压电陶瓷执行器Preisach模型的分类排序实现

通过实验研究了压电陶瓷执行器迟滞的擦除特性和一致特性,提出了一种新的分类排序实现方法,改善了经典Preisach模型在非单调极值输入信号下描述迟滞输入输出特性的能力,消除了传统Preisach模型实现形式对输入信号的限制条件。实验表明,这种Preisach模型分类排序实现方法能有效地预测压电陶瓷执行器的位移,提高了迟滞建模精度。     

压电驱动器建模与控制技术研究

该文对压电驱动器建模与控制技术进行了研究。通过二阶系统描述了压电驱动器的线性动态特性。基于Preisach迟滞模型,提出了全新的简化模型,避免了Preisach模型中复杂的双重积分运算。通过前馈与反馈控制技术相结合,为压电驱动器设计了一个综合控制器。在前馈控制器中,通过Preisach模型描述逆迟滞环,有效解决了Preisach模型不可逆的问题。通过比例、积分、微分(PID)反馈控制器,有效提高了系统鲁棒性,并有效补偿了前馈控制器中模型不精确带来的误差。最终,通过实验分别验证了模型的有效性及控制器的控制作用。     

压电陶瓷迟滞逆模型的前馈PID控制

为减小压带陶瓷迟滞特性对系统跟踪精度的影响,在Preisach模型的基础上对压电陶瓷迟滞性进行建模。借助Matlab软件对实验数据进行拟合和采用逆控制思想,在迟滞逆模型的基础上提出前馈PID(即比例、积分、微分)控制算法。实验结果表明,压电陶瓷最大迟滞性控制在2.2%内,输入、输出具有较好的线性关系,带前馈的PID控制具有良好的控制性能。     

一种改进Preisach模型数值实现方法

探究描述压电陶瓷迟滞特性的传统Preisach数值实现方法的弊端,针对这种数值实现不具有擦除特性,提出一种具有擦除特性的改进Preisach数值实现方法,并描述其详细原理与实现过程,最后进行相关实验研究。实验结果表明,该文提出的具有擦除特性的改进Preisach数值实现方法在复杂加载过程中能相对精确地计算压电陶瓷输出位移,提高了迟滞建模精度,具有更广泛的应用范围。     

压电驱动器迟滞特性的Preisach模型研究

压电驱动器的迟滞特性是影响其位移输出精度的主要因素。该文采用改进的Preisach模型对压电驱动器的迟滞特性进行建模，并进行了相应的实验研究。实验结果表明该模型可以很好地预测压电驱动器在经过一定的控制电压序列以后的位移输出值．能够有效地降低迟滞特性对压电驱动器位移输出精度的影响。     

磁致伸缩作动器的建模与控制研究

Preisach算子是一种适用于迟滞特性建模的通用数学工具。利用该算子建立了磁致伸缩作动器的模型，并推导了相应的数值计算公式。对于作动器的轨迹跟踪控制问题，提出了一种基于模型近似线性化的前馈控制方法。实验结果表明该模型可以较好地反映作动器的迟滞特性，利用其数值计算方法求解作动器的输出有较高的精度，满行程位移误差达1．2％；所提出的控制方法有较理想的控制效果，位置控制误差约为3．4％。     

基于PI逆模型的快速微摆反射镜的开环控制

由压电陶瓷驱动器构成的快速微摆反射镜平台存在迟滞特性,影响了对快速微摆反射镜的控制。为了能够有效的对快速微摆反射镜进行控制,采用基于PI逆模型的开环控制方法。首先,采用PI模型对快速微摆反射镜平台的迟滞特性建立数学模型,通过最小二乘法辨识PI模型的参数;其次,基于PI模型的可逆性,求解PI逆模型参数;最后,验证基于PI逆模型的开环控制方法的有效性。根据轨迹跟踪实验得到的数据,在正弦波轨迹输入信号下的均方根误差为1.23%,最大误差为2.45%;在三角波轨迹输入信号下的均方根误差为1.3%,最大误差为2.37%。证明了基于PI逆模型的开环控制方法是可行的,能够有效地控制快速微摆反射镜。     

