Optimal Design of Novel Electromagnetic-Ring Active Balancing Actuator with Radial Excitation

Imbalance vibration is a typical failure mode of rotational machines and has significant negative effects on the effii-ciency,accuracy,and service life of equipment.To automatically reduce the imbalance vibration during the opera-tional process,different types of active balancing actuators have been designed and widely applied in actual produc-tion.However,the existing electromagnetic-ring active balancing actuator is designed based on an axial excitation structure which can cause structural instability and has low electromagnetic driving efficiency.In this paper,a novel radial excitation structure and the working principle of an electromagnetic-ring active balancing actuator with a combined driving strategy are presented in detail.Then,based on a finite element model,the performance param-eters of the actuator are analyzed,and reasonable design parameters are obtained.Self-locking torque measurements and comparative static and dynamic experiments are performed to validate the self-locking torque and driving effi-ciency of the actuator.The results indicate that this novel active balancing actuator has sufficient self-locking torque,achieves normal step rotation at 2000 r/min,and reduces the driving voltage by 12.5％.The proposed novel balancing actuator using radial excitation and a combination of permanent magnets and soft-iron blocks has improved electro-magnetic efficiency and a more stable and compact structure.     

Next generation actuators leading breakthroughs

Conventional actuators still play the most important roles in motion control of automated machines. However, for advanced machines and instruments with higher performance, the conventional motors seem to be difficult to satisfy the coming sophisticated demands. So, the development of innovative actuators is recognized as one of the most important subjects of the key technology for next generation. Present state of the technology related to innovative actuators is introduced with some examples developed in a national project for new actuators. Essentials to develop a new actuator and to put it to practical use are also commented.     

平面七杆机构混合驱动器运动链分析和综合

使用传统RTNA(realtimenon adjustable)马达和RTA(realtimeadjustable)马达混合驱动平面两自由度七杆机构 ,达到既可以提供输出的柔性 ,又可以降低费用的目的。先就平面两自由度七杆机构进行型综合 ,得到平面两自由度七杆机构的四种运动链 ;然后逐一分析每一种运动链 ,得出适合于混合驱动器的一种运动链。为平面两自由度七杆机构混合驱动器的分析和设计打下基础。     

Anti-windup embedded magnetic actuator applied for near-high-speed milling

A fuzzy anti-windup (AW) compensator is proposed and applied to the embedded cylindrical-array magnetic actuator (ECAMA) to ensure the superior performance of spindle position regulation for milling machines under actuator saturation. Since ECAMA is a type of active magnetic bearing (AMB), the supplied coil current and the induced magnetic force are both limited by the maximum current and power output of the AMB and the associated amplifier. Once the magnetic actuator is saturated, the required control input cannot be realized by ECAMA and may lead to drastic tremble of spindle position. In this work, an AW compensator, based on fuzzy logic algorithm, is therefore proposed to rectify the control input to ECAMA. By employing commercial software MATLAB/Simulink and signal processing interface, Module DS1104 by dSPACE, the efficacy of the fuzzy AW compensation is practically verified by intensive experiments.     

基于行波模型的结构响应控制研究

从理论和实验两方面研究了基于行波模型的结构梁响应控制方法。在梁及压电陶瓷作动器等处采用行波理论模型,导出了抑制柔性梁中行波传播的主动控制律及相应的控制补偿器。这是一个具有超越函数的补偿器．并在100～300Hz的中频段,根据近似拟合的补偿器进行了主动控制实验研究,实验结果达到了50％的良好的控制效果。     

一种主动阻尼式燃气作动器的设计及实验验证

为了减小导弹高超音速飞行时,其折叠式舵面在严酷的风载条件下展开到位时的冲击,设计了一种主动阻尼式内缩型燃气作动器,并研制了原理样机。在对作动器的结构、工作原理进行介绍的基础上,设计了其主要零部件并进行了有限元分析。确定了舵面风载荷模拟加载的方法并搭建了地面模拟加载实验系统。建立了作动器工作过程的数学模型和仿真模型,并利用MATLAB/Simulink进行了仿真分析,获得了作动器的主要技术参数,进行了地面模拟加载实验验证,结果表明:在顺风载荷条件下,作动器的活塞拉杆先加速运动,然后减速运动,最后以较小的速度运动到位,因此作动器具有良好的负载自适应能力。实验结果与仿真结果基本一致,可为后续工程应用提供参考。     

介电型电活性聚合物圆柱形驱动器的驱动效率

研究了介电型电活性聚合物(DEAP)驱动器的机电能量转换机理、能量损耗和驱动效率。建立了驱动器机电能量转换模型,并通过试验测算了驱动器等效电路的模型参数,分析了电极材料等因素对DEAP相对介电常数的影响。深入研究了驱动器漏电流损耗,试验验证了漏电流对驱动器性能的影响。最后,设计了驱动器驱动试验台,完成了不同行程的准静态驱动试验,数值计算了驱动器的驱动效率。结果表明:由于等效电路电容未参与能量转换,驱动器机电转换效率分别为17.6%和25.6%。低电压、小行程驱动时,试验误差与理论分析误差不超过15%;而高电压、大行程驱动时,DEAP膜的漏电流等非线性因素使其驱动效率变化明显。该结果可为DEAP圆柱形驱动器的优化设计及合理使用提供指导。     

