基于LabVIEW的电网综合参数测控系统设计

虚拟仪器软件LabVIEW已广泛用于测控系统的开发.介绍了在Labview中定制电网窗口风格的虚拟仪器技术,包括对菜单、工具栏和状态栏的定制和使用、数据库的使用等,对于设计功能繁多,控制复杂的虚拟仪器具有一定的指导意义.     

Multiple Virtual Interfaces for Multi-homing Hosts to Support Inter-technology Handover in PMIPv6 Network

Proxy Mobile IPv6 (PMIPv6), a network-based mobility management protocol, supports multi-homing, inter-technology handover, and flow mobility, with the help of a host’s virtual interface (VI). Several single virtual interface (SVI) schemes have been proposed to support these functions. In the SVI schemes, the link-layer identifier (LL-ID) should be swapped while the host is processing neighbor discovery (ND) after inter-technology handover or flow mobility. That is, a host must replace the LL-ID of a VI contained in a neighbor advertisement with the LL-ID of a physical interface (PI) related to a real connection. Such LL-ID swapping cannot be executed under secure neighbor discovery, and it causes ND processing delay and high overhead to check all outgoing packets. In this paper, we propose a multiple virtual interfaces scheme to solve the problem related to the LL-ID swapping, and to provide good support to the inter-technology handover. In the proposed scheme, there are the same numbers of VIs as the PIs between the data link layer and the network layer of a host. Since each VI maintains its own neighbor cache, the proposed scheme does not require LL-ID swapping, so that it can keep the standard ND process. We explain the basic operation of PMIPv6 inter-technology handover under the proposed scheme and, through NS-3 simulation, evaluate the performance of the proposed scheme in terms of ND process delay and inter-technology handover latency.     

基于声卡和LabVIEW的虚拟仪器设计与实现

为了在对采样频率要求不高的情况下进行信号的生成和分析,采用声卡取代价格昂贵的数据采集卡进行采样和输出,利用虚拟仪器开发软件LabVIEW,分别设计和实现了基于声卡的虚拟信号发生器和虚拟示波器。信号发生器可以产生方波、三角波等常用波形和自定义波形,示波器具有波形显示、图像暂停和截取以及频谱分析功能,所设计的虚拟仪器具有友好的人机界面,只需两台计算机即可进行完整的自测试     

基于LabVIEW的虚拟示波器的设计

虚拟仪器是电子测量技术与计算机技术深层次结合的、具有很好发展前景的新一类电子仪器。基于声卡的数据采集与分析的虚拟示波器,具有实现简单、界面友好、性能稳定可靠等优点。在LabVIEW环境中实现了与现实中实际示波器相似的功能。     

基于C8051F320单片机的低成本心电监护系统设计

介绍一种基于C8051单片机的动态心电监护系统。该系统由两部分组成：以C8051F320单片机为核心的数据采集装置和以PC机为平台的分析处理系统。硬件电路功耗低,由单片机自带的USB接口将数据传送给PC机。软件平台采用LabVIEW可视化虚拟仪器系统开发平台,将传统仪器的功能模块集成到计算机中,用户可通过修改虚拟仪器的程序改变其功能。采用USB接口实时传输心电数据,并将数据采集模块设计为计算机外设,使该系统高速快捷、小巧便携。     

An icon-based approach to system control development

The implementation of an icon-based manufacturing message specification (MMS) messaging system for system control in a manufacturing automation protocol (MAP environment) is described. The system was designed with a four-layer hierarchy. The top layer acts as a user interface and essentially provides a data manipulation service. The next layer invokes the appropriate firmware calls to manage the communication process. The third layer consists of the firmware that handles the actual transmission of data across the network. The lowest level is the actual network hardware. Twelve MMS services were implemented in order to provide the capability to carry out a typical control session. The system was tested using software that simulates the external communications of an MMS virtual manufacturing device. The LabVIEW MAP environment used imposed at least two limitations on the operation of the system. First, LabVIEW makes no provision for data structures; therefore, each parameter had to be passed from the MMS layer to the code VI layer as a variable of a specific data type. Second, LabVIEW provides no convenient way to maintain global variables throughout a diagram     

