Networked telemicromanipulation systems "Haptic Loupe"

In this paper, "Haptic Loupe" telemicromanipulation systems are proposed. We have developed telemicromanipulation systems that enable human operators to perform micro tasks, such as assembly or manufacturing without stress . These systems are based on a scaled bilateral teleoperation system between different structures. The systems are composed of an original six-degrees-of-freedom (6-DOF) parallel link manipulator to carry out micromanipulation and a 6-DOF haptic interface with force feedback. A parallel mechanism is adopted as a slave micromanipulator because of its good features of accuracy and stiffness. The haptic master interface is developed for micromanipulation systems. Haptic device system modeling and a model reference adaptive controller are implemented to compensate for friction forces, which spoil the free motion performance and force response isotropy of the system. Total system performance as a telemicromanipulator system is evaluated by performing some primitive manipulation tasks in a teleoperation experiment. Experimental results are presented and discussed.     

Wide-Area Protection and Power System Utilization

This paper describes basic principles and philosophy for wide-area protection schemes, also known as remedial action schemes (RAS) or system protection schemes (SPS). In the areas of power system automation and substation automation, there are two parallel trends in different directions: centralization and decentralization. More and more functions are moved from local and regional control centers toward the central or national control center. At the same time we also observe more and more "intelligence" and "decision-power" moving closer toward the actual power system process. We also see a great deal of functional integration, i.e., more and more functionality enclosed in the same hardware. This raises discussions concerning reliability (security and dependability). The main targets for this paper is therefore to: 1) sort out the terminology used in this area; 2) describe different application areas and related requirements; 3) illustrate different design principles-"top-down", "bottom-up", hierarchy, flat, etc., for different applications; and 4) identify similarities and differences between classic equipment protection and system protection-concerning philosophy as well as concerning product and system design. The theme of the paper is on the use of information technology to obtain more flexibility and smartness in power-system controls.     

Design of a novel visual and control system for the prevention of the collision during the micro handling in a SEM chamber

This paper presents a video system for preventing a collision of the micro gripper and the stage on which the micro component is located during micro manipulation in the chamber of a scanning electron microscope. This system consists of a micro manipulation station, micro camera with magnification lenses and a reflective specimen stub. Special focus is given to the approach procedure of the micro gripper toward the micro component, a sequence that is crucial during a micro manipulation process. A new control program which replaced the original manual control of the micro manipulation station enables improved system performance, especially fine adjustment, positioning and manipulation.     

基于压电驱动的靶球筛选操作机理及实验研究

针对惯性约束聚变中靶球筛选操作的粘着问题,提出一种基于压电驱动控制的微操作方法,并结合微机电系统(MEMS)技术和微驱动方法,研制压电驱动操作模块用于实验研究.首先,分析微尺度对象粘着机理并进行粘着接触模型的建立,并在此基础上提出对操作工具施加振动,利用惯性力作用克服粘着力的动态操作方法;同时,结合靶球筛选操作的特点,分析操作控制策略;最后建立了基于压电驱动的微操作实验系统.针对直径Φ50～400 μm的靶球对象进行操作实验,成功实现了靶球样品的高效、准确拾取和释放,拾取和释放成功率大于90％.     

聚焦离子束系统原理、应用及进展

聚焦离子束纳米加工系统,具有传统加工工具无可比拟的优势而逐渐成为新一代微纳分析、加工的工具在微纳米加工、操纵以及器件的研制等方面具有重要应用.本文介绍了聚焦离子束系统的内部结构和工作原理,探讨了该系统的扩展功能、应用及发展前景.     

倒锥微孔阵列的激光微加工技术研究进展

激光微加工技术凭借其加工效率高、加工材料广泛、无物理损伤以及操控性强等优点在高精度机械部件的加工上有较好的应用前景,易加工出尺寸微小、数量庞大、高品质的倒锥微孔阵列.首先对激光加工微孔的工作原理和特点进行了介绍,综述了激光在加工微孔阵列、倒锥微孔以及倒锥微孔阵列的研究现状,详细介绍了准分子激光、飞秒激光、纳秒激光在加工...     