太赫兹可调谐滤波器设计

为了实现太赫兹信号的可调谐滤波，设计了一种基于柔性材料的太赫兹可调谐滤波器。通过扭曲特氟龙（Teflon）波导形成环型谐振器，实现了160～200 GHz频段的带阻滤波功能。改变谐振腔长可实现自由频谱范围（FSR）和滤波频点的调谐，实验测试了自由频谱范围在1.9 GHz和2.8 GHz间切换以及相应的滤波特性。研究表明，谐振腔长一定时，改变弯曲半径可实现滤波阻带抑制度的调节，柔性材料太赫兹环型谐振器可用于可调谐滤波，且具有较高的自由度。     

电磁式作动器及其振动主动控制系统的研究

本文以旋转机械为研究对象，成功地研制了一种电磁式作动器及其振动主动控制系统，解决了信号检测，控制，放大以及数据通讯等一此关键性的难题，利用该系统，对转子的不平衡振动进行了主动控制实验，取得取较好的控制效果。     

介电型电活性聚合物圆柱驱动器特性

介电型电活性聚合物(Electroactive polymer, EAP)驱动器的动、静态特性是其合理使用及优化设计的重要依据。构建圆柱形驱动器几何模型描述其几何变形,结合EAP膜机电耦合方程推导驱动器轴向线性运动的动力学方程。驱动器的电压-位移数值计算结果显示内外层EAP膜柔性电极涂覆方式会影响驱动器位移。基于驱动器的电压位移关系,对其主要失效形式进行讨论。将基于neo-Hookean弹簧的1个时间常数黏弹性模型修正为具有2个时间常数的模型,并将2种模型运用于阶跃和周期电压激励下的驱动器动态响应研究。理论计算与试验结果的对比分析表明,2个时间常数的黏弹性模型对驱动器的动态位移描述更为准确。在周期激励电压下,提高频率会显著减小驱动器位移幅值,驱动器的“激励死区”会减小其振动中心偏移及振动幅度。     

MODAL TESTING AND FINITE ELEMENT MODELLING OF SUBSYSTEM IN HARD DISK DRIVE

Residual vibration is one of the primary mechanical problems that affect the dynamic characteristics of the head actuator assembly in hard disk drives, and the data access speed and positioning resolution. This paper presents the experimental modal testing and finite element modelling that are tailored to vibration testing in the head actuator assembly. The special excitation method has been applied for modal testing of the head actuator assembly, based on voice coil motor without altering the modal property of the structure in actual operating condition. The finite element models of the head actuator assembly have been developed, and various modes have been analysed. It is shown that the dynamic characteristics of the head actuator assembly are very complicated, in particular the vibration due to the lateral quasi-rigid body mode caused by the flexibility of the pivot, and mass and structure of the head actuator arm. It is thus essential to develop effective approaches to reduce the vibration of the lateral quasi-rigid mode and improve the dynamic characteristics of the head actuator assembly, so that high-performance HDD can be developed.     

Design of Components and Layout of Machines for Material Handling

Efficient material handling can reduce the amount of work in manufacturing operations. This paper discusses the design of components and the layout of machines from a material handling perspective. A way to reduce the material handling cost without compromising the component functionality is to choose satisfactory design options. The relationships between the design of the components and material handling are analysed to reduce the flow of material in a manufacturing system. In Model I, component routes are selected for a potential manufacturing system when only limited information regarding the layout of the machines is available. The selection of component routes is integrated with the determination of machine locations, the layout of single-row machines, and the layout of multi-row machines with equal areas, respectively, in Model II. Each problem is mathematically formulated and two algorithms are presented with illustrative examples.     

测量光路中调焦音圈电机特性的仿真分析

对测量光路中调焦音圈电机的特性进行了分析,通过对音圈电机特性的仿真,定性分析音圈电机设计参数对电机特性的影响情况。从建立音圈电机的数学模型出发,利用仿真软件Simulink实现音圈电机的建模、特性仿真。得到仿真结果后,通过适当调整电机的设计参数,分析电机特性的变化。仿真结果表明,音圈电机动子质量、磁钢磁密等参数的变化都对电机的响应时间、平稳性、稳态误差有较大的影响。在原设计的基础上,可适当地增加电机动子的质量以及磁钢磁密来减小响应时间和稳态误差。这些分析结果为音圈电机的加工、测量基础光路中调焦功能的实现奠定了基础。     

