Graphical Language LabVIEW Research Articles

FULLY TIME-DOMAIN SCANNING OF EM NEAR-FIELD RADIATED BY RF CIRCUITS

This paper deals with planar scanning technique of electromagnetic (EM) near-fleld (NF) emitted by electronic printed circuit boards (PCBs) fully in the time-domain (TD). The proposed EM scanning metrology is essentially based on the NF test bench available at the IRSEEM laboratory. It comprises motorized mechanical structures for moving the probe interconnected to electronic measurement instruments and controlled by a driver PC. The synoptic of the test bench is presented and technically examined. The characteristics of difierent elements constituting the measurement chain of the TD test bench understudy are described. The NF metrology developed is originally focused on the measurement of time-dependent magnetic fleld H(t) dedicated to the radiated emission electromagnetic compatibility (EMC) applications. An innovative calibration technique of the loop probe for detecting H(t) is established in order to ensure the post processing and extraction of the measured NF data. Then, validations were carried out via comparison with difierent simulations run with standard commercial tools. Mathematical analyses were also conducted for the improvement of the measurement post processing. To realize the mapping of time-dependent EM fleld components, a software interface edited with the graphical language LabVIEW was emulated to synchronize the probe displacement and the data acquisition. An UWB amplifler with average gain about 30dB from DC to 300MHz was designed and fabricated in order to decrease the measurement noise and to improve the quality of measured signals. As results of the study, TD NF mapping is demonstrated successfully by measuring the EM radiation emitted by electronic planar circuits. The technique developed is extremely useful in the fleld of EMC engineering for predicting the transient perturbations susceptible to degrade electronic functions in complex systems encountered usually for the automotive and aeronautic applications.

Lifting Capacity Detection System of Tower Crane Based on LabVIEW

The real-time acquisition of lifting capacity is a common problem in the course of tower crane work. Its an accurate and reliable method to use shaft pin type load cell to convert weight to electrical signal which is detected and processed in practical. Using STC89C52 as the core processor, the hardware consists of signal section modulating circuit, acquisition circuit and communication circuit; C language and LabVIEW graphical language are used to develop the system, including A/D conversion, data transmission, reduction and linear compensation, section control and data storage. As shown in the experimental results, the system improves the detection accuracy of the lifting capacity. It has friendly man-machine interface and is easy to analyse and process subsequently.

Design of Instrument Control System Based on LabVIEW

In order to solve the problems such as poor expansion, long development cycle of instrument control system developed by traditional programming language, using VISA module based on LabVIEW platform was introduced. This paper presented a simplicity, intuitive instrument control system of pneumatic measuring instrument, which was accomplished with graphical language LabVIEW. The system could also complete the text data output. It was improved that the system based on LabVIEW achieved instrument control efficiently, openly, with operating conveniently and good human-machine interface. DOI: http://dx.doi.org/10.11591/telkomnika.v11i6.2719

A LabVIEW Platform for Preclinical Imaging Using Digital Subtraction Angiography and Micro-CT

CT and digital subtraction angiography (DSA) are ubiquitous in the clinic. Their preclinical equivalents are valuable imaging methods for studying disease models and treatment. We have developed a dual source/detector X-ray imaging system that we have used for both micro-CT and DSA studies in rodents. The control of such a complex imaging system requires substantial software development for which we use the graphical language LabVIEW (National Instruments, Austin, TX, USA). This paper focuses on a LabVIEW platform that we have developed to enable anatomical and functional imaging with micro-CT and DSA. Our LabVIEW applications integrate and control all the elements of our system including a dual source/detector X-ray system, a mechanical ventilator, a physiological monitor, and a power microinjector for the vascular delivery of X-ray contrast agents. Various applications allow cardiac- and respiratory-gated acquisitions for both DSA and micro-CT studies. Our results illustrate the application of DSA for cardiopulmonary studies and vascular imaging of the liver and coronary arteries. We also show how DSA can be used for functional imaging of the kidney. Finally, the power of 4D micro-CT imaging using both prospective and retrospective gating is shown for cardiac imaging.

유량제어용 서보밸브와 비례방향밸브의 압력신호를 이용한 정적 성능 진단에 관한 연구

Most diagnosis methods for servo valves requires installing spool displacement sensor or flow sensor as well as pressure sensor. The measurement of flow is hard to implement and many kinds of servovalves or proportional direction valves do not have a built-in spool displacement sensor. In this study, static performances of servovalve or proportional-direction-valve are studied theoretically and a diagnosis technique, which uses only load pressure and input current signal, is assessed. An experimental setup was made based upon a personal computer and the LabVIEW graphical language. A series of diagnosis tests were performed and the analysis results showed it possible to measure the pressure gain, hysteresis and null bias in a relatively simple methodology.

