一种采用微处理机控制的激光微光束测量系统

本文介绍了一台以Z-80微处理机为主机的光强数据采集系统,并将它用于激光微光束的半径测量。对于微米量级的光束,测量误差为1％。     

Quasi-peak detector model for a time-domain measurement system

In this paper, a quasi-peak detector mode for a time-domain electromagnetic interference (TDEMI) measurement system is described. Measurements were performed in the 30-1000-MHz range. The digital signal processing of EMI measurements can emulate in real time the modes of conventional analog equipment, e.g., peak, average, rms, and quasi-peak detector. With the presented time-domain measurement system, the measurement time can be reduced by a factor of ten. A novel signal recording routine for TDEMI measurements and quasi-peak detection is described. Measurement results obtained from the investigation of a drill machine, monitor, and laptop obtained with the TDEMI measurement system are discussed. The comparison of the results obtained with the described TDEMI measurement system and measurements performed with a conventional EMI receiver show an average deviation over the whole frequency range less than 3 dB.     

基于位置敏感探测器的微位移测量关键电路设计

位置敏感探测器PSD(Position Sensitive Detector PSD)具有位置分辨精度高(可达1～2μm)、输出实时性好(响应时间约几微秒)、系统简洁的特点,在位置探测及相关领域内获得了广泛的应用;但PSD的输出信号小,易受到电路噪声的影响,若要充分发挥其性能,则需要高精度、高稳定度、低噪声的测量电路。针对PSD这种较高的使用要求,通过对其等效模型的分析,找到了影响位置分辨精度的主要因素,并提出了一种新形式的测量电路,减少了测量电路级数,降低了电路的噪声以及测量电路内部的漂移,同时具有对位置测量非线性的校正功能。采用上述原理以S1880PSD建立的位置测量系统的位置分辨达到2～3μm。     

一种实用化实时测温系统的测温灵敏度

基于基尔霍夫定律,利用半导体激光器InGaAs/I及钽酸锂热释电探测器设计了一种实用化的实时测温系统。基于该系统A/D转换器件的分辨率、V(T)-T曲线的温度灵敏度及其与测温范围间的制约关系,确定了系统应选用16位的芯片为其A/D转换器件;基于该系统的测温精度、V(T)-T曲线的相对温度灵敏度及其与波长间的关系,对其工作波长的优化选择进行了进一步的讨论;基于探头的温度分辨力、A/D转换器件的分辨率以及与V(T)-T曲线的温度灵敏度间的制约关系,对其波长带宽的优化设计进行了进一步的分析,并给出了系统在673K～1473K内的测温灵敏度。对系统进行优化设计后,在测温范围的低温段,其灵敏度不低于0.5K;在测温范围的高温段,则不低于0.1K。在673K～1473K内,其测温不确定度不低于0.3%。     

一种新型实时快速滚转角测量系统

针对滚转角测量系统中的实时快速图像处理需求,提出一种基于泰伯-莫尔效应的计算量小、快速高效并且精度高的图像处理算法。首先,对干涉图像进行频域滤波和空域中值滤波,去除噪声并平滑保留图像边缘;然后采用自适应二值化进行阈值分割,再进行细化并去除毛刺,剪切图像去除效果差的边缘数据;最后采用一种霍夫变换和最小二乘法求解条纹间隔进而求得滚转角。实验结果表明,测量误差小于2.5 arcsec,在PC机上完成一次运算时间约为400 ms。所采用的算法提高了图像处理速度。全部算法采用ANSI C编程实现,可移植到不同的嵌入式图像处理系统中,提高了算法的通用性和实用性。     

基于单片机的超声波测距系统的设计

介绍了利用单片机控制的超声波测距系统的原理，由单片机控制时间计数、控制超声波的发射和接收。给出了系统构成，并在数据处理中采用了温度补偿修正。此系统具有易控制、工作可靠、测量精度高的优点。     

A real-time laser-based detection system for measurement ofdelineations of moving vehicles

