应用于干涉显微镜的直线压电作动器

提出了应用于干涉显微镜焦距调节的直线压电叠堆作动器和微动台.介绍了基于三角位移放大原理的压电作动器结构设计,利用ANSYS的APDL语言实现了对作动器钢架结构的建模,并采用Optimus中自带的差分进化算法(DE)对其结构尺寸进行了优化.制作了实验样机,激光干涉实验表明:当驱动电压信号幅值为40～100 V时,作动器位移放大倍数可以达到7.最后,将设计的直线作动器作为驱动核心安装在自行设计的微动台上,然后将组成的系统用于光学干涉显微镜.实验显示,整个系统在电压为24～40 V,阶梯增量电压为0.8V时,步进分辨率可达23 nm,满足干涉显微镜细分干涉条纹所需要的直线位移分辨率的要求.     

电液伺服装置的嵌入式数字控制器研究

在电液伺服装置中采用嵌入式数字控制器,使其具有面向用户的柔性设置和智能控制等功能,实现了液压伺服装置的数字化.     

PZT actuator applied to a femto-liter droplet ejector

Since the rapid advancement of the ink-jet printing technology, microdroplet ejectors have been developed into one of the essential fluid handling devices for delivering miniature liquid droplets in accurate dosage control. The applications of micro-droplet ejectors are increasingly prevalent in various emerging areas, for instance organic/polymer lighting emitting displays, liquid crystal display, optical communication, biochemical sample transport and screening and integrated circuit cooling devices. Among different inkjet printing technologies, piezoelectric driven droplet ejectors have shown their potential in dispensing diverse liquids. In this article, a novel femto-liter droplet ejector is proposed using a shear-type PZT actuator. To assure the workability of the ejector, the characteristics of the actuator were well investigated. Before integrating into the vibration plate of the ejector, the response of the rectangular plate-shaped actuator was evaluated by suspending the actuator on a fixture with both ends fixed. With a pre-specified driven waveform, the actuator vibrates to achieve satisfactory responses of displacement and velocity. Subsequently, the actuator was attached to the vibration plate as an actuating module for the ejector. The vibration plate has the design feature of a pillar on a diaphragm. The actuator pushed the pillar and thus deflected the diaphragm. The dimensions of the actuating module have been optimized by numerical simulations. The properties of diaphragm deformation and actuator transient response of the actuating module were simulated and measured for comparison purpose as well.     

Electromagnetic actuator for determining frequency response functions of dynamic modal testing on milling tool

Machine tools are the main driving forces of industrialization of a country. However, poor machinability because of chatter vibration results in poor surface quality, excessive noise, and reduced material removal rate. Modal testing is a useful method to investigate dynamic properties of a cutting tool system and improve material removal rate. However, at present, modal testing using impact hammer is limited by certain problems. This paper developed a non-contacting electromagnetic actuator (EMA) to determine frequency response functions (FRFs) under amplitude and speed dependencies of cutting milling tools. The geometry was designed using magnetic circuit analysis and generalized machined theory before finite element analysis was conducted using magnetostatic-ansys software. Next, EMA was used as a contacting and non-contacting exciter of a conventional milling machine to determine the FRFs and dynamic properties of milling tool with amplitude and speed dependencies including comparison with static FRFs. Subsequently, dynamic properties and FRFs are used to establish stability lobe diagram. Stability lobe diagram also shows an improvement of up to 5% of depth of cut at lower spindle speed. In conclusion, by generating force that applies to static and dynamic modal testing, an EMA can determine dynamic properties and stability lobe diagram for increasing material removal rate and production rate.     