浅谈微课在《电工电子技术》课程中的应用

在互联网时代,为了满足学生碎片化学习的需求,微课成为教师进行教学工作的重要辅助手段。微课的开发和广泛使用一方面能够将难以理解的知识通过视频的方式展现在学生面前,另一方面也满足了学生在任何时间、地点进行学习的需求。微课在《电工电子技术》课程中的应用,能够极大的提升教学效果,提高学生学习的积极性和主动性。     

浅论基于光纤通信的智能配电网通信技术

本文介绍了智能配电网的概念、智能通信网的特点,重点论述了工业以太网交换机和以太网无源光网络(Etherent Passive Optical Network,EPON)的原理和系统结构的异同,以及它们的应用.     

飞秒激光双光子聚合加工微纳结构

针对微/纳机电系统（MEMS/NEMS）零部件加工制造难题,研究具有亚衍射极限空间分辨率的飞秒激光双光子聚合加工方法,搭建钛蓝宝石飞秒激光微纳加工系统,对液态聚合物材料进行飞秒激光双光子聚合加工工艺试验研究。结果表明:随着激光功率的降低,单个固化点的尺寸减小,加工分辨率提高;扫描步距减小,所加工工件的表面粗糙度数值减小,但加工效率降低。基于CAD软件设计出微米墙和纳米线构成的三维微纳结构,利用飞秒激光双光子聚合加工得到该三维微纳结构实物,通过优化工艺参数加工出直径小于100 nm的纳米线,从而证明飞秒激光双光子聚合加工方法为微/纳器件的制造提供了一种有效方法。     

微能源发展概述

产品小型化、微型化、集成化是当今技术发展的大趋势,能源供应已成为制约产品微型化技术发展的瓶颈,其微型化问题受到广泛的重视。结合目前国内外微能源的发展现状,分别介绍了微太阳能电池、同位素微能源和基于卡门涡街的压电微能源等几种典型的微能源,并展望了微能源的发展趋势和应用前景。     

Novel Micro Fourier Transform Spectrometers

The miniaturization of spectrometer opens a new application area with real-time and on-site measurements. The Fourier transform spectrometer （FTS） is much attractive considering its particular advantages among the approaches. This paper reviews the current status of micro FTS in worldwide and describes its developments; In addition, analyzed are the key problems in designing and fabricating FTS to be settled during the miniaturization. Finally, a novel model of micro FTS with no moving parts is proposed and analyzed, which may provide new concepts for the design of spectrometers.     

浅谈"创新型"课题QC小组

本文针对"创新型"QC小组的活动特点,思维方法,"创新型"课题QC小组与"问题解决型"课题QC小组的区别及开展"创新型"课题活动应注意的问题等方面进行了具体阐述.     

MIM shunt-capacitor model using black boxes of EM-simulatedcritical parts

A new model for metal-insulator-metal shunt capacitors is introduced in this paper. The main difference between the new model and known models is that critical parts of the capacitor's geometry are represented by black boxes. These boxes contain S-parameter files generated with an electromagnetic field solver. The capacitor parts, which depend on the capacitance value, are represented by microstrip and lumped elements. The new model combines the advantages of field simulations with those of lumped- or microstrip-based models. It can easily be used in circuit simulators utilizing their features for design development such as optimizations. The model is compared with two shunt capacitors on microwave monolithic integrated circuits to show the excellent fit     

