Search

Search Results

• Analysis of an Induction Machine by the Finite Element Method

  1-5.

  Miklós Kuczmann

  Krisztián Gadó

  Sándor Horváth

  István Vajda

  Dániel Marcsa

  Anouar Belahcen

  Views:

  203

  Induction machines are popular in every segments of industry due to their simple construction and robust operation. Asynchronous machines have been being built in electric vehicles, too. The paper presents the two dimensional analysis of a voltage-fed induction machine by different kind of finite element software. The results have been compared.

• Development of Gait Recognition in NI LabVIEW

  1-3.

  Dániel Salánki

  Kornél Sarvajcz

  Views:

  93

  Nowadays, one of the most significantly improving area in security is the world of biometric identifiers. Within the biometric identifiers, the research group is working with the gait recognition speciality. The research group realized a complex gait recognition system in NI LabVIEW, that can detect more reference points simultaneously with a universal camera and is capable of suiting predetermined curves on the detected points. Moreover, the program can compare the functions suited on the reference curve and the actual curve and evaluate if the two gait images are the same or not. In the program there is a saving and a reloading function which cont ributes to the production of the reference gait image. The foot analysis program before the gait recognition is designed to improve accuracy. The self-developed gait recognition system was tested on more persons and the False Acceptance Rate (FAR) was zero.

• Application of OptiTrack Motion Capture Systems in Human Movement Analysis: A systematic Literature Review

  1-9.

  Gergely Nagymáté

  Rita M. Kiss

  Views:

  3687

  With the spreading of motion analysis decisions to invest into a new system demand scientific reference applications. The aim of the present systematic review is to reveal the biomechanical scientific applications of OptiTrack motion capture systems and to overview documented usage conditions and purposes. Six major scientific literature databases were used (PubMed, PubMed Central, ScienceDirect, IEEE Xplore, PLOS and Web Of Science). An OptiTrack camera system had to be used for human or biologically related motion capture. A total of 85 articles were included, 4 out of which dealt with the validation
  of OptiTrack systems and 81 utilized the system for biomechanical analyses. The data analysed and extracted from the system validation studies included: description of the validated and the reference system, measured features and observed errors. The data extracted from the utilizing studies also included: OptiTrack application, camera type and frequency, marker size, camera number, data processing software and the motion studied. The review offers a broad collection of biomechanical applications of OptiTrack motion capture systems as scientific references for certain motion studies. The review also summarizes findings on the accuracy of the systems. It concludes that the method descriptions of system usage are often underspecified.

• Sizing and Economic Analysis of Standalone PEM Fuel Cell Systems for Residential Utilization

  1-8.

  Sherif M. Imam

  Ahmed M. Azmy

  Views:

  61

  This study discusses the economic utilization of proton exchange membrane fuel cell (PEMFC) based on cost of energy (COE) to supply residential electrical and thermal loads. The fuel cell system is sized using simplified mathematical expressions considering the stack degradation and the system salvage value at the end of its life time. The study is based on a 5 kWh/day residential loads with a peak load power of 1300W. Two scenarios for economic survey are studied. The first scenario is to find the commercial price for each FC component considering that the supply fuel is hydrogen. The other scenario is for a complete FC system commercial price considering that the supply fuel is natural gas. The economic analyses are based on the actual sale prices in the market. The COE of the fuel cell system is compared with previous work by the authors for the same residential ratings but supplied from a stand-alone photo voltaic system (SAPV). The analysis results show that the COE relies heavily on the capital cost of the system.

• Vibration Analysis and Optimal Design of Pneumatic Circuits Using Artificial Neural Networks

  1-9.

  Şahin Yildirim

  Asli Durmuşoğlu

  Views:

  109

  Pneumatic systems are commonly used in industry processes and applications of automotion. These systems are make attractive power transmission with the compressed air, because of they are economic, clear, safe and simple structured.So in this systems, as noise and vibration effects, it’ s undesirable situations both human health and system performances yield and working life. In this study, vibration and noise datas are obtained from two type of pneumatic systems prototype which are classify metal and non-metal materials and performed an analysis with help of this datas and used neural network which has adaptive and quick contruction.

