一种新型三维微位移工作台的设计和分析

为了解决微位移工作台的三维耦合问题,设计了一种驱动器固定的三维无耦合微位移工作台.本文介绍了它的结构和工作原理,通过有限元分析计算和样机实测验证,分别在X方向,X、Y方向和X、Y、Z方向施加载荷时,三维微位移工作台在X方向的位移不变,解决了三维空间运动耦合问题;分别在X、Y、Z方向施加不同载荷时,得到了工作台X、Y、Z方向的刚度,验证了工作台的位移、最大等效应力与载荷成正比.样机实测结果与有限元计算结果相吻合,工作台符合设计要求.     

动态不确定度的估算方法和应用实例

提出动态校准结果的动态不确定度,并说明其物理意义、估算方法和步骤。并给出对压力和力两种传感器的多次动态校准结果以及估算其动态不确定度的应用实例。     

笔记本电脑的动力学分析与减振设计

对某型笔记本电脑的显示屏结构系统建立有限元模型，基于模态分析和瞬态响应分析结果．找到了影响显示屏余振的主要因素，通过修改相关结构参数，使余振得到有效抑制。动态测试与分析的结果与数值计算结果符合得很好。     

车载平台刚体动力学模型分析

车载火控系统平台装置主要包括光束控制系统、激光器和支撑平台。将整个系统视为刚体,建立刚体动力学模型,并主要对平台在地基的各种振动激励,激光器的脉冲振动以及光束控制系统在力矩、加速度的荷载下进行计算分析．     

基于图像印刷技术的滤波器分析与设计

依据数字图像处理基本原理,针对现实中高斯噪声、椒盐噪声和乘性噪声,设计了一个基于FPGA的专用数字滤波器系统.该系统能对3种典型噪声进行有效滤除,同时该滤波器的性能可通过修改相应参数予以实时调整,通过实验和仿真证明该方案行之有效.     

Estimation and Validation of Semiparametric Dynamic Nonlinear Models

An approach for measurement-based modeling of nonlinear devices is proposed. The method that is commonly used for linear time-invariant systems, namely, parametric modeling and nonparametric verification, is hereby extended to a class of nonlinear systems. The applicability of the method is illustrated on the baseband modeling of a radio-frequency amplifier over a wide power and frequency range.     

数字化可视人体的构建技术与应用研究

数字化可视人体，或称虚拟可视人体，是根据人体解剖学研究的全部数据综合构成的一系列数字化三维图像，而且可以虚拟地进行人体的一切生理活动。这种数字化可视人体可用于进行医学教学、模拟临床手术和放射治疗等，效果显著。本文阐述了制作方法和主要用途。     

Optimization Technique for Design of Automotive Air Filter Housings with Improved Fluid Dynamic Performance and Filtration

A filter housing design technique has been developed that computes the housing geometry required to provide a user-specified velocity distribution through the filter. Appropriate control of the flow field across the filter can improve filter efficiency. Two-dimensional computational designs have been performed specifying a uniform velocity distribution through the filter. This distribution corresponds to a uniform, constant pressure drop across the filter from the upstream to the downstream side. A computational optimization method is used to minimize the variation in the pressure drop along the filter by changing the geometry of the upper wall. Computational fluid dynamics (CFD) calculations of the viscous laminar flow upstream and downstream of the filter are performed using two-dimensional Navier-Stokes equations. As the upper wall profile is numerically changed, the CFD solution for the computations is repeated and the pressure drop variation is reevaluated until an optimum configuration is achieved. The optimization results have produced a pressure distribution that is very close to the specified uniform distribution. Experimental verifications were performed using a laser Doppler anemometer to measure the velocity distribution just upstream of the filter and a pressure transducer to measure pressure drops across the filter. The velocity distribution in this (optimized) housing is more uniform than other housing models having the same fundamental rectangular geometry.     

一种新型电磁能量选择表面结构设计与仿真分析

电磁干扰是通信系统在可靠性及设备安全性中必须考虑的因素,近些年迅速发展的高功率电磁脉冲对雷达天线等通信设备造成严重的威胁.提出一种新型电磁能量选择表面(ESS),该表面在十字形ESS的基础上增加了4个金属枝节,通过单元间加载PIN二极管获得自适应特性.在枝节处加载二极管可以在金属网格结构中引入栅格结构,有效增加屏蔽带宽,而且在透波模式下,枝节形成的二维狭缝阵列结构会在高频产生透射共振,使得表面在高频有一个频带使工作信号通过.仿真结果表明,提出的ESS在高功率电磁脉冲作用下会处于防护模式,其-20 dB带宽可达3.4 GHz;正常工作信号作用下ESS处于透波模式,此时表面为频率选择表面(FSS),其在低频和高频各有一个工作频带,低频部分带宽为0 GHz~1.3 GHz,高频谐振频率为5.36 GHz,带宽可达150 MHz.     

一种新的二维光正交码的设计与性能分析

针对二维光码分多址(OCDMA)系统地址码,本文在单重合序列(OCS)的基础上,构造了一种新的二维光正交码EQC/OCS.该地址码是以扩展二次同余码(EQC)为时间扩频伪随机序列,以OCS或截短OCS为波长跳频伪随机序列进行构造的.与EQC/PC相比,EQC/OCS的波长数可以是任意整数,不局限于素数.EQC/OCS不仅构造灵活,而且充分利用了系统的有效波长资源.当二维OCDMA系统的有效波长数不是素数时,在相同码长和码重的情况下,EQC/OCS增加了二维OCDMA系统的码字容量,从而增加了接入用户数.另一方面,与EQC/PC相比,EQC/OCS的码字的自相关和互相关限保持不变.     

