压电柔性结构形状复合控制方法研究

以宏纤维复合材料(MFC)驱动柔性悬臂结构为研究对象,着重开展其动态形状控制理论研究。基于有限单元法、均匀化理论和载荷比拟方法,建立了压电驱动层合结构力 电耦合动力学方程,并结合模态降阶法得到其状态空间形式控制模型。同时,针对压电材料作动器迟滞蠕变非线性特征对控制精度影响严重的问题,开展了依据实验数据的迟滞蠕变建模及其前馈逆补偿控制方法的研究,并构建了面向压电驱动柔性结构动态形状控制的迟滞 蠕变前馈补偿与自抗扰反馈控制相结合的复合控制系统。结果表明,该复合控制法能够在保证系统稳定性的前提下有效提高系统动态形状控制精度。     

扫描探针显微镜中压电执行器回滞非线性软计算建模及其实时补偿

本文提出了自适应范围DNA(Adaptive Range DNA，简称ARDNA)软计算模型框架以及扫描探针显微镜(简称SPM)中压电执行器回滞非线性ARDNA建模及其补偿原理。基于基本回滞算子的线性叠加构建压电执行器回滞非线性模型结构，采用ARDNA软计算方法，同时优化模型结构(指简单回滞算子的个数及其阈值)和参数(指每个回滞算子的加权值)，建立最优的压电执行器回滞非线性模型。通过设计单位反馈控制器构建其逆模型，而压电执行器与其逆模型串联，由逆模型荻取参考位移所对应的理想激励电压，从而确保压电执行器输出跟踪参考位移，实现回滞非线性实时补偿。数字仿真结果表明了压电执行器回滞非线性建模及其补偿方法的有效性。本文的方法对形状记忆合金SMA(Shape Memory Alloy)、磁流变液体(Magnetorheological Fluids)等材料的回滞非线性建模和补偿也具有参考价值。     

电荷驱动在高速压电致动平台中的应用

一个高速压电驱动平台的性能经常被支撑结构的低谐振频率所限制。采用一种非对称致动器可消除传到基座上的惯性力,但传统的电压驱动方法会引起严重的率相关迟滞,惯性力补偿效果不佳。该文提出采用电荷驱动法来消除非对称致动器产生的惯性力。实验表明,在激励电压峰-峰值为20V时,采用电荷驱动法,在110Hz~10kHz内惯性力基本消除,补偿效果比电压驱动方法好。     

Design and control of a piezoelectric driven reticle assist device for prevention of reticle slip in lithography systems

This paper presents a device for managing the inertial loads on photoreticles of lithography scanners. At high scan accelerations, the reticle inertial load can approach the clamp force limit. As a result, nanometer-level presliding slip can occur. Reticle slip is one limitation on increasing the throughput of the lithography scanners. In this paper, we present a reticle assist device which can eliminate reticle slip by compensating better than 95% of the inertial loads when tested in a bench-top tester. The reticle assist device consists of a coarse approach mechanism, for accommodating reticle load/unload, and a piezoelectric stack for fine actuation. The device utilizes a sensorless control system design. The control system uses a self-sensing contact detection method, which is inspired by self-sensing scanning probe microscopy, to find the reticle edge. It also uses a charge amplifier with a novel hybrid hysteresis compensation technique to linearly control the piezoelectric actuator extension, without the need for closed-loop position control. When tested with a replicated force profile with 60 N peak force and 6400 N/s force rate, the assist device compensated better than 95% of the inertial load.     

Disturbance-Observer-Based Hysteresis Compensation for Piezoelectric Actuators

We present a novel hysteresis compensation method for piezoelectric actuators. We consider the hysteresis nonlinearity of the actuator as a disturbance over a linear system. A disturbance observer (DOB) is then utilized to estimate and compensate for the hysteresis nonlinearity. In contrast to the existing inverse-model-based approach, the DOB-based hysteresis compensation does not rely on any particular hysteresis model, and therefore provides a simple and effective compensation mechanism. We design and fabricate a lead magnesium niobate-lead titanate (PMN-PT) piezoelectric actuator for microscale tip-based power sintering process. Experimental validation of the proposed hysteresis compensation is performed on the PMN-PT cantilever piezoelectric actuator. The experimental results demonstrate the effectiveness and efficiency of the approach.      

