64 research outputs found
The possibility of traffic accident reconstruction using event data Recorders: A review
UreÄaji za beleženje podataka koriste se u svrhu istraga saobraÄajnih nesreÄa viÅ”e od 20 godina. Neke zemlje su zakonski regulisale njihovu primenu i validan su dokaz u istragama i rekonstrukcijama. MeÄutim, ureÄaji za beleženje se koriste kao izvor informacija, a ne kao baza podataka na osnovu kojih je moguÄe rekonstruisati dogaÄaj. Istraživanja samo pomoÄu ureÄaja za beleženje joÅ” uvek nisu moguÄa zbog odreÄenih pojava, kao i zbog konstruktivnih karakteristika ureÄaja. NauÄnici iz Japana i Poljske testirali su taÄnost podataka iz ureÄaja i na osnovu njih izvrÅ”ili rekonstrukcije udesa. Oba tima su utvrdila da je rekonstrukciju moguÄe izvesti samo u jednostavnim situacijama, poput pravolinijskog udara jednog vozila u drugo. Kada je u udaru viÅ”e uÄesnika, ili je udaru prethodio neki manevar, nije moguÄe utvrditi Å”ta se zaista dogodilo. Neophodan je dalji razvoj ovih ureÄaja, kako bi se poveÄala njihova efikasnost prilikom rekonstrukcije saobraÄajnih nezgoda.Event Data Recorders (EDRs) have been used for the purpose of investigating traffic accidents for more than 20 years. Some countries have regulated their application by law, and they are a valid evidence during investigations and reconstructions. However, recording devices are used as a source of information, not as a database from which it is possible to reconstruct the event. Investigations using only recording devices are still not possible due to the some phenomena that exist, and due to the constructional features of the devices. Scientists from Japan and Poland tested the accuracy of the data from the devices and performed reconstructions of accidents. Both teams have established that it is possible to perform reconstruction only in simple situations, such as a straight-line crash of one vehicle into another. When there are several participants in a crash, or a crash was preceded by a maneuver, it is not possible to determine what really happened. Further development of data recording devices is necessary, in order to increase their efficiency during the reconstruction of traffic accidents
The possibility of traffic accident reconstruction using event data Recorders: A review
UreÄaji za beleženje podataka koriste se u svrhu istraga saobraÄajnih nesreÄa viÅ”e od 20 godina. Neke zemlje su zakonski regulisale njihovu primenu i validan su dokaz u istragama i rekonstrukcijama. MeÄutim, ureÄaji za beleženje se koriste kao izvor informacija, a ne kao baza podataka na osnovu kojih je moguÄe rekonstruisati dogaÄaj. Istraživanja samo pomoÄu ureÄaja za beleženje joÅ” uvek nisu moguÄa zbog odreÄenih pojava, kao i zbog konstruktivnih karakteristika ureÄaja. NauÄnici iz Japana i Poljske testirali su taÄnost podataka iz ureÄaja i na osnovu njih izvrÅ”ili rekonstrukcije udesa. Oba tima su utvrdila da je rekonstrukciju moguÄe izvesti samo u jednostavnim situacijama, poput pravolinijskog udara jednog vozila u drugo. Kada je u udaru viÅ”e uÄesnika, ili je udaru prethodio neki manevar, nije moguÄe utvrditi Å”ta se zaista dogodilo. Neophodan je dalji razvoj ovih ureÄaja, kako bi se poveÄala njihova efikasnost prilikom rekonstrukcije saobraÄajnih nezgoda.Event Data Recorders (EDRs) have been used for the purpose of investigating traffic accidents for more than 20 years. Some countries have regulated their application by law, and they are a valid evidence during investigations and reconstructions. However, recording devices are used as a source of information, not as a database from which it is possible to reconstruct the event. Investigations using only recording devices are still not possible due to the some phenomena that exist, and due to the constructional features of the devices. Scientists from Japan and Poland tested the accuracy of the data from the devices and performed reconstructions of accidents. Both teams have established that it is possible to perform reconstruction only in simple situations, such as a straight-line crash of one vehicle into another. When there are several participants in a crash, or a crash was preceded by a maneuver, it is not possible to determine what really happened. Further development of data recording devices is necessary, in order to increase their efficiency during the reconstruction of traffic accidents