轻型机器人本体样机设计与开发

介绍了国家“九五”科技攻关项目“工业机器人产业化开发”中的“机器人本体样机设计与开发”专题的总体设计思想,机器人结构设计特点,以及在机器人制造、调试与测试方面所进行的工作。共设计出HT－10和HT－30两种型号机器人产品,批量生产11台并应用于长春一汽集团轻型汽车后桥弧焊生产线上。     

基于刚体与流体动力学耦合分析的太阳电池阵地面展开仿真技术

用动态网格技术进行刚体与流体动力学耦合计算,研究太阳能电池阵在地面开展的动态过程.该方法可以到捕捉电池阵展开对周围空气介质扰动复杂流场的特性,计算得到的展开时间与实测值吻合,具有较高的准确性.刚体和流体动力学计算采用通用的算法或程序,对电池阵结构形状和展开方式无特殊的假设,能适应不同类型的电池阵展开分析,具有通用性.     

COM技术及其在测试软件设计中的应用

在用实例介绍COM技术的基础上,提出了测试软件设计的COM组件方案.表明了它具有灵活、高效、代码共享、升级方便等优点.     

微机械惯性开关的非线性动力学特性分析与设计

利用倾斜支撑微梁结构大挠度后屈曲的非线性横向刚度,设计了一种新型屈曲式微机械加速度开关．该开关采用倾斜微梁支撑敏感质量块,两折叠梁固定于质量块的上下表面,保证开关动作的方向性．当外界加速度达到设定的阈值时,梁发生屈曲使开关迅速闭合,加速度低于截至门限值时,屈曲微梁弹性力使开关断开．开关设计中分析了气膜阻尼力和触点接触力对系统性能的影响,建立了多力耦合作用下加速度开关系统的动力学模型,并运用数值方法对含有椭圆积分的强非线性系统进行动态仿真分析,开关响应时间低于6 ms,实验表明开关具有良好的闽值特性和接触可靠性,充分证实了屈曲梁结构应用于惯性微感应器件设计的可行性．     

Design, Prototyping, and Analysis of a Novel Tubular Permanent-Magnet Linear Machine

In this paper, we present a new tubular permanent-magnet linear machine with square-shaped cross section and derive its corresponding analytical model by solving Maxwell equations and applying the superposition theorem. The analytical field solution is necessary for obtaining an analytic form of the machine parameters and variables such as the self- and mutual inductances of the windings, the thrust force, and the windings electromotive force (EMF). These provide a valuable tool for tubular machine analysis, design, and optimization. In order to achieve maximum force density, we optimized the design parameters of the proposed machine using the analytical model. We used finite-element analysis and experimental results to demonstrate the validity of the developed analytical model. Again using the Fourier series of the cogging force and its harmonic analysis, in this paper, we introduce two techniques for cogging force reduction in the new tubular linear permanent-magnet machine. The first technique reduces the cogging force due to interaction between the permanent magnets and the stator teeth, and the other reduces the cogging force due to finite length of the armature. These techniques are straightforward, and their implementations in the tubular linear permanent magnet machine with square cross section are easy. We investigated the effectiveness of the proposed techniques in cogging force reduction by 3-D finite-element analysis and experimental measurements.      

Study of TFTC Dynamic Character Calibration Technique

A TFTC (thin film thermocouple) is an advanced thermal sensor that is used for measuring transient temperatures. Because of the TFTC??s high-speed response, the usual calibration instrument and method cannot meet the calibration needs. This article introduces a pulse laser heating method. Dynamic character measurements and system identification are combined. The material of the TFTC is NiCr?CNiSi, and the film thickness is 2 ??m with a ceramic substrate. The transfer function is derived by means of a least-squares solution. In this method under the assumption of an ideal temperature step, there is no strict requirement on a first-order system and the limit of a pulse laser bandwidth. The calibration method introduced in this article resolves the TFTC dynamic character calibration problem.     

双传声器技术测量结构振动响应的理论与实验

本文利用双通道信号分析仪与微机的联机系统,开发了双传声器测振技术.从理论上研究了该方法的测量误差,做了同加速度拾振方法的对比实验.结果表明:它不失为一种有效的测振方法.     

Nondestructive Estimation of Remaining Fatigue Life: Thermography Technique

A technique for the estimation of remaining fatigue life (RFL) of metallic specimens when subjected to cyclic load is presented. The procedure includes evaluation of thermal response of the metal and its correlation with the fatigue life. Results are presented for a series of fully reversed fatigue tests with Stainless Steel 304L at room temperature. It is demonstrated that the slope of temperature rise as a function of time is a good candidate for estimation of RFL. Once the temperature slope is measured, the remaining useful life of the specimen can be effectively estimated.     

新的多孔泡沫镍制备工艺

针对目前泡沫金属制备方法的缺点,提出了一种泡沫金属制备的新方法——电解液喷射沉积法。研究了喷射沉积制备泡沫镍的工艺,自行研制了试验装置,制备了具有不同孔隙率的泡沫镍试样,分析了相关工艺参数(电解液成分、电流密度、电解液喷射速度等)对泡沫镍微观结构的影响。结果表明:采用相对较低的镍离子浓度配方Bath A对制备均匀致密的枝晶多孔结构有利。随着电流密度的提高,泡沫镍的孔隙率逐渐降低;随着电解液喷射速度的提高,泡沫镍的孔隙率逐渐增加。总体上采用电解液喷射沉积法制备的泡沫镍的孔隙率在30~70%之间。     

机械系统动态优化设计的灵敏度分析法

本文用变分法理论,统一给出了机械系统动态优化设计中需要的伴随方程、末端条件和灵敏度系数公式。方法统一,形式规范。最后给出了两个实例计算。