基于嵌入式的工业控制人机界面系统研究

针对工业控制系统网络化和良好人机交互性的需求,构建和开发了基于ARM9微处理器的通用工业控制人机界面系统。硬件部分主要讨论了以S3C2440微处理器为核心的硬件电路设计,外围电路模块包括SDRAM及Flash存储器电路、以太网电路、RS-232/RS-422电路、触摸屏及LCD接口等电路,在分析了硬件系统信号完整性的前提下,完成了6层PCB的设计工作。软件部分主要研究了U-Boot移植和内核裁剪技术,编写了相关的硬件设备驱动程序,设计了基于QT/Embedded的人机界面和相关应用程序。论文研究最终实现了工业控制系统的人机交互和控制需求。     

基于ARM Cortex-M4的构件化汇编框架的研究

规范易用的汇编框架与样例是微处理器深层次应用开发的基础,但汇编编程复杂,并且目前针对32位ARM Cortex-M4的汇编程序资料和样例程序非常匮乏,学习难度大,开发工作困难重重。在深入分析ARM Cortex-M4汇编指令系统和寻址方式的基础上,以NXP半导体公司发布的Kinetis K(KK)系列MCU为蓝本,根据软件工程思想和构件设计理论,提出层次架构的工程框架建模思想,并构建基于ARM Cortex-M4内核的构件化汇编框架,据此制作GPlO驱动构件。指示灯闪烁样例工程的设计及测试结果表明了汇编框架规范、实用、易用,能降低嵌入式汇编语言的学习难度。框架能为业界基于ARM Cortex-M4的汇编开发提供参考。     

基于ARM Cortex-M3微控制器与QDUC的嵌入式激励器设计

为解决传统激励器设备体积大、成本高等问题,采用ARM Cortex-M3微控制器与QDUC方案设计了一种嵌入式激励器;系统基于ARM Cortex-M3微控制器、以太网PHY与uIP TCP/IP协议栈构建有线以太网实现与外部上位机之间的数据的收发,使用专用QDUC集成电路芯片对以太网传送来的基带数据进行正交数字上变频,产生任意波形射频激励信号。该方案具有环境适应性强、尺寸小、结构简明、开发难度低、工作稳定可靠、可扩展性强等特点。试验实测系统工作于UDP模式时最大可用基带数据更新速率可达21.5Mbps,输出射频信号载波频率覆盖DC～400MHz,满足实际工程需求。     

基于ARM Cortex-M3的声磁商品电子防盗系统设计

针对普通EAS系统存在抗干扰性能差、检测灵敏度低、检测范围小、误报率高等缺点,设计了一种基于ARM Cortex-M3的声磁EAS系统。本文介绍了声磁EAS系统的工作原理和硬件结构框图,分析了声磁标签信号在时域和频域上的特征,提出了FFT信号频谱分析、信号互相关、最小二乘法拟合直线求取斜率、计算信号峰值数及峰值方差运算等多种检测声磁标签信号的算法,并详细描述了系统软件算法的设计。实验验证,本系统具有抗干扰性能强、检测灵敏度高、检测范围宽、误报率低等特点。     

基于ARM9的通用IPMC载板设计

针对ATCA构架体系中由IPMC没有完全按照规范要求设计而引发的兼容性差的问题,提出一种基于ARM 9的通用IPMC载板设计方案;该方案以ARM 9嵌入式微处理器为核心,设计了合理的硬件电路,符合PICMG 3.0规范和IPMI 2.0标准,可以适应各种背景的ATCA板卡管理;选取Radisys机箱作为实验平台,IPMC载板可以实现对ATCA板卡的管理并且与机箱管理进行可靠通信,有效验证了载板的可行性和通用性;通过将载板搭载在不同的FRU上进行实验,结果证明载板具有良好的兼容性。     

基于ARM嵌入式Linux的数据采集系统设计

针对传统数据采集系统的不足,文中介绍了一种基于ARM9的数据采集系统的设计原理和实现方法。以微处理器S3C2440A为核心,外扩高精度A/D芯片AD7606,设计了数据采集硬件电路,分析了AD7606和PWM定时器的基本工作原理,借助于移植的嵌入式Linux操作系统,实现了基于PWM和GPIO口的ADC驱动及相应的数据缓冲与软件抗干扰。测试结果表明,由ARM和Linux组成的数据采集系统具有操作方便、采集精度高和测量结果准确等优点。     

