转盘式测试分选机主电机高精速定位控制研究

针对转盘式测试分选机中主电机进行高精速定位控制技术研究,以雅科贝思的ATR152-138电机为研究对象,电机采用矢量控制策略,对其及其负载建立数学模型,并讨论了伺服控制位置闭环、速度闭环以及电流闭环中3个控制器的工程设计方法。仿真结果证明转盘上主电机调节器设计合理,位置和速度响应非常快,满足测试分选机的要求     

HL-2A的中央逻辑控制PLC环网设计

PLC逻辑控制是HL-2A中央控制系统的重要组成部分,改造前的逻辑控制系统基本使用硬连接,维护耗时耗力。结合新一代实时工业以太网PROFINET为HL-2A逻辑控制系统的改造设计了环形冗余网络。采用8台西门子交换机SCALANCE X200通过光纤依次连接成环,交换机的电口连接S7-400和上位机,与等离子体放电相关的重要信号仍走硬连接,其他所有信号都走网络传送。中控系统作为管理站对其他7个子系统进行集中化管理,中控可以轻松快速地获取每个子系统的状态,在等离子体放电错误时能很快的预测事故地点和故障分析。根据放电实验结果表明,光纤环网非常适用于设备分散的慢控制系统,整个控制系统逻辑关系清楚,后期扩展和改造也非常方便。改造后的逻辑控制系统能满足HL-2A和HL-2M两套装置的慢控制,维护简便,事故定位快准,提高了放电效率。     

液压驱动四足机器人控制系统开发

针对液压驱动四足机器人的结构特点和自动化运动需求,设计基于CAN总线通信的分层式控制系统,分为远程监控层、规划控制层和执行控制层三层,并按照控制系统总体设计方案进行硬件系统和软件系统开发;该控制系统应用基于WINDOWS的PC机和基于ARM开发的触摸操控板进行远程监测和控制,采用基于QNX的PCI/104单板机对机器人的运动进行规划,选用DSP作为执行机构处理器,从而构建了一个具有工作性能稳定、实时响应快、结构紧凑等特点的控制系统平台;软件系统采用模块化设计的思想进行开发,提高了控制系统的扩展性;最后,通过对液压缸运动的控制实验,验证了该控制系统的稳定性和可靠性。     

用于空间通信的小型化高功率低噪声光纤放大器

针对空间应用设计了结构紧凑、高功率、低功耗的光纤放大器.在电学设计上,以数字信号处理芯片为核心处理器设计了泵浦源驱动控制系统,形成了输出-检测-再输出的闭环控制逻辑,通过自动功率控制保证输出稳定性,同时降低泵浦源功耗,提升电光效率.在机械设计上采用光电分离模块化设计,不仅有利于散热和保持紧凑的结构,而且实现光学部分与电...     

基于51单片机的边界扫描控制器的设计与实现

为提高现代军事装备的故障检测能力,运用VC++软件编辑控制界面,设计并制作了一种基于51系列单片机的边界扫描控制器;该控制器由USB转串口电路和单片机构成,结构简单、通用性强且成本低廉;将PC机发送的测试指令或数据进行USB与JTAG协议转换,产生符合IEEE1149.1标准的JTAG总线信号;以EPM7128芯片为测试对象,注入JTAG信号并采集测试响应,实现了对基于测试芯片硬件电路的故障检测;测试结果表明:设计的边界扫描控制器可实现对单芯片和芯片级联的边界扫描状态的控制,能避开可编程芯片的内部逻辑程序控制,完成对可编程芯片及其外围电路的故障检测。     

基于DSP＋USB2．0的激光雕刻切割机高速数据传输的研究

采用高速DSP芯片TMS320F2812和USB2．0接口芯片CY7C68001来解决激光雕刻切割机控制系统数据传输中的低速问题。介绍了系统的硬件连接及软件实现。通过实际测试证明，USB2．0接口的实际数据传输速度最高可达200Mbps，完全可以满足激光雕刻切割机控制系统高速、实时传输的要求；同时利用USB总线对整个系统进行了有效地扩展。     

飞机起动箱自动测试设备研制

起动箱是飞机发动机起动电气控制系统的核心部件,控制起动附件按照时序逻辑协调工作来起动发动机;对起动箱的组成和控制时序逻辑进行了具体分析,基于ATE硬件平台设计了起动箱的自动测试电路,采用了总线程控仪器和图形化测试软件等技术,实现了不同工作电压下起动箱的电子定时机构通断时间参数、起动程序线路时序逻辑功能的自动测试和故障诊断功能;经部队使用表明,该设备测试效率高,测试精度高,自动化程度高,人机交互界面友好,操作简单。     

PLC激光时序控制系统的研制

激光时序控制系统采用计算机（以下称PLC—k位机）和PLC相结合的方式，如图l所示。整个系统的结构分为三层：系统管理层、PLC控制层、分系统控制层或现场执行机构。系统管理层完成时序控制系统的任务设定、信息显示、状态监测、故障报警、数据处理和通信等功能，由一台工业控制计算机实现。该层与PLC之间通过以太网通讯，遵循TCP／IP协议。PLC控制层直接与各个分系统连接，完成时序控制，是激光时序控制系统的关键。这个层次的PLC模块主要完成数据采集、时序控制等任务。分系统控制层执行指令动作，并把必要的信息反馈给PLC控制层。     