In current practice, quantitative traffic data are most commonly acquired from inductive loops. In addition, video-image processing or time-of-flight laser systems can be used. These methods all have problems associated with them. We have developed a nonintrusive laser-based detection system for measurement of vehicle travel time. The basic detector unit consists of a fan angle laser and a photodetector array positioned above the plane of detection. This detection system is able to determine the length and width of moving objects in real time with high resolution, with the highest resolution measurements being associated with object lengths. This information is used to differentiate similar objects and can be used later for re-identification of individual objects or object groups, providing a real measure of travel time between detection sites     

实时测温系统中测温精度的提高措施

在介绍一种利用InGaAs/I半导体激光器实现的实时测温系统的基础上,着重从硬、软两方面研究了在该系统中所采取的提高其温度测量精度的若干措施:一是精选探测器、优化设计调制盘并进行选频放大;二是在调制盘与探测器之间置一窄带滤光片;三是采用水冷遮蔽板并进行电气补偿;四是提高系统的采样精度。进行了一些必要的分析和讨论。     

On-line microwave system for humidity measuring with microprocessor

A sensor with high sensitivity and good linearity, which is suitable for measuring humidity of clastic dielectric on conveyer, is presented. With a microprocessor to sample and process the data, the accuracy is improved. A dynamic experiment with this system was carried out on the conveyer at Shanghai Coking Factory and the results accord with variation regularity of the humidity of choice coal.     

一种实用化实时测温系统的温度分辨力

基于Kirchhoff定律,利用半导体激光器InGaAs/I及钽酸锂热释电探测器设计了一种实用化的实时测温系统。基于系统温度分辨力的要求,对光学系统的相对孔径及选频放大器的带宽进行了优化设计。结合V(T)～T曲线的温度灵敏度和相对灵敏度变化曲线,重新讨论了系统的工作波长。实验结果表明,采用所选择的激光波长和光学系统的相对孔径及选频放大器的带宽,在实际的测温范围内,系统的温度分辨力和V(T)～T曲线的温度灵敏度均能够满足系统要求。     

基于STM32单片机的高精度超声波测距系统的设计

提出了一种基于STM32单片机的超声波测距系统的设计方案。与传统单片机相比,STM32的主频和定时器的频率高达72 MHz,提高了时间测量的分辨率。在开启定时器计时的同时,启动PWM通道驱动超声波发射器和输入捕获通道捕捉回波信号,提高了测量的精度。在充分分析超声波测距产生盲区和误差原因的基础上,设计了时间增益补偿电路(TGC)和双比较器整形电路分别测量远、近距离,并通过软件算法对回波信号进行峰值时间检测,简化了电路。实验研究表明,该系统测量精度达到了1 mm,盲区低至2.5 cm。     

A system for real-time measurement of the brachial artery diameter in B-mode ultrasound images.

The measurement of the brachial artery diameter is frequently used in clinical studies for evaluating the flow-mediated dilation and, in conjunction with the blood pressure value, for assessing arterial stiffness. This paper presents a system for computing the brachial artery diameter in real-time by analyzing B-mode ultrasound images. The method is based on a robust edge detection algorithm which is used to automatically locate the two walls of the vessel. The measure of the diameter is obtained with subpixel precision and with a temporal resolution of 25 samples/s, so that the small dilations induced by the cardiac cycle can also be retrieved. The algorithm is implemented on a standalone video processing board which acquires the analog video signal from the ultrasound equipment. Results are shown in real-time on a graphical user interface. The system was tested both on synthetic ultrasound images and in clinical studies of flow-mediated dilation. Accuracy, robustness, and intra/inter observer variability of the method were evaluated.     

基于晶体管测量的中子注量在线实时测量系统

利用晶体管直流放大倍数的倒数与中子注量呈线性关系这一特点,使用晶体管作为在线中子注量测量的探测器,建立了以计算机、GPIB总线、矩阵开关、任意波形发生器、数字示波器等硬件为基础,基于LabVIEW软件平台的中子注量在线实时监测系统。在西安脉冲反应堆中子辐射场中,开展了标定实验研究,建立的中子注量在线实时监测系统实现了空间分布的中子注量实时测量,利用该套系统得到了XAPR和CFBR-Ⅱ的等效损伤系数。     