基于HART协议的二线制涡轮流量变送器的开发

以HART协议为通信标准,提出了系统的总体方案设计,通过对HART协议的理解与掌握,详细的给出了基于涡轮流量变送器的软硬件设计;硬件设计部分包括涡轮脉冲采集模块,微处理器模块,HART通信模块和4~20 mA环路电流模块4个模块,其中HART通信模块采用HART调制解调器芯片AD5700实现,4~20 mA环路电流模块采用环路供电专用芯片AD5421实现,二者共同构成了HART协议的物理层接口,文章硬件电路所采用的都是低功耗芯片,用纯硬件的方法解决了HART总线设备的低功耗难点;软件设计部分包括主监控程序、变送计算程序和HART协议通信程序3个程序模块,重点讲述了HART协议的数据链路层和应用层的实现过程;最后文章对涡轮流量变送器的二线制传输功能和HART通信功能进行了测试;测试结果表明,变送器的设计要求基本实现了。     

无人飞行器飞控测试中动力故障自主检测系统设计

针对无人飞行器动力推进装置容易发生故障而造成飞行器发生事故的问题,提出基于ARM微控制器飞行控制平台构建无人飞行器动力故障自主检测系统,介绍了系统设计的组成与总体结构,研究实现了ARM微控制器LPC2148的硬件连接电路,PWM 信号发生电路,A/D 采样电路及前置放大电路等;对系统硬件平台进行了启动代码等系统底层软件的设计,对自主检测算法进行了研究,建立了系统的启动环境;并通过飞控测试对系统进行了调试,测试中通过PC上的串口软件,设置串口为C0M1,波特率为115 200,校验位为NONE,数据位为8,停止位为1,发送和接收均为16进制显示,实验结果表明系统对于无人飞行器动力故障自主检测的准确性与稳定性均有很大提高。     

基于STM32的简易数字示波器设计

随着科学技术的发展,示波器已成为电路调试测试的必备仪器之一,其发展速度和应用远超其他测量仪器。本设计完成基于Cortex-M3内核单片机设计的数字示波器,硬件电路设计主要包含STM32F103RCT6单片机最小系统、信号调理电路、TFT液晶屏显示电路、按键电路,电源电路;软件设计主要包含模数转换处理编程、TFT液晶屏波形显示编程、按键功能控制编程和数据算法处理编程^[1]。系统信号调理电路将输入信号衰减、限幅、叠加,最后输入单片机自带的模数转器中,将模拟量转换为数字量,最后经过单片机转换处理,通过液晶屏将采集到的波形信号显示出来。系统设计具有功耗低、体积小、成本低等特点,具有一定的应用前景和研究价值。     

基于STM32与串口服务器的IP语音通信系统设计

针对模拟训练系统中语音通信的应用需求,提出了一种基于TCP/IP协议在局域网内进行IP语音通信的实现方法。分析了该语音通信系统的组成结构和工作原理,设计了以微处理器STM32F103ZET6为核心、以语音编解码芯片VS1053B为驱动的语音控制电路,SD卡连接电路和电源电路;移植了UCOSⅢ嵌入式实时操作系统增强控制系统的实时性和稳定性,采用FatFs文件系统管理SD卡存储设备。利用串口服务器实现串口数据与以太网数据的快速交换,完成模拟训练系统局域网的搭建,实现基于TCP/IP协议的稳定高效的IP语音通信。测试结果表明,系统稳定可靠、扩展性强,语音通信质量满足模拟训练使用要求。     

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.     

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.     

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.     

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.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.     

A stereo matching algorithm using multi-peak candidate matches and geometric constraints

Gray cross correlation matching technique is adopted to extract candidate matches with gray cross correla- tion coefficients less than some certain range of maximal correlation coefficient called multi-peak candidate matches. Multi-peak candidates are extracted corresponding to three closest feature points at first. The corresponding multi-peak candidate matches are used to construct the model polygon. Correspondence is determined based on the local geometric relations between the three feature points and the multi-peak candidates. The disparity test and the global consistency checkout are applied to eliminate the remaining ambiguous matches that are not removed by the local geometric relational test. Experimental results show that the proposed algorithm is feasible and accurate.