压电模型参数辨识仿真实验

在对压电材料电气性能参数分析的基础之上,确立了以等效电路的电容、电感等参数作为压电材料性能指标的主要参数,离散化处理得到相应的差分数学模型,并对其进行了模型参数在线识别与最小二乘法MATLAB参数辨识仿真实验。实验结果表明:压电材料电气参数的辨识可以满足综合性能优化0.5%的设计要求。     

一种双足驱动直线超声波电动机的设计

设计了一种单边双足驱动的面内振动直线超声波电动机，其定子采用了一片铜板和八片压电陶瓷构成的复合结构，压电点陶瓷沿着厚度方向极化，对称安装在矩形铜板的两个表面上。建立了该电机的机电耦合动力学模型，通过仿真确定了驱动足的位置，并试验研究了电机的特性。     

New explicit formulas for the effective piezoelectric coefficients of binary 0-3 composites

The explicit formula for the effective dielectric constant of binary 0-3 composites (Poon and Shin, J. Mat. Sc. 39 (2004) 1277–1281) is extended into two explicit formulas for the prediction of the elastic properties of macroscopically isotropic 0-3 composites. By combining them with the explicit effective dielectric formula into a calculation scheme (Wong et al., J. Appl. Phys. 90 (2001) 4690), we obtained two new explicit formulas for the prediction of the d ₃₁ and d ₃₃ values for binary 0-3 piezoelectric composites. These two explicit formulas are applicable even when the inclusion volume fraction is high. Comparing with existing experimental data, they are found to fit more favorably than those predicted by Wong et al. and others. Also, being explicit makes these formulas much easier to be embedded into other effective property calculations for binary 0-3 composite materials.     

压电比例式阀门定位器的控制方法研究

压电式阀门定位器以其低耗气量以及低耗电量,被广泛应用于气动调节阀中.分析比例式压电阀的特性,在一定电压范围内,其进气口和排气口随着控制电压的不同而呈现出不同的开口大小.针对阀的这种特性,并考虑到气动执行机构的非线性,提出了一种控制算法,并且给出控制过程中所需参数的整定步骤与方法.利用dSPACE系统作为开发平台,并配合...     

基于ANSYS的磁致伸缩逆效应仿真方法研究

矩阵形式的压电与压磁方程及其各自在不同边界条件与变量下的转换关系在数学结构上具有一致性,即电学量与磁学量具有等效关系,由此提出通过ANSYS压电分析模块仿真超磁致伸缩材料(GMM)的磁致伸缩逆效应。GMM在恒载荷作用时,磁感应强度与偏置磁场强度成正比,GMM在恒偏置磁场下,载荷与磁感应强度具有相似的变化波形。理论与仿真分析表明,基于电学量与磁学量的等效,利用ANSYS压电耦合模块可在一定程度上分析磁致伸缩逆效应的相关性质,该方法对设计逆效应原理的GMM器件具有一定的辅助意义。     

Circuit analog of a beam and its application to multimodal vibration damping,using piezoelectric transducers

In this paper we solve the synthesis problem of finding a completely passive electric circuit analog to a vibrating beam. The synthesis problem is of interest when one wants to suppress beam mechanical vibrations by using distributed piezoelectric transduction. Indeed, an effective electromechanical energy transduction is guaranteed when the electric circuit (interconnecting the transducers' terminals) is resonant at all mechanical resonance frequencies and is able to mimic all the mechanical modal shapes. The designed electric circuit behaves as an electric controller of mechanical vibrations (i.e. an electric vibration damper) once suitably endowed with a set of resistors. Because of its completely passive nature, it does not require external power units and stands as an economical means of controlling vibrations. Copyright © 2004 John Wiley & Sons, Ltd.     

