A Direct MRJ Hankel Transform System Using Rotating Gradients

A novel magnetic resonance imaging system is explored which uses data collected in the presence of quadrature phase sinusoidal gradients along an excited plane. It is shown that the resulting magnetization signal (FID) is a sum of the Hankel transforms of the radial modulators of the imaged plane. An efficient processing system is suggested which extracts the different Hankel transforms from the received signal. These transforms are used to directly reconstruct the two-dimensional (2-D) image using either 1-D inverse Hankel transforms or a 2-D inverse Fourier transform. A "snapshot" data acquisition procedure is described which enables the collection of all the required data from a signal FID. The main advantages of the proposed system are rapid acquisition time, the ability to trade-off acquisition time, and SNR and resonant gradient circuits.     

用于焦平面测试系统的高效高精度数据采集方法与实现

通过分析焦平面测试中各种性能参数对数据要求的特点,提出了一种区别于传统的高效数据采集方法,并采用ADI最新发布的16位高性能ADC,设计了基于该方法的高效高精度采集系统.通过内嵌的“RMS硬件算法”和外部SRAM的特殊组合,在兼容传统测试系统的同时,大大提高了系统的测试效率.经碲镉汞(HgCdTe)型640×512(1...     

红外计算机采集系统及其应用

在由通用红外探头、通用采集卡和计算机组成的硬件平台上,用C#.NET作为软件开发工具研制了一套红外信号采集系统。利用计算机对终端红外探头数据进行了快速采集和高速分析处理.本文主要介绍了设计的主要思路,包括系统功能、硬件结构、编程思路等。     

Suppression of slice selection axis motion artifacts in MRI

Patient motion during data acquisition in magnetic resonance imaging causes artifacts in the reconstructed image, which for two-dimensional Fourier transform imaging techniques appear as blurring and ghost repetitions of the moving structures. T. Mitsa et al. (1990) proposed a technique for suppressing artifacts from periodic motion along the slice selection axis. A different approach to the same problem is presented which is not restricted to periodic motion. The algorithm is verified using a simulated phantom and motion. It is also shown to perform well in the presence of noise and motion within the imaging plane.     

Design of vision measurement system of double optical paths with single CCD based on DSP

The design of vision measurement system of double optical paths with single CCD based on the digital signal processor （DSP） is presented. Using TMS320F2812 as the intelligent control unit, the CCD driving circuit, level conversion circuit and CCD output signal data acquisition and processing circuit are designed. By means of plane reflectors, the optical structure of the system is optimized, which reduces errors owing to tilt effect of the measured unit, improves measuring accuracy and makes the system more compact. Double optical paths signal data acquisition with single CCD is demonstrated. In addition, the improved resolution is enhanced up to sub-pixel level by the average polynomial interpolation algorithm.     

工业机器人的局部标定

以ABB公司的IRB120工业机器人和激光位移传感器组成的数据采集系统为研究对象,通过对实验系统底座平面上数据点的采集和处理,来标定机器人与激光位移传感器之间的齐次变化矩阵。以采集到的数据点在机器人坐标系中位于同一个平面上为标定原理,利用最小二乘法拟合平面方程,得到机器人需要标定的各个参数及平面参数。在最小二乘优化处理过程中,通过对不同优化结果的分析对比,最终得到最优解,并为以后该系统在数据采集中的应用提供依据。     

高精度多路数据采集系统的设计

随着信息技术的发展,现代的电子测控系统对数据采集器提出了更高的要求。介绍一种基于串行A／D的数据采集系统的设计方案,结合TI公司的10位串行A／D芯片TLC1549,通过提升它的测量分辨率,使之达到12位的精度;用电子开关扩展其输入通道,实现了八路信号的数据采集,进而设计出了高精度、高分辨率、多通道的数据采集系统,并给出了硬件接口电路设计以及软件系统流程设计。     

基于MAX 7000A与CYUSB3014的USB3.0数据采集系统的设计

文章设计与开发了一套USB3.0数据采集与传输系统,该系统采用MAX 7000A为主控芯片,CYUSB3014为USB3.0接口芯片。本文先给出硬件系统的设计,然后介绍了固件和驱动程序的开发。经测试,该系统能实现超高速数据采集与传输。     

基于带通采样的高速数据采集系统设计

高速数据采集系统是现代雷达信号处理不可缺少的重要组成部分。文章以宽带侦察接收机信号处理为应用背景,论述了一种基于带通采样的高速数据采集系统的设计方案。该方案以Xilinx公司Virtex-5系列FPGA为平台,控制高速模数转换器ADC08D1000,完成数据采样、传输、存储、信号处理功能,并选取高速FIFO作为存储设备,解决数据率转换问题。该系统实现了软件、硬件设计,测试结果验证了方案的可行性。     

Grating lobe reduction in ultrasonic synthetic focusing

Two novel schemes of data acquisition in synthetic aperture ultrasonic imaging systems using a linear array transducer are presented to solve the troublesome grating lobe problem. Simulation and experimental results show that in both schemes the grating lobes are significantly reduced without appreciable degradation of the main lobe characteristics.<>     