A microprocessor system for surveillance of sensors via autoregressive identification

This paper presents an on-line sensor tester based on autoregressive models. The noisy signal delivered by the sensor is analysed as a response of a linear system to a white noise excitation. This model is identified and then used to obtain an estimation of the frequency and step responses of the sensor.After this identification stage, the model and its characteristics are used to determine whether or not the sensor is in working order. This decision concerning the sensor state is taken following statistical criteria.The main part of the paper discusses the theoretical background of the realized device: choice of the model and order determination, model validation, responses calculation and decision on the sensor state. Results of the preliminary study in simulation are shown. Then the hardware and software of the realized device are described as well as the obtained performances.     

深海垂直剖面实时监测系统的设计与实现

为了对深海动力环境进行监测,设计了一种深海垂直剖面实时监测系统。系统利用浮力调节的方法实现测量平台沿系留索升降,在升降的过程中进行海洋剖面参数的测量,同时将测量数据通过感应耦合传输和卫星通信的方式传送给岸站。突破了水下大背压条件下浮力调节技术和海上数据实时通信传输技术,实现了深海动力环境的实时测量。     

An electronical system for real-time measurement of the logarithmic magnitude of scattering parameters

An electronical system for real-time measurement of scattering parameters of millimeterwave two-ports is described. In order to achieve a suitable measurement accuracy, the output signals of the millimeterwave detectors and the characteristic of the measurement amplifier should be matched. For this reason the detector power-characteristic is approximated by help of a polygon and it is realized with a few nonlinear amplifiers. The theoretical background and experimental results show the applicability of the measurement system presented here.     

A NOVEL DETECTOR FOR UPLINK CDMA SYSTEM WITH UNKNOWN INTERFERENCE

In this letter, the detection of asynchronous DS-CDMA signal with multipath fading and interference from neighboring cells is studied. A novel multiuser detector based on Gibbs sampler is proposed, in which Gibbs sampler is employed to perform the Bayesian multiuser detection according to the linear group-blind decorrelator output. Since Gibbs sampler is dependent of parameter estimation that can be improved by the output of the detector, an enhanced Gibbs sampier based detector using the improved parameter estimation is put forward. The novel multiuser detection technique has the advantages of high performance and wide applications. Computer simulations show its effectiveness.     

High performance package designs for a 1 GHz microprocessor

This paper describes the architecture and design of an organic land grid array (OLGA) and a flip chip pin grid array (FCPGA) package for a 32 b microprocessor with a clock frequency of 1 GHz and an I/O bus designed to run at 133 MHz. Cost and performance targets and compatibility with existing systems are the key accomplishments of this design project. Issues and implementation details of each of these aspects are discussed and contrasted here. This paper concentrates on the processor performance issues associated with the package routing and power delivery. To overcome high inductance associated with the socket and package pins in the FCPGA package, decoupling capacitors were placed on the underside of the package substrate. This paper discusses an optimal placement scheme for the capacitors and their effectiveness in performance improvement of the system compared to the OLGA package case     

基于探测器阵列的激光远场光斑测量系统

设计开发了一套基于探测器阵列的激光远场光斑测量系统.在1.5 m×1.5 m的靶面尺寸上间隔10 cm排列了15行×15列激光探测器阵列,探测器响应信号经前置放大后分别进行同步脉冲产生和信号峰值保持、峰值信号A/D采样,最后经计算机通信存储,事后进行光斑图像的形成和分析处理.光斑能量密度测量范围10 μJ/cm~2～10 mJ/cm~2,单元探测器测量精度优于15%,最高测量激光频率可达500 Hz.可满足目前大功率激光干扰武器装备的测量需求.     

工业机器人坐标测量系统实时校准补偿技术

针对工业机器人测量系统连续长时间运行时参数不断发生变化,研究了一种采用实时校准的补偿方法.在测量周期内,多姿态测量空间固定点,根据固定点坐标与机器人参数的关系,快速反向求解出机器人变化的参数,实现机器人模型参数实时校准;将校准后的参数应用到测量模型中,有效地减小测量系统因机器人模型参数变化而引起的系统测量误差.实验表明...