超磁致伸缩材料传感/执行器的原理与应用

超磁致伸缩材料作为一种新型功能材料,具有大磁致伸缩系数、高能量密度、低磁场驱动、高磁机转换效率以及快速响应等优点,在精密驱动技术中得到应用。利用磁致伸缩正效应可以开发微位移执行器、力驱动器和振动器等;利用磁致伸缩逆效应可以开发力、力矩和位移传感器以及能量转换器;利用磁致伸缩正逆耦合效应可以开发集驱动、力测量、输出力感知和输出力可控等功能于一体的器件,应用于精密驱动领域。在分析了磁致伸缩正效应、逆效应以及正逆耦合效应机理的基础上,阐述了超磁致伸缩传感器、执行器以及传感执行一体化器件的开发原理及其应用现状。     

超磁致伸缩激振器的性能指标与测试技术研究

以工程应用为导向,该文阐述了超磁致伸缩激振器的性能指标和测试技术,有效利用超磁致伸缩材料的倍频效应,可以降低驱动磁场频率在200 Hz以下,同时简化驱动线圈结构。静态力常数是综合反映超磁致伸缩激振器静态性能的重要指标,阶跃响应和幅频特性是反映超磁致伸缩激振器动态性能的主要指标,在满足最大激振力要求的前提下,激振器的设计应以提高动态性能为出发点。试验表明,输出位移和激振力符合设计要求,可做为制定技术标准的参考依据,系统模型和测试技术具有工程应用价值。     

基于逆磁致伸缩效应的超磁致伸缩磁力控制器件建模

超磁致伸缩器件的输入应力与输出磁通密度存在着滞回非线性.基于Jiles-Atherton模型、磁机械效应方法定律和磁路定律,建立一个超磁致伸缩磁力控制器件的滞回模型.试验结果表明,该模型能较好地描述在变化应力和恒定偏置磁场作用下,超磁致伸缩器件输入应力与输出磁通密度及磁力的滞回关系,并可以预测偏置磁场对器件输出性能的影响,从而对器件的设计与分析具有重要指导意义.     

基于磁致伸缩逆效应的超磁致伸缩力传感器

磁致伸缩逆效应是稀土超磁致伸缩材料的一个重要应用特性,应用磁致伸缩逆效应可以制作超磁致伸缩力传感器。但由于缺乏相应的设计理论分析,从而制约了其发展。在分析了磁致伸缩逆效应的基础上,给出了超磁致伸缩力传感器的设计原理,设计了超磁致伸缩力传感器的结构,并采用数值计算方法对其磁场进行了计算。计算结果与实验结果的比较表明:二者符合较好,设计的超磁致伸缩力传感器方案是可行的,对其今后进行深入应用研究和优化设计具有重要意义。     

超磁致伸缩致动器结构分析及输出力特性研究

在超磁致伸缩致动器(GMA)工作原理的基础上,完成了具有分段式偏置磁场和油冷散热系统的GMA机械结构设计;建立了GMA的3D模型,利用有限元分析软件对其磁场和温度场进行了仿真研究,结果表明分段式偏置磁场有较好的偏置效果,油冷散热方式冷却效果明显;搭建了GMA输出力特性测试平台,分别对直流激励下GMA的静态输出力特性和低频交流激励下动态输出力特性进行了研究;实验表明GMA的输出力与激励电流正相关,在直流激励下,输出力具有磁滞非线性,且受温度影响较大,受外部约束力影响较小;在交流激励下,输出力能很好地跟踪交流信号频率,未出现倍频效应,说明分段式偏置效果较好,GMA具有较高的精度和动态响应速度。     

超磁致伸缩微位移驱动器设计

针对超磁致伸缩材料,设计一种超磁致伸缩微位移驱动器并实现对其控制。在分析超磁致伸缩材料工作特性和超磁致伸缩驱动器工作原理的基础上,确定超磁致伸缩驱动器的结构参数,并应用有限元软件对超磁致伸缩驱动器的机械结构进行电磁场分析,比较无偏置磁场和含偏置磁场下超磁致伸缩材料所处位置的平均磁场强度,验证驱动器机械结构的合理性。同时设计压控电流源,利用基于数字信号处理器的控制器中数模转换电路控制压控电流源,使激励线圈配合偏置线圈产生所需磁场。实验表明,在给定预紧力和偏置磁场条件下,超磁致伸缩材料在2A激励电流下可输出行程为27.1μm,位移精度0.1μm,磁滞回线的平均厚度为3.29μm,验证了超磁致伸缩驱动器结构设计的合理性。     

偏置优化对Terfenol-D致动器性能的影响

从分析Terfenol-D材料的磁致伸缩机理出发,引申出预应力和偏置磁场是影响超磁致伸缩致动器性能的重要因素.零偏置磁场驱动下不同预应力对致动器位移输出影响的实验和零预应力下两种偏置磁场对致动器输出性能的比较实验,验证了合理选择预应力和偏置磁场可有效地改善致动器性能的论点.预应力和磁偏置的实验矩阵确定了不同预应力对应的优化偏置磁场,实际设计中需根据致动器要求确定优化的偏置条件.     

