基于虚拟仪器汽车发动机检测仪的开发

发动机综合性能检测仪器在汽车维修企业中的广泛使用势在必行。以计算机为主控单元,利用虚拟仪器软件开发平台LabVIEW8．5来设计发动机综合性能检测系统,系统具有中文操作界面,操作简单可靠、人机界面友好、功能完善、成本低、效率高等优点。     

基于USB和LabVIEW开发平台的虚拟仪器的设计

介绍一种虚拟仪器系统，该系统由支持USB2．0协议的板卡硬件系统和基于LabVIEW虚拟仪器设计平台的软件系统构成，可以完成信号采集，信号函数发生，信号处理以及波形显示等多种功能。     

基于虚拟仪器的声场可视化系统

基于虚拟仪器技术设计与实现了一种用于声场可视化的声信号采集与处理系统。该系统的功能包括声压信号采集和预处理,加载重建算法进行声场重建以及结果的可视化表示。系统硬件部分包括传声器阵列、数据采集卡和控制计算机。软件设计应用虚拟仪器的概念,并采用LabVIEW和MATLAB混合编程。通过实验测试,验证了该系统的实用性。     

基于VI的工程机械整机性能测试系统

该设计是为了对36路工程机械整机性能模拟(温度、压力、油耗、车速及轮边转速、发动机转速、扭矩、增压器转速、牵引力、液压流量、噪音、烟度、排放)信号进行采集和处理。该设计以动态数据采集模块PXI系列及前端调理适配设备SH系列为硬件平台,以流行的虚拟仪器(VI)软件Lab VIEW为运行平台,开发了拥有系统配置模块、参数配置模块、状态检测模块、标定系统模块、自校准模块、数据采集模块、数据处理模块七个模块组成的系统软件。最后通过应用证明了该系统的实用性、先进性、经济性和可靠性的特点。     

采用LabVIEW图形程式设计构成虚拟仪控设备

本文介绍了虚拟仪控的概念和LabVIEW图形程式语言的编程方法,性能特点,以及目前在广州地区的推广应用.     

A novel dual‐wideband inscribed hexagonal fractal slotted microstrip antenna for C‐ and X‐band applications

This paper presents a novel geometry of inscribed hexagonal slotted microstrip antenna for dual‐band performance where the fractal iteration has been made by introducing concentric slots in the patch geometry. Using the equivalence principle and cavity model, the basic geometry of the hexagonal slotted patch is analyzed, and the resonant frequencies of different modes of the patch are computed. Higher‐order modes of the patch antenna are used to obtain dual band. Good performance in terms of the reflection coefficient is proved with the help of parametric analysis. The antenna geometry is simulated using electromagnetic simulation software based on the finite‐element method. The prototype of this antenna is fabricated and tested. The practical results match with the simulated results. The proposed antenna provides improved average gain. The peak values of measured gain are found to be 5.238 and 7.023 dBi—in the two bands 5.85 to 6.48 GHz and 7.28 to 8.63 GHz, respectively. Stable radiation patterns with good average gain make the proposed antenna appropriate for long‐range transmission. Furthermore, low profile and low cost make this antenna suitable for the future point‐to‐point high‐speed wireless communication applications.     

Printed dipole antenna design using artificial neural network modeling for RFID application

An approach to printed dipole antenna design using the artificial neural network (ANN) modeling technique is presented in this article. Three important antenna‐layout dimensions are used to capture critical input/output relationships in the ANN model. Once fully developed, the ANN model has been shown to be as accurate as an EM simulator and much more efficient computationally in antenna design optimization. © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006.     

Millimeter‐wave planar high gain SIW antenna using half elliptic radiation slots

This article reports a high gain millimeter‐wave substrate integrated waveguide (SIW) antenna using low cost printed circuit board technology. The half elliptic slots which can provide small shunt admittance, low cross polarization level and low mutual coupling are etched on the board surface of SIW as radiation slots for large array application. Design procedure for analyzing the characteristics of proposed radiation slot, the beam‐forming structure and the array antenna are presented. As examples, an 8 × 8 and a 32 × 32 SIW slot array antennas are designed and verified by experiments. Good agreements between simulation and measured results are achieved, which shows the 8 × 8 SIW slot array antenna has a gain of 20.8 dBi at 42.5 GHz, the maximum sidelobe level of 42.5 GHz E‐plane and H‐plane radiation patterns are 22.3 dB and 22.1 dB, respectively. The 32 × 32 SIW slot array antenna has a maximum measured gain of 30.05 dBi at 42.5 GHz. At 42.3 GHz, the measured antenna has a gain of 29.6 dBi and a maximum sidelobe level of 19.89 dB and 15.0 dB for the E‐plane and H‐plane radiation patterns. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:709–718, 2015.     

