压电陶瓷驱动系统及控制方法研究

给出了一种压电陶瓷驱动系统的控制方法,利用VB中的Timer控件和压电陶瓷电源的DLL动态连接库函数,实现了控制电压的实时可编程输出。针对压电陶瓷驱动器的非线性和迟滞特性,应用MATLAB分别拟合出压电陶瓷驱动器在往返行程中电压与位移值的多项式拟合曲线,得到了电压与位移的关系式,为进一步修正和减少非线性及迟滞误差的影响、提高系统的定位精度,提供了分析的依据。     

压电陶瓷微位移机构系统精密驱动电源的研究

本文介绍了压电陶瓷的微位移机构系统。并对机构系统的精密驱动电源进行了深入的研究、提出了一种新型的微机控制的开关式精密驱动电源。该电源克服了传统的串联型晶体管稳压电源功耗大、效率低和散热性差等缺点、实现了输入电压为０～５Ｖ时、输出电压在０～３００Ｖ范围内连续可调．具有５０ｍＶ的高分辨率和较为理想的静特性、其线性相关系数为０．９９９８，纹波电压小于±１０ｍＶ，电源在３．８ＫＨｚ范围内频响特性很好。     

压电陶瓷微位移驱动技术研究

精密异形非圆回转曲面的加工是精密加工中很重要的内容,微位移驱动技术是其中的关键技术.目前,微位移驱动元件种类很多,从控制精度和可操作性分析,压电陶瓷驱动有其独特的优点,但它的输出位移小,而且对于一定的驱动电源,输出幅度与输出频率负相关,这在很大程度上制约了它在高频响较大幅度位移输出场合的应用.为此首先对压电陶瓷的静、动态驱动特性进行了分析,并就特定PZT(Piezoelectric translator)进行了试验,在此基础上说明了该类微位移驱动有效的加工范围和改善其输出特性的措施,并提出了一种在较高频率下输出较大位移的方法,通过对系统进行数学建模进行了分析讨论,指出了其应用前景.     

压电陶瓷驱动器的迟滞非线性规律

探究压电陶瓷的迟滞非线性规律,为进一步修正迟滞非线性提供参考依据和理论基础。通过实验测量得到迟滞模型并对实验数据分析,拟合出上升轨迹的修正直线,求出其在相同位移下与上升、下降轨迹的电压差作为补偿电压,发现两条轨迹采样点上的输入电压与补偿电压满足近似多项式关系;分别选定5,10和15V不同步长进行驱动实验。实验结果:上升轨迹(下降轨迹)多项式参数R-square=0.999 2(0.999 9),RMSE=0.083(0.080 86);R-square=0.999 7(0.999 9),RMSE=0.057 39(0.094 99);R-square=0.995 2(0.999 8),RMSE=0.291 6(0.165 5)。实验结论:两条轨迹的R-square近似为1,RMSE较接近0,重复性误差在1.13%～2.63%,输入电压与补偿电压满足近似多项式关系,拟合程度和匹配性较高,且重复性较好,具有可预测性,从而为进一步修正压电陶瓷驱动器的迟滞非线性提供了参考依据和理论基础。     

WTYD型压电陶瓷微位移器的迟滞特性模拟

为了模拟WTYD型压电陶瓷微位移器的输出位移与驱动电压之间的迟滞曲线,本文通过采用Bouc-Wen模型模拟迟滞分量提出了一种表征WTYD型压电陶瓷微位移器的输出位移与驱动电压之间的迟滞关系的Bouc-Wen模型并建立了相应的参数辨识方法。为了验证Bouc-Wen模型及其相应的参数辨识方法的有效性,建立了相应的实验装置并对模型进行了实验验证。研究结果表明,本文提出并研究的WTYD型压电陶瓷微位移器的Bouc-Wen模型及相应的参数辨识方法能较好地模拟WTYD型压电陶瓷微位移器的迟滞特性。     

压电陶瓷微位移驱动技术的研究

精密异形非圆回转曲面的加工是精密加工中很重要的内容，微位移驱动技术是其中的关键技术。压电陶瓷驱动控制精度高、可操作性强，但它的输出位移小，而且对于一定的驱动电源．输出幅度与输出频率负相关，制约了它在高频响、较大幅度位移输出场合中的应用。文章首先对压电陶瓷的静、动态驱动特性进行了分析，并就特定PZT(Piezoelectric Translator)进行了实验．在此基础上提出了该类微位移驱动有效的加工范围和改善其输出特性的措施，提出了一种在较高频率下输出较大位移的方法。     

压电陶瓷微位移驱动器建模与控制

考虑利用白光干涉仪进行表面三维形貌测量时压电陶瓷(PZT)的蠕变效应对微位移驱动器位移精度的影响,提出了一种沿参考镜光轴方向提高该驱动器位移精度的方法.系统研究了该驱动器的位移检测回路、PID闭环控制以及蠕变补偿控制;利用光电位置传感器和光学杠杆调节位移检测回路,将压电陶瓷驱动器微位移反馈至控制系统,建立PID闭环控制.充分考虑了PZT蠕变特性对测量过程的影响,建立了"电压蠕变"补偿模型,实现了基于PID闭环控制与蠕变补偿控制相结合的复合控制方法.利用XL-80激光干涉仪测量压电陶瓷驱动器在PID闭环控制和复合控制二种情况下的微位移,实验结果显示前者位移误差为0.007 μm,后者位移误差为0.005 μm.结果表明该方法可有效克服压电陶瓷迟滞非线性和蠕变对测量结果的影响,满足表面三维形貌测量的高精度要求.     

