity of a piezoelectric actuator as well as the dependence of its non-linear effect on the electric field, the mechanical stress, and the temperature. This general validity for a wide range of operation conditions, which is based on a simplified description of the real behaviour, is the optimum prerequisite for a technically inexpensive control loop strategy for fast piezoelectric actuators as they are employed in state-of-the-art gasoline and diesel injectors for combustion engines. Moreover, other interfering physical effects, such as ageing, which may cause an injector's dosing function to deteriorate severely can be tackled by making use of this approach in electronic control units. All this is possible because the extremely compact theoretical formulation with a compact set of parameters does not need access to complex characteristic diagrams so that the most essential requirements of an automotive control unit such as a minimum computation time and a modest requirement of storage space can be fulfilled.

The dynamic behavior of a surface-bonded piezoelectric actuator with a bonding layer

The performance of smart structures depends on the dynamic electromechanical behavior of piezoelectric actuators and the bonding condition along the interface, which connects the actuators and the host structures. This paper provides a theoretical study of the influence of material parameters of the bonding layer on the coupled electromechanical characteristics of piezoelectric actuators, which are subjected to high frequency electric loads. A one-dimensional actuator model with a bonding layer, which undergoes a shear deformation, is proposed. Analytical solutions based on the integral equation method are provided. Detailed numerical simulation is conducted to evaluate the effect of the bonding layer under different loading frequencies. The results indicate that the properties of the bonding layer, the loading frequency, the material combination and the geometry of the actuator have a significant effect on the load transfer between the actuator and the host medium.

A Low-Cost Experimental Setup to Characterize Piezoelectric Cantilever Bimorphs

Hysteresis is a common phenomenon in nonlinear systems. Piezoelectric bimorphs show hysteretic behavior when operating as actuators. Tools that produce the characterization of these devices are available; they use high-cost setups that measure deformations with resolutions on the order of nanometers. In this paper, a new low-cost experimental setup that uses coupled infrared detectors to investigate the behavior of piezoelectric actuators is discussed. The tool, providing deformation measurements with a resolution on the order of 10 , is intended to produce a rough estimation of the device behavior and is of interest for research and educational purposes. Low cost, easy reproducibility in research and educational laboratories, a contactless measurement strategy, an inset calibration facility, and a suitable user interface are the main features of the tool developed. Notes on the uncertainty introduced by the tool when estimating bimorph deformations are given. Moreover, a case study that concerns the characterization of a piezoelectric bimorph actuator is discussed to illustrate the performance of the system developed in a real case.

The Characteristic Analysis of a Piezoelectric Actuator for Valveless Micropumps

The behavior of a circular piezoelectric actuator for volumetric micropump has been investigated by using theoretical and finite element analyses. A modified theoretical model was developed to predict the behavior of a piezoelectric actuator induced by the applied voltage. The theoretical results for the diaphragm deflection were in good agreement with the results from numerical simulation. Based on the theoretical analysis, the effects of several important parameters on actuation performance have been investigated. These parameters include the dimensions and mechanical properties of the piezoelectric disk, bonding layer and elastic diaphragm materials. Consequently, it is thought that above theoretical model might be employed as a tool for design and optimization of the piezoelectric actuator for micropump application.