植入光纤光栅的软体驱动器形状传感研究

软体机器人由于具有柔顺性和适应性等特点,在外科手术和狭窄空间等方面具有无可比拟的优势,为了实现微创手术等狭小空间中软体驱动器的姿态传感监测,提出基于植入式光纤光栅的柔性传感方法,首先将光纤布拉格光栅（FBG）植入在软体驱动器中;然后在软体驱动器的不同弯曲状态下,通过实验测试分析FBG点的光谱、波长漂移量和曲率等信息,利用3次样条插值等算法实现软体驱动器的三维形状拟合重构。实验结果表明,驱动器实际弯曲角度和重构算法之间的误差不足45%,传感器重复性的偏差指数不足7%。所提出的基于植入式光纤光栅的柔性传感方法可以实现软体机器人的姿态传感监测,在医疗外科手术领域具有广阔的应用前景。     

Cutting dynamics and process-structure interactions applied to milling

Cutting dynamics should not be restricted only to self-excited chatter vibrations. Transient disturbances are superimposed on stable working conditions and these dynamic components provide useful information on the real behaviour of the whole machining process. Cutting dynamics therefore include the analysis of such signals in the entire frequency range. An introduction to the basic dynamics of milling processes is presented.Milling is a cutting operation during which the periodic sequence of cutting edges generates periodic time signals with discrete force and vibration spectra. A single cutting pulse from the series of successive cuts leads to an aperiodic time function and thus to a continuous spectrum. Since the dynamic behaviour is known at all frequencies a study of the influence of various cutting conditions and the interactions between the cutting process and the machine tool structure is possible. The discrete spectrum of a real cut involving many teeth can be deduced from the corresponding single cutting pulse.A simple cutting force model was assumed in the theoretical analysis in order to give an initial rough idea of the fundamental properties of the milling pulses (frequency content of the spectra, spatial excitation locus and excitation ratio) as a function of the most important parameters (total cutting angle, up and down milling, symmetrical and asymmetrical cut and number of teeth). The computed results were compared with experimentally obtained data.     

不对称结构双稳态永磁驱动器研究

提出了一种不对称结构双稳态永磁驱动器方案,通过改变工作气隙区域内磁路结构,使真空断路器动作时增加了有效驱动行程,实现了快速运行,减少了分闸冲击,延长了真空管的机械寿命。通过磁路分析和有限元分析计算了不对称结构双稳态永磁驱动器的静态力／位移特性。仿真结果表明,本研究设计的双稳态永磁操动机构符合要求。     

Regulation of spindle position by magnetic actuator array

A novel embedded cylindrical-array magnetic actuator (ECAMA) is proposed and verified by experiments to provide sufficient magnetic force for spindle deviation regulation of high-speed milling process. Four I-shape silicon steel columns enclosing the spindle constitute the backbone of the ECAMA. The shape of modified concave-type yokes is designed to reduce the average air gap between magnetic poles and the spindle. In contrast to the conventional AMB (active magnetic bearing) design for which coils are usually wound on the yokes, the copper wire is wound on the I-shape silicon steel columns. As a result, the overall wound coil turns can be much increased. In other words, stronger magnetic force can be induced by ECAMA. On the other hand, to reduce the cost of ECAMA, two pairs of self-sensing modules are employed to replace the gap sensors for measurement of spindle position deviation. In order to verify the efficacy of the proposed ECAMA and the self-sensing module, high-speed milling tests are undertaken. By inspection on the precision and quality of the finish surface of workpiece, the superiority of ECAMA and the self-sensing module are assured.     

叠堆式超磁致伸缩致动器磁场分布建模及分析

为提高超磁致伸缩致动器(GMA)偏置磁场的均匀度,设计了叠堆式超磁致伸缩致动器(SGMA),建立了SGMA的磁场分布模型,并对模型进行分析研究。首先,通过分析传统GMA偏磁施加方式的特点和不足,采用永磁体和GMM棒交替排布的结构形式,设计了SGMA;然后,将磁路模型和毕奥-萨伐尔定律相结合,建立了能够准确描述SGMA磁场特点的磁场分布模型;接着,利用所建立磁场分布模型分析了不同参数对SGMA磁场分布特征的影响,提出了SGMA结构设计方法;最后,通过实验完成了模型验证。结果表明:采用本文建立的模型描述SGMA磁场分布时,最大相对误差低于4%;在预测SGMA的输出位移时,最大相对误差低于5%。该模型有助于准确刻画SGMA的工作状态,提高SGMA的系统精度,并为SGMA结构设计提供参考依据。     