宏微压电驱动器的电源设计与试验

针对超声电机与压电微驱动器对驱动电源的要求,设计出一种既能驱动超声电机又能驱动压电微驱动器的驱动电源,该驱动电源由可调变压器、半桥模块及以高性能数字信号处理(DSP)芯片TMS320F28335为核心的控制器组成。该电源驱动超声电机时,电源输出相位差、频率均较大范围连续可调的二相超声频率交流电;驱动压电驱动器时,电源输出较大范围连续可调的直流电。对行波型旋转超声电机及钹型压电驱动器的系列驱动试验表明该电源能同时满足超声电机和压电驱动器的驱动要求。     

基于GRU神经网络的晶圆测试工艺控制方法

压电驱动器位移输出的非线性特性,如迟滞的记忆特性及速率相关性,使压电驱动器的建模与控制较难。该文提出了一种基于门控循环单元(GRU)的新型位移输出控制方法。建立相应的位移输出实验平台来验证和分析压电驱动器的滞后现象。使用GRU模拟滞后的内存特性及采用两个全连接层来模拟速率依赖性。该模型是一个端到端系统,其中压电陶瓷和位移放大机构被视为一个整体。针对不同电压输入预测的输出位移量表明,该模型对速率相关的滞后具有很强的泛化能力。使用相同的循环神经网络结构构建逆模型,并进行实验测试。实验结果表明,所提出的位移输出控制法有效地削弱了压电驱动器的非线性特性,有利于将线性系统控制法与前馈补偿法相结合。     

高压共轨压电喷油器迟滞控制研究

通过Matlab/Simulink建立了压电堆执行器迟滞补偿模型,由压电堆执行器无外载静态试验获得了基于Maxwell粘-滑模型的迟滞特性模型参数,将模型用于高压共轨压电喷油器控制.实验结果表明,采用建立的迟滞补偿模型,通过开环前馈控制,有效抑制了压电堆执行器的迟滞影响,喷油率上升和下降速率减缓,有利于降低燃烧噪声和减小"水击现象"对喷油量波动的影响.     

压电陶瓷驱动器在机器人柔性臂应用中的研究

研究了片状压电陶瓷驱动器在柔性手臂中的应用,推导了基本压电陶瓷驱动器的柔性臂静力学方程,建立了描述驱动器迟滞特性的Ｐｒｅｉｓａｃｈ模型,提出了一种基于Ｐｒｅｉｓａｃｈ前钏环的ＰＩＤ掏方法对柔性夺动主动控制和轨迹控制俞中以有效地克服片状压电陶瓷驱动器的迟滞特性,消除柔性臂运动产生的振动,实现柔性臂的精度轨迹控制。     

四足压电驱动装置的电源设计与研究

压电驱动装置具有纳米级/微米级定位的特性,被广泛应用于精密控制运动平台中,故对压电驱动装置的速度和精度的要求越来越高。根据步进式压电马达驱动原理,结合四足压电驱动装置动力学模型,设计了一种用于新型叠堆结构的四足压电驱动装置的驱动电源。该电源是高电压为±250 V和高频率为1.5 kHz的线性电源,且采用硬件阻抗补偿和信号切换两种策略,进一步解决了容性负载对信号频宽影响的问题,使四足压电驱动装置高精度恒速输出。同时应用硬件在环仿真与测试的方法搭建了实验平台。实验结果表明,在精度为1 nm分辨率的激光干涉仪采集设备中,实现了点对点50.7 nm的四足压电驱动装置的运动测试。     