微纳操纵成像系统的线性自抗扰控制器设计

针对比例积分(PI)控制微纳操纵成像系统存在控制精度低、抗干扰能力弱等问题,提出了一种基于线性自抗扰的控制方法。该文分析了微纳操纵成像系统的结构及数学模型,并设计了线性自抗扰控制器,利用所得模型的参数,确定带模型信息的线性扩展状态观测器的部分参数和PI控制器的参数。在Matlab/Simulink中搭建控制器模型,并进行仿真实验的对比。结果表明,该研究与传统PI控制相比,具有控制精度高,抗扰能力强等特点,有效改善了系统的性能。     

移动Ad Hoc网络中MAC协议的研究分析

移动Ad Hoc网络是随着无线通信技术的快速发展而出现的一种新型网络。由于Ad Hoc网络自身的特殊性,使得其媒体接入控制协议(MAC)与传统的有线局域网、无线局域网以及蜂窝网络有很大的区别。首先对移动Ad Hoc网络进行了介绍,分析了移动Ad Hoc网络MAC协议设计面临的问题,对当前较常用的Ad Hoc网络MAC协议进行了分析比较,为进一步对MAC协议的研究提出了新的课题。     

独立源和受控源的异同点

“电路基础”对于高等学校电类专业学生来说,是一门重要的学科基础课,其中受控源是基础知识部分的一个难点,本文从受控源和独立源的定义出发,结合思维导图,在是否为激励源、端口情况、等效电路和在叠加定理的应用四个方面深入分析了受控源和独立源的不同之处,从“源”的角度阐述受控源和独立源的相同点,同时分别给出了四种受控源的原型电路实例,分析了受控源供出能量的来源,旨在为学习者深刻理解受控源提供帮助。     

Hardware vs software maintainability: A comparative study

The rapid technological advances in microelectronics, microprocessors and computer science, accompanied by the increasing use of digital techniques in system designs, have resulted in a transition of system problems from hardware to software. Software costs now generally exceed hardware costs. The use of the words reliability and maintainability for software are taken in a completely different context than for hardware. Significant differences exist between hardware R & M (reliability and maintainability) and software R & M in the basic concepts, understanding, principles, analytic models and design techniques used. Some recent papers 1., 5., 9. point out some of these differences with respect to reliability. This paper discusses hardware and software with respect to maintainability, to point out their similarities and differences in both conceptual and practical terms.     

微小卫星技术发展及其应用

本文在探讨现代微小卫星技术发展应用的同时,介绍了清华大学在微小卫星方面的技术研究,特别是清华大学与英国SURREY大学合格研制的“航天-清华I号”微小卫星技术,包括数据接收、处理和传输实验载荷技术、星上数据处理及高效数据传输技术等。另外,针对清华大学宇航技术研究中心“十五”期间在微小卫星技术方面的研究设想作简要介绍。     

A probabilistic approach to evaluate the reliability of piezoelectric micro-actuators

In this paper, a probabilistic design approach is presented to evaluate the reliability of piezoelectric micro actuators. Based on the relationship between the lifetime, and degradation mechanism of piezoelectric actuators, and the electric field strength, the concept of "electric strength" is proposed to indicate the electric field strength of the piezoelectric actuators at a specified lifetime. The lifetime (number of cycles to failure) of the piezoelectric actuator, electric strength, and electric load are considered as the random variables; and their probability distributions are discussed. The interference model of electric load, and electric strength is introduced to the reliability design of piezoelectric micro actuators. By this approach, the relationship between the reliability, and the lifetime of the piezoelectric actuator can be given. A case study of the disk drive head positioning system demonstrates the application of the approach.     

微生化芯片内光探测的研究

针对微生化芯片样品量少、需要与微流体芯片集成等要求 ,设计了两种在芯片内用分光光度法 ,对混合后液体的吸收光谱进行探测的方法。光探测部分是微型生化分析芯片的重要组成部分。原理性实验利用 4 6 0～ 80 0nm的可见光光源 ,采用了直接探测法和消逝波探测法对样品进行探测。通过两种方法的比较证明 :直接探测法具有原理简单、实验效果明显等优点。利用消逝波探测具有易于集成的优点