超磁致伸缩驱动器驱动磁场仿真分析

为了充分发挥超磁致伸缩驱动器的特性,提高超磁致伸缩驱动器驱动磁场的性能,通过采用电流励磁法,建立基于磁感应强度为控制变量的单层空心线圈、多层空心线圈和带超磁致伸缩棒的多层线圈的轴线磁感应强度数学模型,分析超磁致伸缩棒、线圈长度和线圈半径对驱动磁场的均匀性和驱动磁场大小的影响.仿真结果表明,减小超磁致伸缩棒与驱动线圈之间的气隙,能提高驱动磁场的线性度;在满足设计要求的范围内,增加线圈长度,减小线圈半径,能够提高驱动磁场均匀性;仿真结果对超磁致伸缩驱动器驱动磁场的设计提供了一定的理论依据.     

电液驱动球阀的设计

阐述了PN6 4MPaDN5 0mm电液驱动球阀的工作原理、性能、用途和设计计算。     

Design and control of a new linear magnetic actuator for squeeze film damper

A new model of a linear magnetic actuator (LMA) that can be applied to the controllable squeeze film damper (CSFD) was proposed, designed, and fabricated. To validate the operation of the proposed actuator, a mathematical model of the proposed LMA was derived through experiments. From the experimental results it was verified that the electromagnetic force depends upon the position of the mover (the outer damper ring of the CSFD) and the applied current. Also, the electromagnetic force varies symmetrically with the position of the mover within the working region. A self-tuning fuzzy PID controller was applied to control the position of the novel LMA. Further, the proposed LMA was assembled in the squeeze film damper (SFD), where the clearance can be controlled by LMA. To investigate the damping effect of the damper under various clearances by controlling the LMA, experiments on the rotor test-rig were conducted. From the experimental results, the proposed device, which is composed of SFD and LMA, was verified to be very effective for attenuation of the vibration of the rotor system. This paper was recommended for publication in revised form by Associate Editor Dong Hwan Kim Kyoung Kwan Ahn received the B.S. degree in the department of Mechanical Engineering from Seoul National University in 1990, the M. Sc. degree in Mechanical Engineering from Korea Advanced Institute of Science and Technology (KAIST) in 1992 and the Ph.D. degree with the title “A study on the automation of out-door tasks using 2 link electro-hydraulic manipulator” from Tokyo Institute of Technology in 1999. He is currently a Professor in the School of Mechanical and Automotive Engineering, University of Ulsan, Ulsan, Korea. His research interests are design and control of smart actuator using smart material, fluid power control and active damping control. He is a Member of IEEE, ASME, SICE, RSJ, JSME, KSME, KSPE, KSAE, KFPS, and JFPS. Truong Quoc Thanh received the B.S degree in the department of Mechanical Engineering from Hochiminh City University of Technology in 1998, and the M.Sc. degree with title “Dynamic stiffness method in calculation vibration of structure” from the master program of mechanics under Inter-University Cooperation Program between Liege University (Belgium) and HCMUT (Vietnam) in 2000. From 2000 to 2004, he worked as a lecturer in the mechanical department of Hochiminh City University of Technology. His teaching subjects are relevant in Advanced Manufacturing Methods, Measuring Technique and Manufacturing Technique. He is currently a Ph.D. candidate at the University of Ulsan. His research interests focus on designing and manufacturing of new actuators, vibration control theory and application theories.     

