IMEKO Event Proceedings

Page 852 of 866 Results 8511 - 8520 of 8655

W. Winiecki

The paper relates to the description of Virtual Instrument (VI). A new conceptual model of a virtual instrument is proposed. The model describes not only measuring devices, but also devices that can generate signals both analogue and digital. A compatibility between this model and a model of SCPI devices is shown. A new proposition for description of measurement equipment is also proposed. It makes more clear the classification of measurement equipment and enables one to differ a virtual instrument from a measuring system with a graphic user interface.

Jerzy Hoja, Grzegorz Lentka

The paper presents the method and the virtual instrument for monitoring of anticorrosion coatings performance. The developed method of component identification of the coating equivalent circuit is based on bilinear transformation. During the identification, the vector measurement of the object impedance is necessary at four selected frequencies. The analysis of optimal frequencies selection is presented assuring minimal identification error. The test results of implemented algorithm are shown. The results proved the possibility of shorten several times the testing time of anticorrosion coatings performance in relation to traditional impedance spectroscopy technique.

M. J. Korczynski, R. Gozdur
Virtual Instrumentation – a Key for Teaching Metrology and Quality Engineering

Teaching the practical aspects of engineering to potential engineers is a very important part of their education and it may also play a key role in their understanding of the engineering courses taught at universities. This paper describes how a virtual instrumentation based laboratory can be used to teach undergraduate students in "Metrology and Quality Engineering" at the Electrical and Electronic Engineering Department of the Technical University of Lodz. The low cost involved in building the laboratory was achieved by setting it up as a multifunctional flexible laboratory with shared resources. The individual work areas are connected via an INTRANET and can also be made available on the INTERNET, although there are some minor limitations while experiment are being performed at different remote locations. The experimental work areas each have PC based computer equipment which is grouped into three types of experimental benches: the first is equipped with a multifunction I/O or dedicated PCI cards, the second with desk top instrumentation and the third as a calibration work station. All student work areas, or benches, are supported by the full version of LabView® Ver. 6 software. These three groups form a kind of bank of instruments and are accessible from other computers, local or remote. The master stations, equipped with a MIO cards, are configured in such a way that the individual channels of the multifunction I/O cards can be assigned to individual PCs on the local net or distinct computers using a TCP/IP protocol. Sharing of a complete MIO PCI card is quite obvious, but access to individual channels on one PCI MIO card is a new idea and therefore had to be develop here at Lodz, exclusively for this application in our laboratory. The subjects supported by the virtual instrumentation are listed in the paper and the importance to quality engineering is highlighted and emphasised in the paper. The laboratory, as described, can facilitate distance learning in a practical way in many engineering subject areas.

Dan Mihai Stefanescu, Alexandru-Titus Farcasiu, Adrian Toader

The TensoDentar is a complex measurement system of dislodging forces for complete dentures or palatal plates. An original strain gauge force transducer (SGFT) and virtual instrumentation in NI and LabVIEW environment are used conforming to a rigorous clinical protocol to evaluate the efficiency of two surface treatments (sandblasting and plasma treatment) on complete denture base materials. The present work has the unprecedented goal to achieve in vivo comparison of the two techniques. First experimental results obtained are presented and interpreted.

Sergey Y. Yurish, Nikolay V. Kirianaki, Nestor O. Shpak

The universal solution for precise virtual instrument system realisation permitting to connect any frequency-time domain (quasi-digital) sensor to IBM PC compatible computers is described in the paper. The virtual instrument system for smart sensors with frequency-time domain output is based on the novel adaptive program-oriented method for frequency-to-code conversion – method of dependent count. The main advantages of this method for virtual sensor instrumentation applications are: high accuracy, constant quantization error in all frequency range, non-redundant conversion time, minimum possible hardware and self-adopting possibilities. The example of virtual instrument for duty-cycle output temperature sensor is given.