基于三角位移放大机构的压电制动器研究

提出了一种应用于压电制动器的微位移放大机构,该机构以叠层压电陶瓷为驱动元件,通过基于三角形放大原理的柔性铰链放大机构,放大叠层压电陶瓷的输出位移。分析了放大机构的运动及放大机理,建立了制动系统的力学模型,并利用ANSYS软件建立机构有限元模型进行仿真,在试制样机上对其输出特性进行了实验。实验测试结果表明,该机构对叠层压电陶瓷输出位移的放大倍数为3.2倍,与有限元仿真得到的放大倍数4倍相近,一阶固有频率为1 814Hz,最大输出力为44.1N(150V电压下),且该机构线性良好、分辨率高、迟滞效应较小。     

Parameter identification and hysteresis compensation of embedded piezoelectric stack actuators

A novel method for the identification of embedded piezoelectric stack actuator parameters in combination with a real-time capable hysteresis compensation measure is presented. The presented algorithms are based on the Maxwell resistive capacitor model and are particularly useful for the identification of piezoelectric actuators embedded in a high-precision micropositioning system where the disassembly of the complete system for separate actuator identification is not recommended or not possible. The parameter identification can be performed in a fully automated way and enables the adaptation of the compensation routine to the changed circumstances (temperature difference, wearing of actuators) as well. The hysteresis compensation method proposed here does not require significant CPU or memory resources. It can be implemented as an additional task on the already existing controller or a low-budget FPGA. As an example, the proposed method was validated experimentally by the parameter identification and hysteresis compensation of the piezoelectric actuators incorporated in a commercially available hybrid micropositioning system. The achieved experimental results are in very good agreement with the theoretical ones.     

压电执行器及其在液压阀中的应用

以压电执行器为核心的高速开关阀及伺服阀等压电式液压阀具有频响高,微动性能好,结构紧凑等优点,是新型阀控类型之一,受到国内外研究者的持续关注。首先,该文介绍了阀用压电执行器的分类和特点,根据工作原理分为直推式和步进式2类4种形式;其次,对先导型、直动型、喷嘴挡板型和开关型4种典型压电阀的研究进展进行了梳理,分析了各自的代表性结构、性能特点。结果表明,随着未来对液压阀精密化、智能化需求的提升,压电液压阀的应用前景更广。因此,除高性能介电材料开发外,如微位移放大、迟滞补偿控制等关键压电驱动与控制技术仍有待深入研究。     

压电叠堆执行器迟滞建模与前馈补偿研究

针对压电叠堆执行器输入电压与输出位移的动态迟滞特性,结合非对称静态Bouc-Wen迟滞模型,建立了压电叠堆执行器动态迟滞模型,并采用粒子群算法辨识出6个模型参数。为提高压电叠堆执行器动态位移输出精度,进一步推导出压电叠堆执行器迟滞逆模型,最终在此基础上对压电叠堆执行器进行前馈补偿研究。仿真与实验结果对比表明,在0~120V峰值电压与0~500Hz激励频率内,所建立的动态迟滞模型能够较好地描述与预测压电叠堆执行器的动态输出位移。前馈补偿实验研究结果表明,利用所建的迟滞逆模型补偿后,压电叠堆执行器的滞环减小,输出位移非线性度下降约3%。     

管道微机器人中压电执行器的研究

微执行器作为微机械系统的核心单元,一直是微机械发展关键。文章介绍了一种应用于管道微机器人的足式压电执行器。在交变电压作用下,该压电执行器将压电体的弯曲振动转化成其弹性足沿管壁的移动,从而实现执行器的运动。在分析其工作原理的基础上,研制了压电微执行器的驱动电源,并进行了简单的实验研究。研究表明该执行器具有结构简单,易于微型化,响应快,驱动方便等特点。     