基于神经网络的精密定位工作台建模方法

压电陶瓷的迟滞非线性使得难以用传统方法获取精确而且实时的数学模型,为了提高精密定位工作台的模型精度,提出了一种基于神经网络的建模方法.分析了定位系统的结构和特性,利用神经网络的自学习能力,建立起能够在线调整的网络模型.在最大行程80μm范围内进行了实验测试,与Preisach模型相比,网络模型的平均误差和最大误差均有所减小,与实际工作台有着更好的拟合性.     

压电陶瓷作动器的改进Duhem迟滞建模

针对压电陶瓷作动器自身存在的迟滞特性,且在高频信号下迟滞现象更严重的问题,该文提出了一种基于单输入单输出关系建立的改进Duhem模型.根据实验测得压电陶瓷作动器输入输出数据,采用差分进化算法辨识得到作动器的参数化模型,并通过与经典Duhem模型进行对比,验证了该模型的有效性.实验结果表明,与经典Duhem模型相比,改进...     

压电陶瓷驱动微进给刀架的迟滞建模

以对称式微位移缩小机构和柔性铰链相结合,压电陶瓷驱动的微进给刀架可实现精密加工,但刀架的迟滞特性影响其定位精度。该文根据非线性Preisach模型的理论知识及压电陶瓷驱动微进给刀架的电压位移特性,将模型进行修改后得到刀架迟滞特性的数学模型,并对数学模型式进行离散化处理。实验结果表明,改进后的迟滞模型形式简单,数据采集简便,模型描述精确,能较好地实现压电驱动微进给刀架的迟滞建模,提高了迟滞模型的实用性。为提高压电陶瓷驱动微进给刀架的定位精度,实现精密控制打下基础。     

Tracking control of a piezoceramic actuator with hysteresis compensation using inverse Preisach model

This paper presents the classical Preisach hysteresis modeling and tracking control of a curved pre-stressed piezoceramic patch actuator system with severe hysteresis. The actuator is also flexible with very small inherent damping. It has potential applications in active antennas. A series of tests are conducted to study the hysteresis properties of the piezoceramic actuator system. The numerical expressions of the classical Preisach model for different input variations are presented. The classical Preisach model is applied to simulate the static hysteresis behavior of the system. Higher order hysteresis reversal curves predicted by the classical Preisach model are verified experimentally. The good agreement found between the measured and predicted curves showed that the classical Preisach model is an effective mean for modeling the hysteresis of the piezoceramic actuator system. Subsequently, the inverse classical Preisach model is established and applied to cancel the hysteresis the piezoceramic actuator system for the real-time microposition tracking control. In order to improve the control accuracy and to increase damping of the actuator system, a cascaded PD/lead-lag feedback controller is designed with consideration of the dynamics of the actuator. In the experiments, two cases are considered, control with major loop hysteresis compensation, and control with minor loop hysteresis compensation. Experimental results show that RMS tracking errors are reduced by 50% to 70% if the hysteresis compensation is added in the feedforward path in both cases. Therefore, hysteresis compensation with the feedback controller greatly improves the tracking control accuracy of the piezoceramic actuator.     

Novel models for one-sided hysteresis of piezoelectric actuators

The hysteretic behavior of a plant with a non-negative input, referred to as one-sided hysteresis, is characterized by an initial ascending curve and hysteresis loops. It is observed that the widely-used classical Preisach hysteresis model and its modifications cannot represent such one-sided hysteresis due to the limitation of the Preisach hysteresis operator. To address this issue, a novel hysteresis operator modified from the Preisach hysteresis operator is proposed in this study and on this basis, a rate-independent hysteresis model and a rate-dependent hysteresis model are developed with methods to estimate their parameters. An algorithm to invert the rate-independent hysteresis model and its application to tracking control are also presented. The models and control schemes developed were verified experimentally on a commercially-available piezoelectric actuator. The results obtained show that the models developed are promising to represent the one-sided hysteresis of the piezoelectric actuator and that the inverting algorithm of the rate-independent hysteresis model is effective as applied to the tracking control of piezoelectric actuators.     