Design of Measurement and Control System for Medium and High Pressure Hydraulic Pump Test Platform Based on PXI Bus Structure

Based of PXI (PCI Extensions for Instrumentation) bus structure, a measurement and control system for medium and high pressure hydraulic pump test platform is designed in this paper. This system is comprehensive testing equipment which has adopted the traditional technologies include hydraulic, computer, virtual instrument and detecting. Its measurement and control system has introduced new techniques with combining PXI bus structure and relay, which can realize manual/automatic synchronical operation and one key operation. Use graphic language Lab VIEW 9.0 as its developing platform, the system realizes synchronically display of the mechanical instrument and the virtual instrument which has increased the test accuracy and speed.

Study on Data Acquisition for Heavy Off-Road Vehicle AT Testing

Based on the analysis of the testing automatic transmission (AT), the AT’s solenoid valve control signals conditioning circuits and revolving speed F/V converter conditioning circuits are designed, and the data acquisition system is designed based on virtual instrument. The system is composed of the PCI-6024E data acquisition card, signal conditioning circuits and computer, and the acquisition procedure is programmed in graphical language LabVIEW. Finally, the data acquisition system has been verified on vehicle test bench which loads ZF-Ecomat 6HP500 AT. Controlling signals of switching solenoid valves, duty cycle signal of proportional solenoid valve, accelerator aperture signal, oil pressure signals and speed signals are collected, it turns out that the data acquisition system has good feasibility.

Using LabVIEW ™ for advanced nonlinear optoelectronic device simulations in high-speed optical communications

We present an advanced and comprehensive semiconductor optical amplifier model to analyze the propagation and amplification of 10 to, in principle, 1280 Gb/s ultra-short optical pulse sequences. Through appropriate transformation, the partial differential propagation-rate equation problem is numerically solved in a two-dimensional grid of fine resolution. The corresponding simulator, entirely programmed in the graphical language LabVIEW, is compared to an identical simulator implemented in the popular high-level text-based language Matlab. Special care has been taken to implement the same set of algorithms using equivalent codes for each language, such that a fair and objective one-to-one comparison can be carried out. In terms of computational time the LabVIEW simulator shows a tenfold outperformance, compared to its text-based identical counterpart implemented in Matlab, when typical bit sequences at 40 Gb/s with a length of 8 to 1024 bits are tested. The performance results presented here apply to a broader set of device modeling scenarios.

Hardware and software design for an electromagnetic induction tomography (EMT) system for high contrast metal process applications

This paper presents the latest development of an EMT system designed for use in the metal production industry such as imaging molten steel flow profiles during continuous casting. The system that has been developed is based on a commercial data acquisition board residing in a PC host computer and programmed in the LabView graphical language. The paper reviews the new EMT hardware electronics and software. The noise effects and the detectability limits of the system are given in the paper followed by the system sensitivity map analysis. Optimal image reconstructions, including the simultaneous iterative reconstruction technique (SIRT) and non-iterative Tikhonov regularization, truncated singular value decomposition (TSVD), are also discussed and applied for the system. The system has been demonstrated in real time (10 frames s−1 for 5 kHz excitation) with test phantoms that represent typical metal flow profiles such as central, annular stream and multiple streams.

Analytical aspects of silica in saline water — application to desalination of brackish waters

In several areas like water desalination and geothermal applications, the occurrence of silica in the used waters is undesirable. Many studies show the complexity and the diversity of the topic. For a better understanding of some of its analytical aspects the determination of amorphous silica content of natural waters, was carried out by various analytical methods. Amorphous silica solubility, at different temperatures, pH and ionic strength was studied. The heat of silica dissolution and the activity coefficient of dissolved silica were determined. A microcomputer program with the LabView graphical language was designed to calculate the solubility and concentration factors that indicate the limits above which silica precipitation occurs. This practical tool was applied to a variety of aqueous salt solutions and to some brackish waters from South Tunisia, at different temperatures. Predicted solubility values, using deduced silica activity coefficient, are in good agreement with experimental results.

Thermodynamic description of saline waters — Prediction of scaling limits in desalination processes

A thermodynamic modeling of saline waters is achieved taking into account acid-base, ion associates formation and precipitation equilibrium. A microcomputer program, written in the graphical language LabView accomplished the necessities of iteration for the solution of simultaneous equations, calculations. Extended Debye-Hückel and Pitzer models were used for the activity coefficient calculations. The program allows determining the repartition of free ions, ion pairs, and weak acid species. Calcium carbonate stability of water was predicted thanks to calcocarbonic equilibrium curves calculation. Concentration factors for calcium carbonates, calcium sulfates and silica were also calculated. The calculations were carried out for different kinds of saline waters at different temperatures. For representative calculations, standard seawater and brackish feed water for a reverse osmosis desalting plant in Gabès region (in South Tunisia) were selected.

Graphical programming for pulse automated NMR experiments

We describe a software program designed to control a broadband pulse nuclear magnetic resonance (NMR) spectrometer used in zero-field NMR studies of magnetic metals. The software is written in the graphical language Labview. This type of programming allows modifications and the inclusion of new routines to be carried out easily by the non-specialist, without changing the basic structure of the program. The program corrects for differences in the gain of the two acquisition channels (U (phase) and V (quadrature)), and automatic baseline subtraction. We present examples of measurements of NMR spectra, spin-echo decay , and quadrupolar oscillations, performed in magnetic intermetallic compounds.