时域天线阵的测试及其结果分析

将时域天线组成阵列是改善超宽带雷达技术性能一条行之有效的途径;研究时域天线阵辐射或接收的波形变换和畸变规律．是十分必要的;利用虚拟仪器技术,采用1．abView软件平台,使用模块化设计思想．实现一套慕于示波器和转台协调工作的时域天线阵自动测试系统的设计;通过对灭线阵测试结果进行分析,并与FDTD的仿真结果进行对比,得出关于时域天线阵有价值的结论。     

虚拟存储示波器的软硬件设计

本文在SJ8002B硬件平台基础上介绍虚拟示波器的设计原理和硬件组成,并使用Lab VIEW来实现虚拟示波器的软件设计。通过虚拟示波器的参数来介绍采集模块功能、波形显示以及最后对波形数据的储存,以方便对历史数据的调用和回显。     

基于虚拟仪器的计算机控制实验系统

本文介绍了计算机控制实验系统的开发及研究。在该系统硬件构成中,采用加热炉作为控制对象,试验仪器,线路板,数据采集卡及PC机,实现了对计算机控制技术的实践教学系统的硬件环境配置。实验系统软件采用虚拟仪器(VirtualIn-struments,VI)技术,开发环境是美国国家仪器公司(NationalInstruments,NI)推出的虚拟仪器应用软件开发平台LabVIEW7.0。系统投入使用后取得良好的教学效果。     

基于VI的动态应变测试系统设计

该设计是为了对100多路动态应变信号进行测试。在测试过程中以动态数据采集模块PXI系列及前端调理适配设备SH系列为硬件平台,以流行的虚拟仪器(VI)软件LabVIEW为运行平台,开发了拥有系统配置模块、参数配置模块、状态检测模块、标定系统模块、数据采集模块、校准系统模块、数据处理模块七个模块组成的系统软件。最后通过应用证明了该系统的实用性、先进性、经济性和可靠性的特点。     

High gain flexible liquid crystal polymer based 8‐element printed antenna for millimetric wave applications

In this article, an offset fed printed dipole antenna 2‐element, 4‐element, and 8‐element arrays are developed and analyzed for millimeter wave applications. The 8‐element array antenna is of compact size with dimensions 43.6 × 25.1 × 0.25 mm³. It achieved a broad impedance bandwidth (S₁₁ < ?10 dB) of 15.7 GHz from 24.7 to 40.4 GHz. The mutual coupling between array elements is less than ?35 dB in the operating band. The antenna achieved a gain of 12.62 to 13.1 dB. The 8‐element array antenna is fabricated on liquid crystal polymer material and tested. Impedance matching, far field radiation characteristics, co‐polarized and cross‐polarized patterns and group delay are analyzed in simulation and experimental measurement. The investigated results are in good agreement and hence, the developed array antenna is attractive for wideband millimeter wave applications.     

Design of micro‐machined modified Sierpinski gasket fractal antenna for satellite communications

Modified Sierpinski gasket fractal patch antenna for earth exploration satellite services has been proposed in this article. The proposed antenna is designed up to third iterative fractal geometry on the FR4 substrate having dielectric constant of 4.4 with height of 0.8 mm. The proposed design shows multiband characteristics at 2.8, 6.1, 7.96, 16, and 17 GHz frequencies. The maximum gain of the proposed design is 9.6 dBi has been achieved in Ku‐band. The resonating performance characteristics and radiation characteristics of the final iteration are investigated using simulator and experimentally to verify the results of the proposed design. The simulated and measured performance parameters show quite resemblance. Further, proposed design has been simulated on the micro‐machined high resistive silicon substrate which causes the improvement in gain and efficiency. Micro‐machined fractal antenna is compatible with monolithic microwave integrated circuits (MMICs).     