A tree‐based algorithm for virtual infrastructure allocation with joint virtual machine and network requirements

Cloud providers have introduced the on‐demand provisioning of virtual infrastructures (VIs) to deliver virtual networks of computing resources as a service. By combining network and computing virtualization, providers allow traffic isolation between hosted VIs. Taking advantage of this opportunity, tenants have deployed private VIs with application‐optimized network topologies to increase quality of experience of final users. One of the main open challenges in this scenario is the allocation of physical resources to host VIs in accordance with quality of service computing (eg, virtual CPUs and memory) and network requirements (guaranteed bandwidth and specific network topology). Moreover, a VI can be allocated anywhere atop a network datacenter, and because of its NP‐hard complexity, the search for optimal solutions has a limited applicability in cloud providers as requesting users seek an immediate response. The present work proposes an algorithm to accomplish the VI allocation by applying tree‐based heuristics to reduce the search space, performing a joint allocation of computing and network resources. So as to accomplish this goal, the mechanism includes a strategy to convert physical and virtual graphs to trees, which later are pruned by a grouped accounting algorithm. These innovations reduce the number of comparisons required to allocate a VI. Experimental results indicate that the proposed algorithm finds an allocation on feasible time for different cloud scenarios and VI topologies, while maintaining a high acceptance rate and a moderate physical infrastructure fragmentation.     

基于LabVIEW的电容加速度计测试软件设计

阐述了开放式虚拟仪器平台LabVIEW的特点;论述了电容式加速度计的数据采集原理;利用图形化编程语言LabVIEW的虚拟仪器和动态特性,在计算机上构成用户界面动态显示和交互,开发出了一个由计算机控制的数据采集系统,数据采集卡配合虚拟仪器中的LabVIEW编程,就能完成数据采集和计算分析的整个过程。实验证明采用这种方法省...     

用Labview开发SDH/PDH远程测试系统

本文应用National Instruments公司的LabVIEW6i图形化开发工具以及NI的TNT 4882CASIC PCI-GPIB接口卡成功开发HP37717B仪器驱动程序以及用户操作界面，利用可靠技术实现基于互联网技术的SDH/PDH远程测试系统。     

虚拟实验教学系统的研究与设计

传统仪器下的高校实验教学,已严重滞后于信息时代和工程实际的需要.运用虚拟仪器代替传统仪器,不但能满足电子信息类实验教学的需要,降低实验室成本,用户还可以根据自己需要定义仪器的新功能.本文主要设计了基于虚拟仪器的实验教学系统,采用模块化的设计思想,利用LabVIEW开发平台给出了低通滤波器实验、典型信号频谱分析实验、自相...     

云计算虚拟化技术研究

本文对云计算虚拟化技术的概念及其发展现状进行了阐述,并对虚拟化技术在云计算中的应用进行了具体分析。虚拟化技术包括虚拟整合、虚拟拆分和虚拟迁移。云计算使用虚拟整合技术将云平台中异构的物理资源整合成一个资源池,方便对资源的管理和分配;虚拟拆分将每台服务器拆分为多个虚拟机,通过虚拟桌面技术,每个用户能独占一个虚拟机,运行自己的应用,互不影响;虚拟迁移技术能够帮助云平台进行负载均衡和节约运行成本。最后对几种虚拟软件的性能进行了测试对比,分析了虚拟化带来的资源损耗问题。     

无线电车载监测站的信号采集与通讯系统

本系统采用LabVIEW对无线电监测信号进行采集和处理．并开发用户界面。在Delphi平台上运用远程访问服务实现了无线电车载监测站与中心固定站的通讯。LabVIEW主程序对通讯子程序进行调用。     