• Analysis of A Tilting Table with Parallel Kinematics

  1-5

  István Tüske

  György Hegedűs

  Views:

  131

  This paper presents a workpiece moving unit with parallel kinematics, where its kinematic model is described. Based on the Chebyshev-Grübler-Kutzbach mobility equation the mobility properties of the mechanism are examined. Using the modified Chebyshev-Grübler-Kutzbach criterion the number of degrees of freedom of the workpiece tilting table is determined, after this the screw theory will be presented. As the Chebyshev-Grübler-Kutzbach criterion does not take into account the geometrical characteristics of the examined structure, using the screw theory the workpiece tilting unit will be reanalysed, to take geometrical characteristics into account in determining the degrees of freedom of the structure. Finally, the results of the two theories will be compared in the study of the given kinematic model.

• Design of Neural Predictor for Performance Analysis of Mountain Bicycles

  1-6.

  Şahin Yildirim

  Menderes Kalkat

  Views:

  151

  In recent years, bicycle races, along with the crest of the high technology continues to increase. Because of this increased races, performance of bicycles, in both biological and mechanical terms, is extraordinarily important and efficient. In terms of the ratio of cargo weight a bicycle can carry to total weight, it is also a most efficient means of cargo transportation. In spite of advanced technology, there are still some problems on bicycles during working conditions and road roughness such as on the mountain from tire and mechanical parts. In this investigation, a extraordinary designed with fiber-carbon body and light bicycle is tested on mountain road conditionswith prescribed trajectory on the mountain for different elevation, speed, hearth rate, bike cadence and average temperature. The real time measured parameters are predicted with proposed two types of neural networks for approaching real time neural network predictors. The results of the proposed neural network have shown that neural predictor has superior performance to adopt the real time bicycle performance.

• The Trivial Servomotor and Servo Control System Expressions

  1-4

  Csaba Szász

  Views:

  143

  In electrical engineering the technical terms “servomotor” and “servo control system” are used since long decades ago. They are generally accepted and wide-range used denominations worldwide in scientific papers, books, advertisements and other publications. In other words, the above two terms become somewhat self-understanding incontestable parts of our technical language. However, this paper emphasizes the idea to discuss the exact and real meaning of these two terms. This because often it happens that in scientific publications there is no made clear difference between the terms “motor” or “servomotor”, respectively “control system” or “servo control system” and that may be a real source of misunderstandings or confusions. For this reason, in first step a thorough overview of the available international scientific literature is presented in the paper in order to evidence the context and conditions in that are used the discussed scientific expressions. Then a careful analysis from technical point of view is unfolded to bring arguments to strengthen the endeavor that a clear difference should be made between the terms “motor” and “servomotor”, respectively “control system” and “servo control system” in demanding technical discussions, as well as in scientific publications. Not at least, there is proposed an original definition of the two discussed terms, reflecting a point of view that may contribute to better understanding and utilization in scientific debates and publications.

• Time Domain Analysis and Spectral Methods for Determining Rotational Speed of Rotary Machines

  1-8.

  Gábor Gárdonyi

  Krisztián Samu

  Views:

  64

  Accurate estimation of rotational speed of rotary machines has usually high priority in technical applications. This information should be calculated for many diagnostic algorithms, control or regulation processes. Incorrectly estimated values could occur serious disturbances in the operation of machines. Additional instrumentation often may be obstructed due to lack of space, but the construct of the machine may also affect the accuracy of measurement. In such cases, vibration diagnostic tools can be the disposal of difficulty. Mounting an acceleration sensor onto the outer surface of the measured device is not a major challenge. In most cases using time, frequency or quefrency domain analysis, it is possible to estimate the rotational speed of the analysed rotary machine. The calculated spectra and cepstra can help to determine the rotational speed more easily and more accurate than the time domain methods. This paper presents the comparison of these methods in terms of their usability and rotational speed estimation accuracy. A possible error of traditional optical measurement due to misalignment and benefits of the other methods are illustrated in this article via measured data series of a Brushless DC (BLDC) motor driven system.

• Development of Portable Measuring System for Testing of Electrical Vehicle’s Heat Energy Recovery System

  1-4.