WTYD型压电陶瓷微位移器的迟滞特性建模与实验验证

为了模拟WTYD型压电陶瓷微位移器的输出位移与驱动电压之间的迟滞曲线,通过采用Bouc-Wen模型模拟迟滞分量,提出了一种表征WTYD型压电陶瓷微位移器的输出位移与驱动电压之间迟滞关系的Bouc-Wen模型并建立了相应的参数辨识方法。为了验证Bouc-Wen模型及其相应的参数辨识方法的有效性,建立了相应的实验装置并对模型进行了实验验证。研究结果表明,Bouc-Wen模型的最大绝对误差为3.78μm,最大相对误差为5.79%,表明Bouc-Wen模型及相应的参数辨识方法能较好地模拟WTYD型压电陶瓷微位移器的迟滞特性。     

压电陶瓷驱动器的复合控制方法研究

针对压电陶瓷驱动器中的迟滞非线性特性,提出一种提高压电陶瓷执行器定位精度的复合控制方法。建立了非等间隔阈值的Prandtl-Ishilinskii(PI)迟滞模型,通过自适应差分进化算法进行系统辨识,求取参数并建立逆模型。考虑到压电陶瓷迟滞非线性特性随输入信号频率变化的特点,采用融合PI逆模型前馈控制与滑模控制的复合控制方法用于压电陶瓷的精密驱动。实验结果表明,相比逆模型前馈和PID结合的复合控制方法,采用逆模型前馈和滑模复合控制方法,平均误差下降了0.0300μm,均方根误差下降了0.0346μm,能有效克服压电陶瓷迟滞非线性,提高系统跟踪性能。     

压电陶瓷执行器迟滞的滑模逆补偿控制

为了降低迟滞特性对压电陶瓷执行器的影响,研究了基于Preisach逆补偿的滑模控制策略.首先,利用分类排序方法在控制平台上实现了迟滞的Preisach逆模型;然后,将其串联到压电陶瓷执行器前用于抵消迟滞非线性.考虑到迟滞逆补偿的非完全抵消、模型参数的不确定性以及扰动等问题,设计了一种分段边界层滑模控制律.最后,为了验证...     

Modeling of piezoelectric actuator for compensation and controller design

This work proposes a novel method for describing the hysteretic non-linearity of a piezoelectric actuator. The hysteresis behavior of piezoelectric actuators, including the minor loop trajectory and the residual displacement near zero input, are modeled by a set of hysteresis operators, including a gain and an input-dependent lag, as well as the parameter scheduling method. A hysteresis model, using the identified parameters, and containing only the dominant hysteresis operator, is presented herein. Based upon a simplified hysteresis model, tracking is controlled to reduce the non-linear effects in the characteristics of the piezoelectric actuator. A proportional-integral (PI) controller, with inverse model feed-forward, suppresses the tracking error to within ±1% full span range (FSR) of the actuator, noticeably improving the tracking performance of the piezoelectric actuator.     

压电陶瓷执行器迟滞与非线性成因分析

从微观上系统分析了电致伸缩效应、逆压电效应和铁电效应的位移机理,表明:三种效应的位移机理是根本不同的;压电陶瓷执行器的位移主要是由逆压电效应、铁电效应所引起的,电致伸缩效应对位移的贡献极其微弱,可以忽略不计;单纯的逆压电效应是线性的,而铁电效应则是迟滞非线性的.指出了非180°电畴转向与转向的不完全可逆,分别是造成压电陶瓷执行器非线性和迟滞的根本原因.通过实验研究了驱动电压幅值、驱动电压频率、驱动循环次数及晶片厚度对压电陶瓷执行器迟滞和非线性的影响.     

Modeling of hysteresis in piezoelectric actuators using neural networks

For the application of neural networks to the approximation of hysteresis which is characterized of multi-valued mapping and non-smooth nonlinearities, a novel modeling technique based on a transformation of one-to-one mapping is proposed in this paper. In this method, a special hysteretic operator is introduced to describe the change tendency of the hysteresis with regard to its input. Then an expanded input space is constructed for hysteresis with the introduction of such hysteretic operator, on which the multi-valued hysteresis is decomposed into a one-to-one mapping. Thus, neural networks model for hysteresis is derived, avoiding the calculation of the gradient of hysteresis. Subsequently, for approximation of rate-dependent hysteresis in piezoelectric actuators which is caused by the dynamic voltage excitations, a hybrid model, i.e. the dynamic extension of the proposed neural hysteresis submodel is developed. In the model, a linear dynamic block is introduced in series with the proposed neural model to allow for rate-dependent dynamics of the piezoelectric actuator simultaneously. Also the corresponding optimization algorithm by use of the modified Levenberg–Marquarqt (MLM) method is given. Finally, the experimental validation results of applying both the proposed neural hysteresis model and hybrid model to a piezoelectric actuator are presented.     