Near optimal conformal antenna array structure for direction‐of‐arrival estimation

This article determines the near optimal conformal antenna array structure for direction‐of‐arrival (DOA) estimation through a comprehensive study on the planar and usual conformal antenna arrays including the cylindrical and hemispherical by using the directive antenna elements in all designs. To model the hemispherical structure, an improved multi‐face antenna array with three different tilts is proposed and compared with previous works in order to investigate the tilt effect and obtain the conclusive results. The Cramer‐Rao lower bound, multiple signal classification, and root‐mean‐square error algorithms are utilized to evaluate the estimation accuracy of all conformal structures. Finally, by comparing the estimation precision of all conformal structures it is shown that the purposed multi‐face structure as the hemispherical model has a better performance than other conformal structures in terms of the maximum angular coverage of the spatial resource. Moreover, the proposed study method in this article fully examines the impacts of the different conformal antennas geometric structure on the DOA estimation performance by involving the directive antennas radiation patterns.     

基于虚拟仪器技术的轧辊磨床自动测控系统

在轧辊磨床的自动化改造中,根据精密磨床的机械特性和技术要求,结合虚拟仪器技术的独特优势,完成了对原有设备的自控改造。改造过程中使用了流行的图形化编程语言LabVIEW进行程序编写,结合DI、DO及AD采集卡,完成数据采集和系统控制。系统中主要利用了LabVIEW的串口通讯技术、复杂曲线方程的导入技术、代码接口节点技术以及动态连接库DLL的动态加载技术。实践证明,这样的方法对申小型钢铁厂完成陈旧磨床的自控改造过程是简单而有效的一种途径。     

Forecasting of Software Reliability Using Neighborhood Fuzzy Particle Swarm Optimization Based Novel Neural Network

This paper proposes an artificial neural network (ANN) based software reliability model trained by novel particle swarm optimization (PSO) algorithm for enhanced forecasting of the reliability of software. The proposed ANN is developed considering the fault generation phenomenon during software testing with the fault complexity of different levels. We demonstrate the proposed model considering three types of faults residing in the software. We propose a neighborhood based fuzzy PSO algorithm for competent learning of the proposed ANN using software failure data. Fitting and prediction performances of the neighborhood fuzzy PSO based proposed neural network model are compared with the standard PSO based proposed neural network model and existing ANN based software reliability models in the literature through three real software failure data sets. We also compare the performance of the proposed PSO algorithm with the standard PSO algorithm through learning of the proposed ANN. Statistical analysis shows that the neighborhood fuzzy PSO based proposed neural network model has comparatively better fitting and predictive ability than the standard PSO based proposed neural network model and other ANN based software reliability models. Faster release of software is achievable by applying the proposed PSO based neural network model during the testing period.      

CSRR based folded monopole tri‐band antenna array and its system level evaluation

In this article, a folded monopole antenna loaded with complementary split ring resonators (CSRRs) is proposed for tri‐band applications. The two bands of the antenna are generated by the folding of the monopole (first band is caused due to fundamental mode and another due to higher order mode) and CSRRs have been responsible for the third band. By using four such antennas in form of an array, the gain and bandwidth have been improved. The prototype of the antenna array is developed on FR4 substrate and simulated results are experimentally validated. A simplified equivalent circuit model of the antenna has been developed and analyzed to quantify the power loss due to input impedance mismatch at each resonance frequency. By using the EM model of the proposed antenna in the Keysight ADS verification test bench its suitability to operate in the system environment has been confirmed.     

Design of a linear array antenna for shaped beam using genetic algorithm

A linear array antenna design with desired radiation pattern has been presented based on genetic algorithm (GA) approach. Examples of cosecant and flat‐topped beam patterns are illustrated to show the flexibility of GA to solve complex antenna synthesis problems by suitably selecting the fitness function, even with a simple GA. The results have been validated by IE3D electromagnetic simulation. The antenna arrays with different element geometries can also be implemented using the proposed technique. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.     

A compact leaky‐wave antenna using a planar spoof surface plasmon polariton structure

This article presents and validates a leaky‐wave antenna by using the spoof surface plasmon polariton (SSPP) technique. By properly designing the proposed SSPP unit, the SSPP wave can be switched between the confinement and radiation modes. A large radiation efficiency can be achieved by properly designing the modulation depth, which ensures that a compact SSPP leaky‐wave array can be realized by using a small number of SSPP radiation units. To verify the design, a prototype which consists of a SSPP feeding network and a 4 by 4 SSPP radiation units has been fabricated by using a low cost FR‐4 substrate. A good agreement between simulated and measured results has been obtained. The proposed array antenna shows the promising capability of the SSPP technique for leaky‐wave antenna applications.