一种高效压电旋转驱动器的设计和研究

为解决压电双晶片旋转驱动器能量利用效率低,转动力学性能差等问题,设计了一种高效压电旋转驱动器。驱动器以压电双晶片组为原动件,通过双离合器机构耦合,将双晶片组正、反两个方向产生的扭转运动全部转化为连续旋转输出,提高了能量利用效率。通过双晶片组对称结构的设计和安装,改善了驱动器力学性能和刚度。通过有限元仿真分析和实际测试,驱动器转速与驱动信号的频率电压基本成线性关系,驱动器承载能力明显提升。驱动器结构紧凑,体积小,普通正弦信号即可驱动,不需要特殊驱动信号或专门时序控制电路,运行稳定可靠,控制简单高效,适用于微驱动领域。     

An I-shape linear piezoelectric actuator using resonant type longitudinal vibration transducers

Resonant type longitudinal vibration transducers are used in this work to construct a linear piezoelectric actuator with four driving feet. Totally three longitudinal transducers are integrated in I-shape to form the proposed actuator, which contains one vertical transducer and two horizontal transducers. These three transducers vibrate under longitudinal modes with certain temporal sequence, whose vibrations are superimposed in the actuator to generate elliptical motions on the four driving feet. The three transducers are tuned to be suitable dimensions, under which they have very close 1st longitudinal resonance frequencies; the working frequency of the piezoelectric actuator is designed to be about 31.3 kHz. The vibration coupling problem between the longitudinal transducers are studied by calculating the motion trajectories of the four feet. It is found that the temporal shift of the longitudinal vibrations can be used to tune the movement trajectories; the four feet can get nearly the same vertical displacements under a phase shift of 105°. At last, the vibration characteristics and mechanical output performances of a prototype are measured. The working frequency of the prototype, the maximum speed, and the maximum thrust force are measured to be 33.15 kHz, 1563 mm/s, and 158.2 N, respectively.     

Self-Powered Piezoelectric Actuation Systems Based on Triboelectric Nanogenerator

Sustainable power supply via triboelectric nanogenerator (TENG) is attractive for self-powered actuation systems in the era of the Internet of Things (IoTs). Herein, a low-power actuation scheme enabled by the multilayered TENG for piezoelectric actuators, including the stack, unimorph, and micro-fiber composite (MFC) actuator, is reported. The working principles of TENG-powered piezoelectric actuators and their displacement characteristics in direct current (DC) and alternating current (AC) modes are theoretically investigated. Compared with conventional high-voltage power sources, the multilayered TENG delivers a maximum power of only 10.17 mW, providing a low-power alternative for piezoelectric actuator with self-powered capability and operational safety. Meanwhile, the hysteresis of the stack actuator that is critical in precise positioning control is reduced by 58.1%. A precise positioning system is demonstrated by utilizing the TENG-powered stack actuator as an object stage for microscope focusing applications. The feasibility of vibration control with a 76.7% reduction in vibration amplitude is also verified via two TENG-powered MFC actuators. A rectifying control circuit comprising the rectifier and gas discharging tube is established to implement AC–DC conversion and discharging control, achieving a larger displacement of the unimorph actuator. The TENG-powered piezoelectric micropump demonstrates its potential application in liquid transport through straightforward operation.     

压电执行器非线性控制方法研究进展

压电执行器在微驱动和微定位领域应用广泛,但压电执行器在输入电压和输出位移间存在着迟滞非线性。非线性的存在使压电执行器定位精度降低,动态响应速度变慢,是其工程上进一步应用的主要障碍。减小和消除迟滞非线性成为实现高精度控制的关键。总结了近年来国内外在减小和消除压电执行器迟滞非线性方面上的研究工作,并指出当今研究的热点及未来研究的方向。     

压电双晶片阵列式直线驱动器的设计与研究

基于压电双晶片提出一种新型准静态直线压电驱动器,可通过阵列的方式获得所需机械输出力,结构简单,性能稳定,可控性强。利用有限元软件对驱动器结构进行设计与分析,并加工制造了该驱动器的物理样机。最后通过实验发现,当驱动频率为500~2 100Hz时,驱动器可直接输出直线运动。当驱动频率为1 100Hz,驱动电压峰-峰值为200V,预紧力为1.5N时,该驱动器最大输出速度可达95mm/s,最大输出力为0.7N。