  Kornél Sarvajcz

  Angela Váradiné Szarka

  Views:

  72

  Nowadays the consumer society applies a huge amount of energy in many fields including the transportation sector. The application of the internal combustion vehicles contribute substantially to the air pollution. An alternative solution for reducing energy consumption is replacing the internal combustion vehicles by electrical or hybrid vehicles. Today one of the biggest disadvantages of the electrical vehicles is the finite capacity of batteries. The research topic presented in this paper is the „Energy Harvesting”, and development of energy recovery system for electrical vehicles which largely contributes in increasing the driving range. At the current phase of the research efficiency analysis of the heat energy recovery devices are investigated in real driving circumstances. Computer based mobile and wireless measurement system for the analysis was developed, tested and installed in a real vehicle. Driving tests were performed and analysed in different circumstances.

• Performance Analysis of An Experimental Micro Flexible Manufacturing System (FMS)

  1-8.

  Şahin Yildirim

  Osman Yücel

  Views:

  84

  Due to advanced technology, it is very important the performance of FMS for sensivity, production quality, repeatability and energy consumptions. Flexible manufacturing systems (FMSs) are the most automated and technologically sophisticated of the machine cell types used to implement cellular manufacturing. An FMS usually has multiple automated stations and is capable of variable routings among stations, while its flexibility allows it to operate as a mixed model system. The FMS concept integrates many of the advanced technologies that we met in previous units, including flexible automation, CNC machines, distributed computer control, and automated material handling and storage.

  In this experimental investigation, vibration and accelerations analysis of an experimental FMS with 5 degrees of freedom robot manipulator are presented. Firstly, experimental measurement of accelerations and vibrations are trained with a vibration measurement system and sensors. However, the process of production of part is a cycle of exact production time.

• The Effect of Air-fuel Equivalence Ratio Change on the Vibration Components of an Internal-combustion Engine

  1-6.

  Gabor Manhertz

  Akos Antal

  Views:

  69

  Nowadays the automotive industry and the motor development are one of the most dynamically developing industries. One solution to the diagnostic systems providing reliability is the acoustic and vibration measurement system, which can indicate and predict a variety of malfunctions after signal processing. The purpose of this experiment is to analyze the effect of the air-fuel equivalence ratio on the vibration components of an internal-combustion engine (ICE) which is a part of the in question measurement system. In the focus of the experiments are the analysis of the time signal, its spectra, and the power content of the signal. With the increment of the air-fuel ratio the amplitudes of the measured signal and its spectral amplitudes showed a downward trend as the RMS values. In addition, certain frequency components disappeared during the actuation of the ICE with an electromotor, so the characterization of the combustion could be come to the front.

• Noise and Performances Analysis of Commerical Aircrafts using Artificial Neural Networks

  1-6.

  Şahin Yildirim

  Views:

  69

  Commerical aircrafts are very important part for airway travelling. In spite of high technology on aircrafts, there is still fatality accidents in the world. Because of this reason, it is very important criteria to analyse noises of main elements of the air-craft systems. In tis study, an aircraft’s main disturbances are analysed with proposed neural networks. Firstly, the noises of the jet, turbine and fan were measured from the aircraft. Secondly, the measured parameter values were predicted the proposed neural networks. The results of the proposed neuarl approaches were shown that this type of neural predictors will be employed to predict aircrafts unpredicted disturbances in real time applications.

• Simulation and Formal Verification for Improving Safety of PLC Programs

  1-6.

  Joel Galvão

  José Machado

  Views:

  74

  The use of analysis techniques for improving quality of software for industrial controllers is widely used. Mainly Simulation and Formal Verification can be used as complementary techniques improving dependability of mechatronic systems behavior. In this paper there are used Simulation and Formal Verification for guaranteeing safe software for Programmable Logic Controllers, mainly related with using Function blocks of IEC 61131-3 standard. For studying, simulating and verifying behavior of those blocks are used timed automata, as modeling formalism, and UPPAAL, as tool for simulation and Formal Verification purposes.

• Measurement of the Effect of Chromaticity and Intensity on Colour Representation Parameters of a CRT Display

  1-4.

  Klára Wenzel

  Ágnes Urbin

  Views:

  60

  The aim of the measurement detailed in this paper was to measure the just-noticable stimuli of the participating subjects. The stimuli were defined by chromaticity and intensity as the main parameters of the mathematical model. The results show correlance between intensity and the just-noticable stimuli, as described in the Weber-Frechner Law but a contradiction was shown after the analysis in the function of chromaticity. This contradiction can be explained by the difference between the sensitivity of the three cones of the eye.