基于双串口和多进程的实时数据采集方法研究

结合飞机静压自动测量系统的研制,提出了一种利用双串行通信接口和多进程技术在运动状态下实时采集测量数据的方法,即采用双串口来实现测量数据的实时采集。利用ActiveX EXE部件开发状态监测进程,用异步事件的方式通知主进程采集数据。应用结果证明,该通信方法有效可靠,满足了系统的实时性要求。     

基于RS 485总线的数据采集处理系统

为了解决多通道数据的远程采集和处理问题,介绍基于RS 485总线的串行通信数据采集处理系统的方案设计。给出RS 485通信接口的具体硬件电路,应用VC 6.0编写PC机软件,完成了PC机与数据采集模块的串行通信及数据处理的软件系统设计,实现了对多通道现场数据的实时采集和处理,系统具有较强的实用性和扩展性。     

Modeling of data acquisition systems using the queueing theory

This paper describes the features of a data acquisition system modeling based on queueing theory method. The main elements of the studied data acquisition system structure are sample hold amplifiers and dual-slope analogue digital converters. In case of the threshold control of technological facilities parameters, alarm signals in the system input are presented as a flow of customers with the Poisson intensity distribution. A converting time of these alarms in analogue digital converters depends on signal levels and is described by an exponential distribution. In this case we present the data acquisition system as the Markov model of the multichannel queueing system with a limited queue. This modeling method may help the data acquisition system structure to adapt to characteristics of input signals and features of communication lines in an output of system.     

便携式红外靶标发生器的研制

介绍了一种适用于工作现状及技术阵地快速检测热成像装置ＭＲＴＤ的便携式红外装置,它由红外光学系统,靶标,面源黑体,温控装置及显示装置组成。靶标和面源黑体组成的温差源通过红外光学系统成像到远限远,模拟无限远目标,供给热成像装置接收。光学系统采用摄远物镜结构实现便携要求,靶标及面源黑体的温度采用温控仪探测,由Ｚ８０单片机进行对温控仪的数据采集处理和显示,并通过一定方法的温控过程保证靶标与面源黑体之间温差     

基于MSP430多功能无线监测系统的设计

针对传统监测系统存在局限性问题,设计了基于无线数据收发芯片nRF905、以MSP430F149为主处理芯片的多功能无线监测系统,给出了无线监测系统框图和部分软硬件设计,在供能、采集精度、抗干扰性、传输距离等方面做出了探索工作。实验表明本系统运行速度快、传输距离远、精度高、功耗低。无线监测系统相比有线监测系统应用灵活,可移动性强,将是未来监测系统发展的主要方向。     

机载武器制导系统研究

时机载制导武器进行了阐述,介绍了机载制导武器的系统,论述了机载武器制导系统的使用特点及局限性,并对其主要技术性能和关键技术进行了分析.     

微型光谱仪的CCD 数据采集系统设计

微型光谱仪是近年来光谱仪发展的主要方向。针对微型光谱仪数据采集系统的设计需求,应用TCD1304DG 线阵CCD 完成了以FPGA(EP4CE15)为控制核心的高分辨率数据采集系统设计,系统使用了集成Programmable Gain Amplifier(PGA)、16 位模数转换功能的Analog Front End(AFE)芯片,开发了USB2.0 高速数据传输电路并完成了光谱采集上位机软件的设计,实现了对光谱数据的实时处理。小型集成的电路设计方案满足了光谱仪对小型化、便携使用的特点和要求。     

广播发射机分布式计算机数据采集与控制系统

针对广播发射台的强电磁环境,从工程角度出发,提出了由PC机和STDS000系列工控机组成的分布式计算机测控系统,实现了对多台广播发射机的数据采集,监测控制,故障报警及运行管理。着重讨论了系统的结构组成,软件功能及运行模式,并引入了windows环境,BITBUS通信网。     

基于IP over SDH河南电力调度数据网规划及互联

根据调度数据网承载信息的特点及网络安全的需要,介绍了基于IP Over SDH的河南电力调度数据网络的总体规划和调度数据网双平面、河南省电力调度通信中心接入网的网络规划和结构。对基于河南电力通信网ECI第一平面和华为(HUAWEI)第二平面的调度数据网设计要点和网络保护机制进行了理论分析。对河南电力调度数据网建设过程中骨干网协议互联以及接入网2M对接中协议设置进行了说明,为保障调度数据网的安全运行和故障分析提供了有力的依据。     

MCYT baseline corpus: a bimodal biometric database

The current need for large multimodal databases to evaluate automatic biometric recognition systems has motivated the development of the MCYT bimodal database. The main purpose has been to consider a large scale population, with statistical significance, in a real multimodal procedure, and including several sources of variability that can be found in real environments. The acquisition process, contents and availability of the single-session baseline corpus are fully described. Some experiments showing consistency of data through the different acquisition sites and assessing data quality are also presented.