Output feedback integral control of piezoelectric actuators considering hysteresis

In this paper, output feedback integral control of piezoelectric actuators is considered with respect to the hysteresis effect. The linear dynamics of the piezoelectric actuator is modeled as a linear state space system with an input nonlinearity that considers the hysteresis effect. A proof of the Lyapunov stability of the system with integral control is presented, and a method for deriving the upper bound for the regulating gain is shown. A simple example is used to illustrate the approach, and then the approach is applied for tracking a step signal with an experimental single-axis piezoelectric actuator to verify that the system is stable.     

尺蠖型压电驱动器的闭环控制研究

针对尺蠖型压电驱动器的输出特性,提出利用驱动电压与输出位移分段线性拟合曲线、逐步“搜索”驱动电压值,从而逼近目标位置的闭环控制方法,分析了控制方法的可行性。针对该方法,构建了闭环控制试验系统,对该方法进行了验证,试验结果表明：采用该方法可以实现对尺蠖型压电驱动器的闭环精确控制,相比于开环工作而言定位精度提高了14.4%,该方法具有控制精度较高、响应迅速等优点。     

基于压电驱动的细胞微量注射装置的研究

提出了由压电驱动带动的注射微动平台和电机带动的细胞微载台来构成细胞药物微量注射的机械结构与控制系统。而且也提出了利用压电陶瓷的微位移特性构造了和目前的微量注射针完全不同的微量注射针结构与控制系统,这个压电微量注射针的驱动和注射动作全部由压电驱动器来完成;利用压电陶瓷的微位移和施加在压电陶瓷上的电压在微小位移情况下的线性关系实现了细胞注射系统的精确微定量注射。     

Application of cat's-eye retroreflector in micro-displacement measurement

The performance of a cat's-eye retroreflector in interferometric micro-displacement measurements is discussed. Based on paraxial calculations, approximate equations of the wavefront distortion and the measurement error caused by the displacement itself are derived. The capability for nanometer scale error compensation is suggested.     

Dynamic analysis of laminated composite plates with piezoelectric sensor/actuator patches using the FSDT mesh-free method

This paper investigates the active control of laminated composite plates with piezoelectric sensor/actuator patches using an efficient mesh-free method, i.e. the element-free Galerkin (EFG) method. The formulation of the problem is based on the first-order shear deformation plate theory (FSDT) and the principle of virtual displacements. A simple control algorithm coupling the direct and converse piezoelectric effect is used to control the dynamic response of the laminate plate with distributed sensor/actuator patches through a closed control loop. Several example problems are studied to show the influence of stacking sequence and position of sensor/actuator patches on the dynamic responses of the laminate plate. These simulations provide us with the best location of the sensor/actuator patches for active control of the laminate plate.     

压电驱动器记忆特性迟滞非线性建模

考虑压电驱动器固有的迟滞特性对驱动器定位精度的影响,提出了一种精确描述压电驱动器迟滞非线性特性的建模方法.根据迟滞曲线的运动规律,并且考虑迟滞曲线的记忆更新特性,新的迟滞数学模型修正了单纯采用抛物线拟合时的建模误差.为了验证模型的有效性,以PST150/7/40VS12型压电陶瓷驱动器为例进行了试验研究.研究显示,采用抛物线迟滞模型对一阶反转输入信号进行预测时,最大误差为0.141 3 μm,均方误差为0.060 4 μm,对复杂信号模型预测的最大误差为1.396 0 μm,均方误差为0.856 6 μm;采用修正后的模型对文中复杂信号建模时,最大误差为0.237 0 μm,均方误差为0.09 μm.实验结果表明,修正后的模型不仅能够满足迟滞曲线的运动规律,还能够满足迟滞非线性的记忆更新特性,可以比较精确地描述复杂输人信号下的迟滞非线性特性.     

Modeling nonlinear behavior in a piezoelectric actuator

A piezoelectric tube actuator is employed as a sample positioning device in Nanocut, a cutting instrument conceived to study the mechanics of nanometric cutting. Extension of functionality of the instrument as a nanometric machine tool motivates the search for an accurate model of the actuator for implementing feedback control. A simple nonlinear model describing longitudinal expansion of the piezoelectric tube actuator is presented in this paper. The model derivation is based on a non-formal analogy with nonlinear viscoelastic materials under uniaxial extension, for which the responses to a step input are similar to the piezoelectric tube. Suitability of the model structure for arbitrary inputs is tested by cross-verification between time and frequency domains. Two parameter estimation procedures are examined and the results of the experimental work for characterization, estimation and validation are presented.