Partial Discharge Signal Detection by Piezoelectric Ceramic Sensor and The Signal Processing

Partial discharge (PD) in an insulator or on surface of defective conductor emits acoustic wave transmitting through an air or an insulator. The acoustic wave between 20 kHz and several hundred of kHz can be detected by piezoelectric ceramic sensor that converts the acoustic wave into an electrical signal. Piezoelectric ceramic sensor has either the wide resonant band or the local resonant band depending on the ceramic material or the various combinations of each different component in the manufacturing process. This paper presents the piezoelectric ceramic sensor with 0.95 PZT–0.05 PMNS that yields the piezoelectric properties of high k_p, high Q_m. It has the frequency characteristics of local resonant band, such that it can be applied to PD detection. We have demonstrated the properties of the proposed piezoelectric ceramic sensor by comparing with the conventional electrical PD detector. Quantitative analysis is accomplished by comparing the -q_max from a PD detector and the -v_max from the proposed sensor while -n distributions are the same for both the conventional phase-resolved PD analysis method and the proposed one.     

Design and Performance of Miniaturized Piezoelectric Step-Down Transformer

Piezoelectric transformers are expected to be small, thin and highly efficient, and which are attractive as a transformer with high power density for step down voltage. For these reasons, we have attempted to develop a step-down piezoelectric transformer for the miniaturized adaptor. we propose a piezoelectric transformer, operating in thickness extensional vibration mode for step-down voltage. This transformer consists of a multi-layered construction in the thickness direction. In order to develop the step-down piezoelectric transformers of 10 W class and turn ratio of 0.1 with high efficiency and miniaturization, the piezoelectric ceramics and piezoelectric transformer designs are estimated with a variety of characteristics. The basic composition of piezoelectric ceramics consists of ternary yPb(Zr_xTi_{1 – x})O₃–(1–y)Pb(Mn_1/3Nb_1/3Sb_1/3)O₃. In the piezoelectric characteristics evaluations, at y = 0.95 and x = 0.505, the electromechanical coupling factor(k_p) is 58%, piezoelectric strain constant (d₃₃) is 270 pC/N, mechanical quality factor(Q_m) is 1520, permittivity ( ₃₃^T/₀) is 1500, and Curie temperature is 350C. At y = 0.90 and x = 0.500, k_p is 56%, d₃₃ is 250 pC/N, Q_m is 1820, ₃₃^T/₀ is 1120, and Curie temperature is 290C. It shows the excellent properties at morphotropic phase boundary regions. PZT-PMNS ceramic may be available for high power piezoelectric devices such as piezoelectric transformers. The design of step-down piezoelectric transformers for adaptor proposes a multi-layer structure to overcome some structural defects of conventional piezoelectric transformers. In order to design piezoelectric transformers and analyze their performances, the finite element analysis and equivalent circuit analysis method are applied. The maximum peak of gain G as a first mode for thickness extensional vibration occurs near 0.85 MHz at load resistance of 10 . The peak of second mode at 1.7 MHz is 0.12 and the efficiency is 92%.     

一种多路压电驱动控制系统的研制及实验研究

针对粉体微输送的基本要求,提出一种基于DDS技术的多路压电控制系统的设计方案,系统包括了波形存储模块、基准频率产生模块、基准电压设置模块以及D/A输出模块等。系统可以实现多路信号的独立控制和输出,电压范围为0~100 V,频率范围为0~256 Hz,最后以羟基磷灰石和钛粉为例,进行了多路粉体微输送实验,结果表明所设计的系统完全满足多种粉体微输送的要求,并且具有非常高的稳定性和可靠性。     

柔性机械臂振动控制中的压电传感器故障诊断

压电传感器常被应用于结构的振动控制中,为了解决压电传感器故障给控制系统的带来的不稳定问题,根据压电柔性臂振动用压电传感片故障的特点,提出运用小波包变换和RBF神经网络的故障诊断方法。首先运用小波包分解和重构原理将传感器输出信号分解到不同频段中,提取每个频段的能量作为状态监测的特征向量,作为RBF网络的输入,然后利用最佳的RBF神经网络进行压电传感器故障分类。实验结果表明该方法具有良好的非以此线性跟踪能力,置信度达到90%,为后续振动容错控制研究奠定良好的基础。