超磁致伸缩电-机转换器的驱动磁路设计

在介绍了超磁致伸缩电-机转换器(Giant Magnetostrictive Actuator,简称GMA)的基本结构和工作原理的基础上,分析了磁场特性对转换器性能的影响.利用相关电磁学和磁路设计的基本理论,采用双线圈式驱动形式,对转换器的磁路进行设计和分析,给出了驱动线圈和偏置线圈结构参数的计算方法.为优化超磁致伸缩电-机转换器的磁路结构提供了理论依据.     

稀土超磁致伸缩应力测试仪的设计及实验研究

基于超磁致伸缩材料自身在不同偏置磁场下应力和应变之间的复杂非线性关系.以单片机89C52为核心设计了稀土超磁致伸缩应力测试仪.该测试仪的硬件由静态电阻应变仪和89C52控制电路2部分组成,软件部分主要完成应力和应变之间复杂关系的拟合计算.进行了一定偏置磁场下超磁致伸缩器件的应力和应变的测试,测试结果表明:该应力测试仪工作稳定,应力测量结果可靠.目前该应力测试仪已经在杭州715研究所投入使用.     

超磁致伸缩材料力传感执行器关键技术研究

正超磁致伸缩材料以其大磁致伸缩系数、高机电耦合系数、快速响应能力、易于驱动等特点而备受关注。该材料具有强磁致伸缩正效应和磁致伸缩逆效应,在工作过程中表现出双向能量转换特性。利用磁致伸缩正效应可制作驱动装置,利用磁致伸缩逆效应可制作传感器。当超磁致伸缩材料工作在机械约束条件下,磁致伸缩正效应和逆效应会发生耦合。如果研究磁致伸缩正逆效应耦合特性,可利用正逆耦合效应开发兼具执行和传感功能的磁致伸缩器件。开发单体微位移驱动设备使之兼具执行和传感等多种用途,是微位移驱动领域理论研究与工程应用的趋势所在;并且,在精密、超精密加工领域,例如精密机械抛光加工中的压力控制,需要一种具有恒定输出力或输出力可控的驱动机构。因此,利用超磁致伸缩材料的磁致伸缩正逆     

磁致伸缩式扭转超声波位移传感器的研究与设计

介绍磁致伸缩式扭转超声波位移传感器的工作原理及设计机制。该传感器利用磁致伸缩的Wiedeman效应发射扭转波，利用磁致伸缩逆效应接收回波信号，根据发射脉冲与回波信号的时间差计算活动磁铁的位置，由于磁致伸缩材料和扭转波传播的特性，以及测量电路对于精确测时功能的实现，使和该传感器同时具有精度高，成本低，寿命长和安装简便，适用范围宽等优点。     

超磁致伸缩驱动器建模及其迟滞补偿

本文提出了用超磁致伸缩材料与压曲放大机构相结合构成微位移驱动器的方法,建立了超磁致伸缩执行器的控制系统传递函数模型。文中对所建立的系统进行了相频和幅频特性的理论分析和实验,合理地解释了此系统的迟滞曲线随输入信号频率变化的原因。为了进行迟滞非线性补偿,提出了相位补偿与迟滞逆模型相结合来补偿迟滞特性的控制方法。实验结果证明了系统理论模型的准确性和补偿控制方法的有效性。     

A giant magnetostrictive actuator based on use of permanent magnet

The giant magnetostrictive actuator has some unique performances, such as precision position resolution, several kilonewtons of force output, fast frequency response, etc., so it is suitable for the field of ultraprecision measurement and ultraprecision machining. Due to the effect of temperature, the displacement of traditional giant magnetostrictive actuator based on the use of electromagnetism transforming must present nonlinearity. For avoiding this problem, a kind of giant magnetostrictive actuator based on the use of permanent magnet is present in this paper. The driving magnetic field generated by permanent magnetic field can avoid skin effect and eddy current caused by electromagnetism transforming mode for giant magnetostrictive actuator and the performances of actuator are better than that based on electromagnetism transforming. The structure and principle about this driving mode are described in this paper and the value and uniformity of magnetic field affected by some key parameters are mainly discussed in this paper. At last, through several experiments of displacement and creep, it is verified that the driving mode of actuator based on use of permanent magnet is advanced.     

A novel magnetostrictive static force sensor based on the giant magnetostrictive material

In order to realize static force measuring and improve the sensitivity of magnetostrictive force sensor, a novel magnetostrictive static force sensor with giant magnetostrictive material rod is presented. A Hall sensor integrated in the sensor is used to measure magnetic flux density variation under force. A special structure surrounding Hall sensor is proposed to improve the sensitivity. The design method of the giant magnetostrictive force sensor is expounded firstly. The magnetic characteristics are analyzed by FEM. A model is developed based on the coupled linear magnetomechanical constitutive equations and the experimental result shows that the model is good at reflecting the force. The optimal bias magnetic field and sensitivity are studied through experiments. The sensor sensitivity is 6.14 times higher than that of the sensor which dose not have a stainless steel ring. The paper lays a foundation for the development of magnetostrictive force sensor with giant magnetostrictive material.     