双核SoC芯片扫描链测试设计与实现

针对芯片生产过程中可能引入短路和断路等制造缺陷的问题,实现了基于扫描链测试的双核SoC芯片可测性设计电路。根据双核SoC中DSP硬核、CPU软核特点采用不同的扫描链设计方案：利用DSP硬核中已有扫描链结构,将DSP测试端口复用到芯片顶层端口,在CPU软核和其它硬件逻辑中插入新的扫描链电路。扫描链测试支持固定型故障测试和时延相关故障测试。针对时延故障测试,设计了片上时钟控制电路,利用PLL输出高速时钟脉冲进行实速测试。采用自动测试向量生成工具产生测试向量,结果表明,芯片固定型故障的测试覆盖率可以达到97.6%,时延故障测试覆盖率可以达到84.9%,满足芯片测试覆盖率要求。     

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介绍了J-TEXT装置上将用于辅助加热研究的一套100kV/60A高压电源。这套高压电源基于PSM技术设计,由144个开关电源模块构成。为了满足隔离、控制和保护的要求,采用PXI和FPGA技术设计了符合CODAC规范的PSM电源控制系统,并提出改进的PSM控制策略实现对高压电源的控制。为验证控制系统的性能,在由8个模块组成的高压电源模型样机上对控制系统进行了测试,测试结果表明,系统各项性能良好,可以满足100kV/60A高压电源的控制要求。     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Research on beamforming method for dual-line array with space mismatch between the two line arrays

The performance of port/starboard discrimination of dual-line array will be seriously degraded when the space between the two line arrays of the dual-line array is mismatched. The directivity function of the delay-sum and delay-subtract beamforming is deduced and the port/starboard discrimination of the delay-sum and delay-subtract beamforming is also studied both under the ideal status and the status under which the space between the two line arrays of the dual-line array is mismatched. Analysis results show the delay-subtract beamforming has better performance of port/starboard discrimination. At last, the sea trial results demonstrate the theoretical results.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Retrieval of ultraviolet skylight radiances and O3 slant column densities from balloon-borne limb spectrometer

With a novel light-weight and absolutely calibrated ultraviolet （UV） spectrometer, UV skylight radiances and O3 slant column densities are measured by balloon-borne limb measurements in Xinjiang area, China. UV skylight radiances measured at the height of 31 km are compared with the results from Modtran in the wavelength range from 290 to 420 nm. O3 slant column densities are derived from radiance spectra in the Huggins bands （320 - 335 nm） using differential optical absorption spectroscopy method. And the parameter exhibits a good correlation with the same value simulated by radiative transfer model （Tracy）. The O3 profile simultaneously measured by an O3 sonde is used as input in Tracy calculations. The O3 sonde is launched on the same balloon.     

Design optimization of highly sensitive LSPR enhanced surface plasmon resonance biosensors with nanoholes

For breaking through the sensitivity limitation of conventional surface plasmon resonance (SPR) biosensors, novel highly sensitive SPR biosensors with Au nanoparticles and nanogratings enhancement have been proposed recently.But in practice, these structures have obvious disadvantages.In this study, a nanohole based sensitivity enhancement SPR biosensor is proposed and the influence of different structural parameters on the performance is investigated by using rigorous coupled wave analysis (RCWA).Electromagnetic field distributions around the nanohole are also given out to directly explain the performance difference for various structural parameters.The results indicate that significant sensitivity increase is associated with localized surface plasmons (LSPs) excitation mediated by nanoholes.Except to outcome the weakness of other LSP based biosensors, larger resonance angle shift, reflectance amplitude, and sharper SPR curves' width are obtained simultaneously under optimized structural parameters.     

Polymer gratings based on photopolymerization for low-order distributed feedback polymer lasers

Novel polymer distributed feedback(DFB)gratings are fabricated based on photopolymerization to reduce lasing threshold of polymer lasers.A photopolymer formulation sensitive to 355-nm ultraviolet(UV)light is proposed for the fabrication of polymer gratings and it can be used to form polymer films by spin-coating process.A very low surface-relief depth ranging from 12.5 to about 1.0 nm has been demonstrated with a refractive-index modulation of about 0.012.The experimental results indicate that such polymer gratings have promising potentials for the fabrication of low-order DFB organic semiconductor lasers.     

A novel methodology for photometric compensation of projection display on patterned screen

We propose a novel methodology based on the projector-camera (ProCam) system to address the photometric compensation issue for the projection display on the patterned screen.The patterned screen is treated as the combination of a perfect white screen and a color modulator.The perfect white screen is used to automatically and accurately characterize the ProCam system offline using the polynomial model,and the parameters of the color modulator can be efficiently recovered by employing only two gray images based on the linear reflectance model.The experimental results show that the color artifacts of the display image can be greatly improved with this methodology,which demonstrates its feasibility and validity in the photometric compensation.