应用惯性冲击原理的非对称夹持式压电旋转驱动器的设计

针对目前压电驱动器主要使用非对称锯齿波电信号驱动压电晶体实现驱动的现状,采用对称电压信号驱动压电振子,设计了非对称夹持式压电旋转驱动器。用对称波电信号作用在压电双晶片振子上,产生正反两个方向大小不同的周期性惯性冲击力,驱动机构实现旋转位移。建立了压电旋转驱动器的动力学模型,分析了非对称夹持旋转驱动器实现大小不同惯性冲击力的原理以及压电旋转驱动器的运动过程。组成了压电旋转驱动器的测试系统,在不同电压幅值、频率的方波激励下,对压电旋转驱动器的平均步长进行了测试。结果表明:非对称夹持式压电旋转驱动器能实现较稳定的单向转动,最大行程为360°,最大承载能力超过300g,步长分辨率为5μrad,最大转动速度为4000μrad/s;驱动器样机在20V、2Hz的方波激励下,平均运动步长为12μrad,转动速度为24μrad/s。     

Design and analysis of a mini linear optical pickup actuator

This paper describes a mini linear optical pickup actuator. To reduce the size, inner yokes are designed to guide the mover and outer yokes of permanent magnets are removed. Magnetic circuit method is used to determine the thrust force. Virtual path method is proposed to analyze the open magnetic circuit analysis. The magnetic circuit of the proposed actuator can be a closed circuit due to the virtual path model of the outer magnetic flux. The validity of virtual path method is evaluated by comparing to the FEM analysis. Structural vibration is investigated using FEM and the design of the mover is modified to improve the vibration characteristic. Dynamic characteristic experiments shows that the performance of the proposed actuator is enough to be used as a coarse and fine seeking actuator simultaneously and the thrust force margin for loading a focusing actuator is guaranteed.     

High efficient driving circuit for traveling wave dielectrophoretic pump

The micro-fluidic systems based on the dielectrophoresis (DEP) phenomenon have become one of the hottest topics recently. By combining sensor and actuator into a system, a miniature traveling wave dielectrophoretic (TWDEP) pump can be widely used in biomedical applications. As often powered by lower voltage, the actuator of such a system must be minimized yet with adequate capability to drive the DEP pump to the required speed. The driving circuit for the actuator described in this study is designed and tested to attain the purpose of driving a TWDEP pump for whole blood samples. For improving the driving capability, four-phase AC fields were designed and the output levels were increased to double the supply voltage. Quantitative comparison between the driving circuit and function generator by velocity measurement was made. The driving circuit works properly for the steady state operation of the pump.     

DESIGN AND ANALYSIS OF NOVEL ACTIVE ACTUATOR TO CONTROL LOW FREQUENCY VIBRATIONS OF SHAFT SYSTEM

Aiming at providing with high-load capability in active vibration control of large-scale rotor system, a new type of active actuator to simultaneously reduce the dangers of low frequency flexural and torsional vibrations is designed. The actuator employs electro-hydraulic system and can provide a high and circumferential load. To initialize new research, the characteristics of various kinds of active actuators to control rotor shaft vibration are briefly introduced. The purpose of this paper is to introduce the preliminary results via presenting the structure, functions and operating principles, in particular, the working process of the electro-hydraulic system of the new actuator which includes a set of high speed electromagnetic valves and a series of sloping cone-shaped openings, and presenting the transmission relationships among the control parameters from control signals into the valves to active load onto shaft. The course of the work is dynamic, and a series of spatial forces and moments are put on the shaft to get an external resultant force to reduce excitations that induce vibration of shafts. By checking states of vibration, the actuator can control the impulse width and the interval of injection time for applying different control force to a vibration shaft in two circumference directions through the regulating action of a set of combination directional control valves. The results from simulating analysis and experiment show evidence of that this design can satisfy the case of active process of decreasing of flexural and torsional vibrations.     

气动执行机构封闭层与塞盘间阻力对动作效果的影响与研究

双作用气动执行机构因其出色的经济性和可靠性被广泛应用于工业领域,但也因为其控制精度较低而使用范围受限;研究主要利用流体力学和牛顿力学原理针对可调节气动执行机构控制精度低的缺点,使用Comsol软件对其气缸进行建模,在不考虑其他因素情况下利用施加封闭层与塞盘之间阻力的方法,对气动执行机构内塞盘动作效果影响进行模拟,研究其阻力大小的改变对于塞盘动作效果的影响,达到降低可调节气动执行机构控制误差的目的。     

Non-Contact Subsurface Defects Characterization by Microwave and Millimeter Wave Techniques

In this paper, a characterization technique for Non-Destructive Evaluation of dielectric materials by microwave and millimeter wave techniques is presented. The proposed method is based on the use of systems that allow the determination of the reflection coefficient S ₁₁ of the material under test and an artificial neural network (ANN) treatment. The systems that are considered in this study are on one hand a commercial vector network analyzer that operates in that frequency band [0.05–18 GHz] and on the other hand two systems, named S-Parameter Measurement Systems, that have been developed in our laboratory. The first one permits measurements between 1 and 4 GHz whereas the second operates at the frequency of 35 GHz. The investigation concerns dielectric materials that contain a defect of different nature. The defect width and burial depth vary from a few centimeters to a few microns so that a width ratio of more than one thousand is obtained between the biggest and the smallest defects considered. Characterization techniques and results are discussed through measurements and simulations, main benefits and drawbacks of each method are also analyzed in this paper.