C.Bratescu, R.Burlacu, S. Ursache, R. Ciobanu

PDA-based instruments with wireless capabilities are a powerful aid to monitor and control applications. Using virtual instrumentation abilities of Labview 8.2, PDA, communications protocols and wireless devices we developed and tested some applications dedicated to the data transfer, workable for Pocket PC 2003. LabVIEW allow the addition of the dedicated module LabVIEW PDA Module, an essential resource in the development of graphical applications GUI usable on the PDA level

Florin Sandu, Iuliu Szekely, Wilibald Szabo, Gheorghe Scutaru
Virtual Instrumentation for Time-Domain Active and Reactive Power Measurement and Compensation in Industrial Networks

The authors implemented power measurement methods in non-sinusoidal regime using an original in-time signal processing: the temporal active power formula, applied to a pair of periodic signals representing voltage and current can be applied also to current (as it is) and Hilbert transform of voltage (kept in time domain) to compute the reactive power. The suggested algorithms were oriented towards digital signal acquisition and processing; their efficiency was compared with traditional methods and also with the implementation alternatives. Sampling rate was synchronized with the signal, as most industrial power meters don’t require a time reference (the power values are normalized to the period of the signal). The virtual instruments accomplished are directly applicable in real time monitoring and reactive power compensation for non-sinusoidal regime using recent developments in the technology of capacitors.

José Sánchez, Saúl Santillán, Sergio Padilla, Benjamín Valera, Rigoberto Nava, Gerardo Ruiz

Abstract - One purpose of Virtual Instrumentation in Metrology, is to empathise properties that put instrumentation away from idealisations. In actual instrumentation, geometric deviations trend to occur in relations 10-5, 10-7 of maximum displacements, requiring their representation in amplified way. If distortion of mechanisms is amplified hundreds times for its representation in CAD, many problems occur: linearity is lost between geometric relations; it is difficult to represent errors simultaneously for many axis and many degrees of freedom; operation of mechanisms doesn't satisfy cinematic of rigid body.
Since linearity is lost between linear and angular displacements, between articulate and operational spaces, and between real and amplified representation, it is necessary to apply functions and mapping procedures for relating them. Those mapping errors and their functions are important goals in the field of calibration, where virtual mechanical instrumentation may illuminate cases of controversy. The manuscript treats with several cases of distortion, their possibilities of amplification, their possibilities of assembling, and diagnostic trough inverse kinematics.

L. Swêdrowski

The best results of electrical motor’s diagnoses are obtained using the methods based on spectral analysis of vibration signals or on analysis of supplying currents (in the case of electrical driving systems). The most numerous group of driving system breakdowns is connected with the damages of roll bearings. In this case very effective diagnosing can be obtained using envelope signal processing (ESP) technique. The research stand elaborated in the Faculty of Electrical and Control Engineering (TUG) enables to make research with ESP diagnostic method used for rolling elements bearings as well as supplying current analysis. The diagnostic system is based on virtual instruments using LabVIEW of National Instruments The stand is equipped in numerous motors with determined defects as well as the motors of the same type being in good condition, computer, specialized software built on the base of LabVIEW package. The results of measurement, as panels of virtual instruments, created in LabVIEW, are shown in the paper.

L. Referowski, R. Roskosz, D. Swisulski
Virtual Instruments in the Program of the Electrical Measurements Chair (Tug)

The paper presents the experience of the team of the Technical University of Gdansk (TUG), Chair of the Electrical Measurements in using Virtual Instruments for educational purposes. These instruments can be used with great success for demonstration different physical phenomena during the lectures, especially to present different rapid effects in slow down time scale. They form marvellous help in understanding many theoretical problems. The virtual instruments can also be used in the virtual home laboratory, which enables students better preparation for real laboratory tasks. It is also possible to design specialised instruments for practical works in students laboratories and to substitute stand alone instruments which are sometimes inaccessible due to anxious financial situation of our faculty.

Page 852 of 866 Results 8511 - 8520 of 8655