一种新的刀补算法在铣削加工仿真的应用

本文在分析传统刀具补偿算法不足的基础上,提出了一种新的刀具补偿算法,简单易懂,并给出了详细的流程图,特别适合于编制刀具补偿程序。该算法不仅避开了复杂的Voronoi图理论和转接矢量运算,而且更易于在计算机上实现该算法。在基于RTLinux开放式数控系统中,该算法用于铣削加工仿真,速度较快,运行性能良好。     

Sensors and actuator fault tolerant control applied in a double pipe heat exchanger

In this work, we present the design of a Fault-Tolerant Control (FTC) system, applied in the outlet temperature sensors and in the control valve (actuator) of a concentric double pipe counter-current flow heat exchanger. The FTC consists in a sensors Fault Detection and Isolation (FDI) system and an actuator FDI system. The sensors FDI system is based on analytical redundancy, in such a way that a bank of modified Kalman filters is developed in order to estimate the two outlet temperatures of the heat exchanger. To develop the modified Kalman filters a multi-linear models approach is used. So that, if a sensor fault is detected by the FDI system the measured temperature signal is replaced by the temperature estimation provided by the modified Kalman filter. Moreover, to detect an actuator fault a comparison between the control valve behaviors (the control valve voltage is used to estimate the water flow rate) and a predefined flow rate for each linear model is carried out. In order to keep the continuous operation of the heat exchanger even in fault presence a model-following control law is introduced, such that, when an actuator fault occurs, the FDI system detect the fault and immediately the model-following control makes the fault accommodation in order to compensate the actuator fault. The proposed scheme is presented with experimental data on-line. The successful tests are presented and discussed.     

柔性多体系统动力学理论应用于轧制工业的综述

结合轧制工业的发展现状及柔性多体系统动力学的理论成果,从轧机设备的设计、改造、过程控制、系统特性、接触-碰撞问题的建模、轧制过程中多领域集成化、多体动力学软件的发展等几个方面阐述了将柔性多体系统动力学理论应用于轧制工业的可行性和必要性.     

基于FPGA的磁悬浮微驱动器控制系统研究

针对磁悬浮微驱动器的实时精确控制问题,对新型绕组式磁悬浮微驱动器的结构与工作原理进行了研究,对磁悬浮微驱动器中的磁场分布进行了理论分析,提出了一种基于FPGA的磁悬浮微驱动器悬浮系统的运动模型以及PID控制系统,并通过Matlab仿真实验验证了该数学模型。完成了系统的硬件控制电路及相应的软件设计,搭建了基于FPGA的磁悬浮微驱动器悬浮控制实验系统。该系统可利用位置环对磁悬浮微驱动器进行PID控制,并在上位机Delphi界面中显示悬浮状态,通过对所设计的PID控制器的控制精度、大范围精确控制性能、动态性能和跟踪性能进行了实验验证。实验结果表明,该系统响应速度快、可靠性高,可实现2 mm范围的精度为1μm的控制。     

基于ARM9的嵌入式数控铣床控制系统的设计

传统数控系统硬件大多基于通用计算机或工业控制计算机之上,软件基于Windows平台。软硬件成本高、功耗大、资源浪费。文章给出了一种基于Linux操作系统,以ARM9微处理器为硬件平台,向动力驱动装置,即伺服电机和步进电机驱动器提供控制信号,控制铣刀的旋转和走位的嵌入式数控铣床控制系统的实现方案。经实验表明,系统在较好地满足传统数控铣床系统功能要求的前提下,大大降低了成本,节约了资源。     

Design parameter study of a permanent magnet biased magnetic actuator for improving stiffness and linearity

This paper presents a study on the design parameters of a permanent magnet (PM) biased magnetic actuator (MA) for improving stiffness and linearity of the system by using a dimensional analysis. To reduce the number of parameters and to generalize the results for similar systems, the design parameters were non-dimensionalized by significant variables characterizing the system. For the study, a 1-DOF PM-biased MA was built and the magnetic circuit model including leakage paths and core material reluctances was set up. The dimensional analysis shows that the dimensionless permanent magnet thickness is the key parameters for the linearity of the magnetic force and constancy of coil inductance and PM magnetic flux and that the non-dimensional leakage resistance is a main factor for the bound of the efficiency and the linearity.