Cristina Temneanu, Marinel Temneanu
Most existing control schemes developed with fuzzy logic are using extensive memory and processing power. Motivated by the need for computationally efficient controllers, the structure with two uniformly distributed membership functions is considered. The control algorithm is designed with minimal fuzzification features in case of a linear dynamic process control. The goal of this work is to emphasize the influences of ADC and DAC converters used at the interface level with the real process onto the overall controller performances. The study is made using computer simulation in LabView...
TC4 Workshop 2005
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T. Alexandropoulos, S. Boutas, V. Loumos, E. Kayafas
This paper presents a template-based inspection application for change detection. This implementation aims to the inspection of targets which appear at an arbitrary orientation, such as undervehicle surfaces in vehicle inspection stations. The operation of the application is divided in two phases: image registration and change detection. Image registration aims to accurately detect the spatial transformation parameters which describe the orientation of the target with respect to its template. Change detection separates content changes from sensor noise fluctuations through noise model...
TC4 Workshop 2005
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Cristian Fosalau, Marinel Temneanu, Cristian Zet, Emil Vremeră
The paper presents a new current sensor whose operation principle is based on the Giant Magnetoimpedance Effect (GME) occurring in non-magnetostrictive magnetic amorphous wires (MAW). This effect consists in sudden variations of the voltage drop picked-up from the ends of an amorphous wire when a high frequency current flows through it and it is subjected to an external axial magnetic field. The wire is mounted around a cylindrical conductor, through which the measured current flows, thus creating the necessary axial field to which the sensor is sensitive. Construction, operation principle...
TC4 Workshop 2005
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Marinel Temneanu, Cristian Fosalau and Cristina Temneanu
An electric equivalent circuit for Co-based amorphous wires is studied in this paper. Its structure is based on some simple assumptions related to domain structure and the coupling between these domains but also on the presence of the specific relaxation mechanisms. Model parameters were identified using impedance spectroscopy techniques.
TC4 Workshop 2005
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M. Music, M. Ahic - Djokic
Passing through the vortex street, behind the bluff body, amplitude and phase modulation of ultrasonic wave happen at the same time. Level and form of modulating signal depend of mean flow velocity and shape and size of vortices. In this paper, one combined method of signal processing, converted ultrasonic to electronic signal, using amplitude or phase demodulation, has been presented. Choice of processing depends on the mean flow velocity. Also, experimental results, using prototype ultrasonic vortex flowmeter PVMP50, based on noticed method have been presented.
TC4 Workshop 2005
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Damir Ilić, Josip Butorac, Luka Ferković
The table data for R-T dependence of NTC resistors (NTCRs), which have resistance RN = 10000 Ω at a temperature of 25 °C and limits of error ±0,2 °C in the range (0 to 70) °C [1-4], are analysed. The determination of two approximation curves is described: a three-parameters (abbreviated as AC1) and a two-parameters (AC2). These curves are compared with the three-parameters Steinhart-Hart equation (S&H) by using the table data of resistance for different NTCRs and calculating the following for all of them: unknown parameters by the least-squares method, approximated temperature using...
TC4 Workshop 2005
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Przemysław Otomański
Results of experiments concerning humidity measurements have been presented in the paper. Integrated humidity sensors were used for the experiments, which transformed the value measured into a corresponding capacity. The structure of a measuring system was described, and the requirements concerning particular elements of the measuring track were defined. Using the regression method, an analytical equation was modelled, combining the output capacity value of the sensor with the examined humidity changes. With the use of the experimental results as well as the least square method, the values...
TC4 Workshop 2005
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F. Adamo, G. Andria, F. Attivissimo, L. Fabbiano, N. Giaquinto
The work proposes an accurate, on-site and real-time method to measure the moisture content of agricultural soils; the idea is to estimate the moisture measuring the velocity of propagation of seismic waves in the medium applying a new model based on the use of both compressional and shear waves. In a previous paper the authors derived the relationship between the compressional wave speed and the moisture content for various kind of soils; they also derived the conditions for the actual validity of the proposed relationships and a suitable range of frequencies for the sound used as the input...
TC4 Workshop 2005
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Ricardo Queirós, Pedro Silva Girão, António Cruz Serra
The impedance characteristics of piezoelectric ultrasonic transducers can be described with the help of an electrical equivalent circuit. The circuit permits transducer analysis. Therefore, it is desirable to have a way of determining the equivalent circuit parameters of a given transducer. We propose a method which can basically be divided in two parts: 1) Approximate calculation of the circuit parameters and 2) Increase the accuracy of the parameters by optimization techniques. For its availability and relatively simple implementation, the optimization toolbox of MATLAB was used to perform...
TC4 Workshop 2005
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A. Cataldo, L. Tarricone, F. Attivissimo, A. Trotta
Time-domain Reflectometry (TDR) is a well-established technique for the development of microwave sensors devoted to the dielectric characterization of materials. This renders TDR an appealing method for a variety of monitoring applications. Till now, TDR has been successfully applied to solve hydrological or soil prospecting problems, though its adoption in many other cases is worth an investigation. In this paper, it is demonstrated that TDR is a viable approach for quantitative and qualitaive real-time characterization of liquids inside tanks. In fact, in one shot the suitable handling of...
TC4 Workshop 2005
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