Pavol Liptai

USING OF SOUND VISUALISATION TECHNIQUES FOR IDENTIFICATION AND ANALYSIS OF VEHICLE NOISE SOURCES

Urgency of the research. The use of continuous measurement on the roads and highways with noise visualization techniques can in the future lead to increasing road safety. Central computer system could for example, evaluate the information continuously and the feedback would have warned drivers, through their mobile phones or GPS, to replace tires in the nearest dealer or car service. Vehicles fault diagnosis is currently carried out by different devices in car services. In terms of increasing the efficiency, diagnostic methods can be extended for noise visualization techniques. Target setting. Using of measuring devices (for noise visualization) in car services for faster detection of faults and damaged parts as well as based on the measured values of noise pressure level, could be evaluated, if the tires are still safe or not. Actual scientific researches and issues analysis. Acoustic cameras and various noise visualization techniques are implemented to manufacturing process of passenger car manufacturers. Their use is for detecting errors and for reduction of engine noise and its parts as well as car interior. Uninvestigated parts of general matters defining. This article provides only partial research and conclusions. Philosophy, to use this noise visualization technique in many cases is different. The research objective. The aim of this study was to demonstrate the differences in sound levels between two vehicles Skoda Octavia at different speeds at the same road. Partial output is a frequency analysis and identification of dominant sound sources in the engine space of VW Golf 1.4 vehicle. The statement of basic materials. The methods of dynamic visualization of noise are used all around the world. In our case, we used the acoustic camera to visualize and identify the sound sources of moving vehicle as well sources of noise in the engine space. Conclusions. It has been found that vibration from the engine are transmit by chassis to the interior of vehicle and cause uncomfortable noise. In the future, we expect the use of such measuring devices in car services for faster detection of faults and damaged parts. When passing vehicles and higher speeds, the biggest noise, the pressure wave in the contact tireroad is causing. Differences in noise pressure levels are mainly due to weight, quality of tires, aerodynamics and the shape and size of the tread.

ASSESSMENT OF THE WASHING MACHINES SOUND QUALITY BY THE BINAURAL MEASUREMENT SYSTEMS

161 UDC 534.32; 534.6; 648.23; 159+534 Marek Moravec, Pavol Liptai, Ján Zbojovský, Anna Badidová ASSESSMENT OF THE WASHING MACHINES SOUND QUALITY BY THE BINAURAL MEASUREMENT SYSTEMS Марек Моравець, Павол Ліптай, Ян Збойовський, Анна Бадідова ОЦІНКА ЯКОСТІ ЗВУКУ ПРАЛЬНИХ МАШИН БІНАУРАЛЬНИМИ ВИМІРЮВАЛЬНИМИ СИСТЕМАМИ Марек Моравец, Павол Липтай, Ян Збойовский, Анна Бадидова ОЦЕНКА КАЧЕСТВА ЗВУКА СТИРАЛЬНЫХ МАШИН БИНАУРАЛЬНЫМИ ИЗМЕРИТЕЛЬНЫМИ СИСТЕМАМИ

Proposal of the Sound Insulating Measures for Vibrational Sorter and Verification of the Effectiveness Measures

The paper describes a specific design of the sound insulating enclosure of a vibrating sorter. Recycling aspects have been taken into account when designing the enclosure, because recycled foam has been applied as a sound-absorbing material. An acoustic camera was used to measure, analyze, evaluate and to localise and identify sound sources. The visualization method was used to locate the critical locations of the device and then quantify them. To evaluate the effectiveness of the proposed enclosure, the measurements of the sound parameters were performed before and after the realization soundproofing measure. The measured results show the requested efficiency of the sound insulating enclosure in terms of noise reduction as well as dust near the sorter.

Design and Effectiveness Verification of Sound Reduction Measures in Production Hall

The main aim of the work described in this paper was to design and validate measures to reduce noise levels in a training center. This training center serves for the practical training of students with the focus in the shaping and machining engineering products. Reduction of noise in the training center was mainly due to the clarity and hearing of the spoken word between the lecturer and students, as well as to reduce the risk of hearing damage. In order to reduce noise levels, it was proposed to overlap the training center with a roof structure filled with sound absorbing material in two solutions. The noise absorption coefficient of the selected material was determined on the impedance tube. For verification of effectiveness, measurements of equivalent A sound levels were made before and after realization noise reduction measures. Reduction of equivalent A sound pressure levels after the noise reduction measures are between 15.5 dB and 17.5 dB depending on the measuring point and the operating mode. The effectiveness of the implemented measures reaches a good level, as noise was reduced to the recommended legislative level.

RESEARCH OF SELECTED MECHANICAL PROPERTIES OF THE RECYCLED PLASTIC

Plastics are relatively new materials used in almost all areas of human activity, and also in various branches of live and industries. Given the annually growing produce of plastics, their volume are evenly growing up also in the waste, therefore it is necessary to solve the waste from the increasing volume of waste plastic. The contribution deals with the using and testing of sorted plastic waste. From the plastic waste as a semiproduct is prepared the plastic plates by extruding technology, it means recycled plastics processing and verifying of their selected mechanical properties. It also deals with testing of selected plastic shaped plates. There are mentioned also the most usual impurities in the testing samples, created during the production. Contribution was originated as collaboration with TOPlast, Inc. Kosice.

Particulate Matters Propagation by the Surface Winning

In surface winning particulate matters are generated from a range of site preparation, stockpiling, loading, transportation and processing activities. This article aims to review issues relevant to particulate matters produced by the surface winning and impact on people living near by the quarry. Due to the areal extent of the site and limitations imposed by readily available data, the article has focused upon activities associated with quarry. On the base of obtained data was composed mathematical model of the distribution of particulate matter from the source to the surroundings to visual impact of the quarry and potential impact of the particulate matters. The visualization is shown direction of particulate matters propagation and allows decide on used measures to eliminate negative impact on people and environment.