在LabVIEW平台上实现QPSK调制解调电路的虚拟

虚拟仪器概念的出现，是对传统仪器概念的重大突破，美国国家仪器公司（NI）开发的LabVIEW软件平台，是一个基于图形化编程的虚拟仪器软件平台，用它来开发各种仪器及虚拟电路具有独到之处，本文介绍了一种在LabVIEW平台上实现WPSK调制解调电路的虚拟方法。     

基于Labview和NI myRIO的智能避障小车设计

综合运用传感器监测、NI myRIO和LabVIEW技术,设计完成了基于LabVIEW和NI myRIO的具有智能和人工操控两种控制模式的智能避障小车。利用NI myRIO处理传感器采集障碍物的距离、小车移动的速度和小车前方是否存在障碍物等参数,通过板载的WiFi模块将数据传输给PC机,并由LabVIEW编写的用户界面实时动态显示和存储上述参数。测试结果表明,该系统高效灵活,具有较好的扩展性和兼容性,同时提供良好的用户操作界面,对智能车领域的发展具有重大意义。     

LabVIEW and PCI DAQ Card Based HTS Test and Control Platforms

This paper introduces the relevant parameters and related characteristics of the LabVIEW and PCI6221 data acquisition （DAQ） card, describes in detail the approach of building the measure and control platform of virtual instrument （VI） using LabVIEW and PCI6221, specifically discusses the system＇s application in high temperature superconductor （HTS） research including the test of HTS volt-ampere characteristics and the HTS magnetic energy storage. The experiments prove that the VI test and control system is easy to build and convenient to use.     

基于LabVIEW的电机虚拟实验平台设计

虚拟仪器是现代计算机技术和仪器技术相结合的产物,把虚拟仪器引入实验教学已成为一种必然趋势。本文在介绍虚拟仪器的概念、组成及软件开发平台的基础上,应用LabView作为开发软件,以电机虚拟实验设计为研究对象,设计了虚拟感应电机的机械特性曲线实验测定及其前面板,完成了实验曲线的测定。与实际测得的曲线进行对比,得出了较为满意的结果,这一设计为电机虚拟平台教学工作的开展提供了有益的参考。     

基于声卡的虚拟音频分析仪的设计

提出了一种基于LabVIEW和声卡的虚拟音频分析仪的设计方法，该方法实现简单、性价比高。生成的人机界面交互性好，操作方便，并且可以根据用户的需求进行功能扩充，为低成本下构建虚拟仪器提供了一种思路。     

基于虚拟仪器的模糊PID的设计研究

本文以LabVIEW为仿真平台,并利用其提供的PID和模糊逻辑工具箱,设计出一个模糊PID控制器。由于LabVIEW能快速构建实现交互控制系统的图形用户界,所以该控制器可以很容易的对3阶的线性被控对象快速进行模糊控制。实验结果表明,该控制器具有较强的抗干扰能力和鲁棒性,较好的动态特性。     

结合Flash和LabVIEW的“电子测量与仪器”教学

应用ActiveX技术将Flash制作的SWF文件调入LabVIEW程序中,再结合LabVIEW编写的虚拟仪器,在LabVIEW环境中实现了演示电子测量仪器原理和实验的多媒体教学。其中,Flash课件主要演示电子测量仪器的原理,虚拟仪器主要演示实验。结合FIash和Lab—VIEW,改善了演示窗口的整体效果。借助虚拟仪器技术在课堂现场演示实验,使理论教学及时结合实践教学,提高了教学效果。     

一种基于GPIB的自动测试系统实现方法研究

介绍了基于GPIB接口和LabVIEW软件平台组建自动测试系统的方法。所设计的测试系统通过GPIB接口总线实现PC机与通用测试仪器之间的通讯和对仪器的控制。探讨了测试系统的硬件构成、应用程序设计思路及具体的实现方法。该系统已在某型装备分机测试中取得很好的效果,提高了测试的自动化程度、测试效率和精度,易于扩展。