IMEKO Event Proceedings Search

   

Page 534 of 977 Results 5331 - 5340 of 9762

Erica Tena, Javier Castro, Antonio José Acosta
Automatic and Systematic Control of Experimental Data Measurements on ASICs

This paper presents a methodology to perform automatic and systematic characterization test on application specific integrated circuits (ASICs). The proposed methodology is based on the automatic control of all laboratory equipment and the data processing with Matlab. The ASIC, or integrated system, is connected to controllable test equipment to generate patterns and collect the output data provided by the ASIC. The methodology that provides the Matlab script controlling the equipment, test process, making the analysis of the results and supervising the whole process, can be easily adapted to different experiments and ASIC features. The test of a piecewise affine (PWA) ASIC controller has been used to experimentally prove the automatic control in both open-loop as well as in closed-loop configurations, reducing the risk of manual measurement errors.

Giada Giorgi, Andrea Veronese, Luca Corradini
A Method for Estimating State of Charge in Energy-Aware Wireless Sensor Nodes

The estimation of the Lithium-Ion battery State of Charge in a sensor node represents a challenging problem. The methods currently proposed in literature are mainly devoted to characterized the state of charge in portable electronic devices; however, their implementation in sensor nodes results to be unfeasible, both for the energy consumption and for the computational complexity. In this paper we will present a method for estimating the battery State of Charge, mainly based on a virtual implementation of the Coulomb Counting method, that aims to overcome some of the drawbacks of the existing methods and to fulfill the more stringent requirements presented by a sensor node.

Jan Hribik, Martin Boriš, Peter Fuchs
Average Value Evaluation of the Distorted Pulse Signal

Average value of the distorted pulse signal has been evaluated for two very often encountered distortions, namely finite rise and fall edges durations and oscillations (ringing) during the pulses. Relative errors of these average values are also given. The results can be applied e.g. in class D power amplifiers.

Gerardo Calva Olmos, Rafael Prieto Meléndez, Alberto Herrera Becerra, Alejandro Padrón Godínez, Mario Pacchiano de la Garza
Water Estimation in Sugar Cane Using Microwaves Signal

In this work are presented some details of the process in sugar cane to obtain sweet; the humidity is fundamental and currently the traditional laboratory test go on with each load in parallel to the process on cane; to conclude that the laboratory results in quality control for each load is known when the process arrive to the end of the chain, because of this there is not possibility to estimate the humidity level in the cane load at the moment when is entering the genius. The microwaves system would work in an alone frequency and would be taken advantage of the technique of signals reflection for in his operation. The microwaves system would be proposed as a complement to the already existing systems of quality control, those which already found in all genius.

Sakda Somkun, Thepbodin Borirak-Arawin
Quasi-analytical Design of a Square Helmholtz Coil with Finite Cross-sectional Area as a Magnetic Flux Density Standard

This paper describes a design methodology of a square Helmholtz coil with finite cross-sectional area to be used as a magnetic flux density standard up to 50 mT at NIMT. Magnetic field inside the square Helmholtz coil was considered to be assembled from the magnetic fields produced by every pair of square loops, which were analytically derived from the Biot-Savart law. This design technique, based on physical properties of the copper wires, allows the coil resistance to be easily predicted to match the output characteristics of the DC power supply. Temperature rise in the coil and the decrease of the coil constant due to thermal expansion were also taken into account. The calculated magnetic field was found to be closely agreed with finite element modelling (FEM). A design prototype was constructed and results showed good agreements with the numerical calculation.

Zivko Kokolanski, Cvetan Gavrovski, Vladimir Dimcev
Improving the Single Point Calibration Technique in Direct Sensor-to-Microcontroller Interface

An improved single point calibration technique applied on direct sensor-to-microcontroller interface is presented. The improvements are in reducing the systematic errors in a given measurement range by increasing the transfer characteristics nonlinearity. The experimental results showed that this approach reduces the overall systematic errors of the measurements more than twice and considerably increases the measurement speed. In the paper, theoretical and experimental analyses are performed for resistive modulating sensors.

Diego Silva, Roberto Sato, Agostinho Castro
A Portable and Low Cost Solution for EMG using ZigBee,GPRS and Internet to Biomedical applications

This paper presents a prototype of an acquisition board of electromyographic signals (EMG); an embedded portable, wireless and low cost solution. The system is composed of an EMG acquisition board, Zigbee modules and a device named GPRSx. After acquiring the EMG signal, it is sent through ZigBee wireless technology to GPRSx device. The GPRSx device sends the EMG signal to a server on the Internet by using GPRS wireless technology. Thus, the EMG signal is displayed in a graph on a remote computer. The results are very promising and may serve as a reference in studies for the biomedical area.

Malone Soares de Castro, Raimundo C. S. Freire, Edson Guedes da Costa, Euler C. T. Macedo, Newton S. S. da Fonseca, Thais L. Silva
Experimental Evaluation of Potential Distribution in a Grounding Grid Subjected to Impulse Current

A methodology to evaluate the response of a grounding grid system subjected to electrical current impulses is proposed in this work. The methodology is based on analysing the signal of voltage propagated in the vicinity of the injection rod. An impulse generator (80 kJ/100 kV) was used to generate waveform 8/20 µs, this is a signal that represent lightning surge. The signals were acquired using by a digital oscilloscope. From the results obtained, one observes that the amplitude of propagated voltage is attenuated in the direction of propagation.

Rafael Moura Duarte, Juan Moises Mauricio Villanueva, Maxwell Moura Costa, Raimundo Freire, Sebastian Yuri Cavalcanti Catunda, Wendell Moura Costa
Ultrasonic Time of Flight Estimation for Wind Speed Measurement Based on Time-Frequency Domain Using STFT

This paper presents a procedure for wind speed measurement using ultrasonic transducers based on short-time Fourier transform (STFT). The measurement of wind speed was performed by estimating the ultrasonic transit-time (ToF). For this purpose the estimated ToF was used the technique of digital signal processing, based on the STFT. The ultrasonic signal detection was performed by setting a threshold level equivalently half the maximum power for the operating frequency of the ultrasonic transducers. Simulation results are presented considering the influence of the additive noise Gaussian, and estimation of ToF considering the evaluation of STFT windows using Hamming, Hanning and Bartlett.

Krzysztof Musiol, Tadeusz Skubis
Extending the scale of inductance using 1:1 comparator bridge

An idea of using 1:1 comparison for 10:1 and 1:10 impedance transfer is described in the paper. Results of measurements performed for 10:1 transfer of inductance are discussed. The results achieved prove that using 1:1 comparator bridge and applying proposed procedure is possible to transfer unit to the objects of 10 times smaller values with relative uncertainty only a little higher than uncertainty estimated for 1:1 comparison.

Page 534 of 977 Results 5331 - 5340 of 9762