超磁致伸缩力传感器及其实验研究

超磁致伸缩材料具有相对磁导率高、磁机转换率高等优良特性,对于传感器装置是一种很好的材料.文中基于维拉里效应原理完成了超磁致伸缩力传感器的设计,并利用有限元分析方法验证了所设计传感器磁场分布的合理性.提出了基于电感测童力传感器输出特性的方法,并进行了实验,确定了该传感器的灵敏度最高状态的最佳偏置磁场强度;并测量了0～10(3)作用力下传感器的输出特性,实验结果表明该传感器输出特性良好,可用于高精度要求的场合.     

Magnetostrictive and Kinematic Model Considering the Dynamic Hysteresis and Energy Loss for GMA

Due to the influence of magnetic hysteresis and energy loss inherent in giant magnetostrictive materials (GMM), output displacement accuracy of giant magnetostrictive actuator (GMA) can not meet the precision and ultra precision machining. Using a GMM rod as the core driving element, a GMA which may be used in the field of precision and ultra precision drive engineering is designed through modular design method. Based on the Armstrong theory and elastic Gibbs free energy theory, a nonlinear magnetostriction model which considers magnetic hysteresis and energy loss characteristics is established. Moreover, the mechanical system differential equation model for GMA is established by utilizing D’Alembert’s principle. Experimental results show that the model can preferably predict magnetization property, magnetic potential orientation, energy loss for GMM. It is also able to describe magnetostrictive elongation and output displacement of GMA. Research results will provide a theoretical basis for solving the dynamic magnetic hysteresis, energy loss and working precision for GMA fundamentally.     

偏置磁场对磁致伸缩液位传感器检测电压的影响

为了提高磁致伸缩液位传感器的检测精度,研究了磁致伸缩液位传感器中产生偏置磁场的浮子磁铁的放置方式及其对检测电压的影响。利用ANSYS软件对浮子磁铁不同放置方式下形成的偏置磁场进行了有限元分析,分析显示:采用3块磁铁互成120°N极N极S极(NNS)放置或者采用圆环磁铁作为偏置磁场时检测效果比较理想。实验研究了磁致伸缩液位传感器的偏置磁场对检测电压的影响,并在浮子磁铁不同放置方式下进行多次实验。结果表明:偏置磁铁为3块磁铁互成120°NNS放置时或者为圆环磁铁时,检测电压的幅值达到50mV,比其它放置方式提高了近30mV。研究表明:磁致伸缩液位传感器应选择3块磁铁NNS放置或者选择圆环磁铁作为偏置磁场。     

Signal separation technology for diphase opposition giant magnetostrictive self-sensing actuator

The structure and principle of a new type of a diphase opposition giant magnetostrictive self-sensing actuator is introduced. A bridge analysis model based on variable inductance is established. Dynamic balance separation technology for the giant magnetostrictive self-sensing actuator comes true by the least means square (LMS) self-adapting algorithm. The scheme design of one important part of the circuit with the real-time separation circuit of the dynamic balance signal based on a digital signal processor is obtained. The part of the signal separated circuit is designed, which includes logarithmic-antilog practical multiplication circuit, amplifying circuit, filter circuits, and amplifier circuit. Based on the embedded system simulation software—PROTUES, the simulation effect of the circuit that separates the sensing signal from the mixed signals is obvious, which indicates that the circuit can rapidly and stably work. Moreover, the structure is simple, reliable, and meets the practical requirement.     

Signal separation technology for diphase opposition giant magnetostrictive self-sensing actuator

The structure and principle of a new type of a diphase opposition giant magnetostrictive self-sensing actuator is introduced. A bridge analysis model based on variable inductance is established. Dynamic balance separation technology for the giant magnetostrictive self-sensing actuator comes true by the least means square (LMS) self-adapting algorithm. The scheme design of one important part of the circuit with the real-time separation circuit of the dynamic balance signal based on a digital signal processor is obtained. The part of the signal separated circuit is designed, which includes logarithmicantilog practical multiplication circuit, amplifying circuit, filter circuits, and amplifier circuit. Based on the embedded system simulation software—PROTUES, the simulation effect of the circuit that separates the sensing signal from the mixed signals is obvious, which indicates that the circuit can rapidly and stably work. Moreover, the structure is simple, reliable, and meets the practical requirement.     

磁致伸缩压力传感器设计及其输出特性

研究了铁镓合金(Galfenol)的磁致伸缩特性,提出一种基于Galfenol的新型磁致伸缩压力传感器,以实现机器人的触觉力精确感知。该传感器利用磁致伸缩逆效应将压力转换为电压信号,从而完成对压力的精确测量。设计、制作了磁致伸缩压力传感器,采用双永磁体回形磁路优化了压力传感器的磁场。对传感器进行了理论分析与实验研究,讨论了偏置条件、外压力等因素对输出电压峰值的影响。实验结果表明,在偏置磁场为4.8kA/m、施加的压力为2.5Hz、6N时,传感器的输出电压峰值达16mV,且输出电压峰值与压力呈较好的线性关系。研制的传感器具有结构简单、线性度好、反应速度快等特点,可以满足机器人触觉感知的需求,也可应用于其他领域的压力测量。