Hysteresis compensation in electromagnetic actuators throughPreisach model inversion

In this paper, the classical Preisach independent domain model is used to capture the essential characteristics of hysteresis nonlinearity in electromagnetic (EM) actuators made of soft ferromagnetic material. Experimental results demonstrate its ability to accurately model electromagnetic hysteresis for variations in input current, airgap, and orientation. The Preisach model is then inverted and incorporated in an open-loop control strategy that regulates the EM actuator and compensates for hysteretic effects; hysteresis-free regulation of the EM actuator is obtained, for variations in input current, airgap, and orientation. Hysteresis is also effectively compensated for desired force trajectories of frequencies up to 100 Hz. Thus, the experimental results demonstrate consistent performance of the open-loop control strategy based on Preisach model inversion, in satisfactorily regulating the output of the EM actuator to the desired trajectories     

Parameterized hysteresis model for high-temperature superconductors

High-temperature superconductors (HTS) exhibit hysteresis, which is the main cause for losses in the subcritical domain. This behavior is well predicted by Bean's critical-state model, which is a subset of the classical Preisach model. We present a parameterized Preisach model that describes the hysteresis of HTS specimens in self-field, where the parameters are identified from electrical lock-in (loss) measurements. That means the model can be used independent of geometry, number of filaments, and other physical measures as long as Bean's model applies. An advantage of the model is that it can predict outputs (flux, voltage) and losses for arbitrary input currents once the HTS has been characterized from measurements. We have further derived exact models for the hysteretic losses in strip and elliptic geometry strips, where the energy losses were calculated by Norris     

On the classical Preisach model for hysteresis in piezoceramic actuators

A classical Preisach model [Mathematical Models of Hysteresis, Springer, New York, 1991] is developed using a piezoceramic actuator in a stacked form. The classical Preisach model is shown to offer excellent modeling accuracy when the actuator is not subject to any load and is subject to an excitation voltage signal at a low frequency. The accuracy of the Preisach model is shown to increasingly deteriorate as the load being applied to the piezoceramic actuator is increased or the range of frequencies contained in the voltage excitation signal gets wider. The classical Preisach model remains, though, a good model for hysteresis in piezoceramic actuators in applications where the load fluctuation is relatively small and the range of frequencies of the voltage excitation is limited.     

Modeling of piezo actuator’s nonlinear and frequency dependent dynamics

To facilitate on-line identification and implementation of a piezoelectric actuator model for precision machining, this paper describes a hybrid hysteresis model integrating the classical Preisach model and a neural network. The incorporation of a neural network enables on-line model identification from operating data of a piezo (a great contrast to the tedious calibration process required by the classical Preisach model). The model is then extended to describe a piezo actuator’s frequency dependent behavior which is not possible for the classical model. Experimental results confirmed the accuracy of both models and the superiority of the extended one.     

Design of hysteresis-compensating iterative learning control for piezo-positioners: Application to atomic force microscopes

This article addresses hysteresis-caused positioning error in piezo-based systems, such as atomic force microscopes. First, we present the design of an iterative learning control algorithm based on the Preisach hysteresis model. For a given output bound, we determine the algorithm’s rate of convergence. Second, we compensate for creep in the piezo system to determine a hysteresis model, and then the parameters of the model are used to find an appropriate value of the iteration gain such that convergence of the control algorithm is guaranteed. Finally, we demonstrate the efficacy of the approach, to achieve high-precision positioning, by applying the control algorithm to an experimental atomic force microscope system. Results show that iterative learning control can achieve substantial reduction of hysteresis-caused error, e.g., the tracking error is reduced to 0.24% of the total displacement range, which is approximately the noise level of the sensor measurement.