The influence of tractor's roll-over protective structure to increased safety of operators in exploitation
Bezbednosni parametri u eksploataciji traktora imaju veoma veliki znaÄaj Jedan od najznaÄajnijih elemenata koji utiÄu na bezbednost rukovalaca u eksploataciji traktora su zaÅ”titne strukture i kabine. U zavisnosti od vrste, namene i kategorije traktora, ugraÄuju se razliÄite vrste zaÅ”titnih struktura ili kabina. U okviru rada prikazana su konstruktivna reÅ”enja zaÅ”titnih struktura, sa osnovnim karakteristikama i primerima ugradnje na traktore, kao i tehnoloÅ”ka izvoÄenja. Danas se u svetu pridaje sve veÄa pažnja poveÄanju udobnosti rukovalaca u eksploataciji. Traktori postaju sve vise prijatno mesto za rad, jer se pored klima ureÄaja, radio aparata i zvuÄne izolacije vodi raÄuna i o ergonomskim zahtevima i lakom komandovanju i upravljanju. DomaÄi proizvoÄaÄi traktora prihvatili su ove savremene trendove i kroz njihovu implementaciju na veÄ postojeÄe i nove proizvode postaju konkurentni na svetskom tržiÅ”tu, Äime u odreÄenoj meri vraÄaju ugled naÅ”oj motornoj industriji.Safety parameters have very big importance during tractor exploitation. One of the most important elements of operator's safety in tractor exploitation are rollover protective structures and cabs. Different types of protective structures and cabs are fitted on tractors, depending of their type, design and category. Different constructions of protective structures and cabs are presented in this paper, with basic characteristics and examples of fitting on tractors, as well as production process technologies. More and more attention in the world today is paid for increase of operator's comfort in exploitation. Tractors became more pleasant places for work, because beside air conditioning system, music systems and noise protection, a lot of attention is intended to ergonomic requests and easy handling. Domestic tractor producers accepted these modern trends and with its implementation to presented and new products they became competitive on the world market helping to bring back the respect to our motor industry
The influence of tractor's roll-over protective structure to increased safety of operators in exploitation
Bezbednosni parametri u eksploataciji traktora imaju veoma veliki znaÄaj Jedan od najznaÄajnijih elemenata koji utiÄu na bezbednost rukovalaca u eksploataciji traktora su zaÅ”titne strukture i kabine. U zavisnosti od vrste, namene i kategorije traktora, ugraÄuju se razliÄite vrste zaÅ”titnih struktura ili kabina. U okviru rada prikazana su konstruktivna reÅ”enja zaÅ”titnih struktura, sa osnovnim karakteristikama i primerima ugradnje na traktore, kao i tehnoloÅ”ka izvoÄenja. Danas se u svetu pridaje sve veÄa pažnja poveÄanju udobnosti rukovalaca u eksploataciji. Traktori postaju sve vise prijatno mesto za rad, jer se pored klima ureÄaja, radio aparata i zvuÄne izolacije vodi raÄuna i o ergonomskim zahtevima i lakom komandovanju i upravljanju. DomaÄi proizvoÄaÄi traktora prihvatili su ove savremene trendove i kroz njihovu implementaciju na veÄ postojeÄe i nove proizvode postaju konkurentni na svetskom tržiÅ”tu, Äime u odreÄenoj meri vraÄaju ugled naÅ”oj motornoj industriji.Safety parameters have very big importance during tractor exploitation. One of the most important elements of operator's safety in tractor exploitation are rollover protective structures and cabs. Different types of protective structures and cabs are fitted on tractors, depending of their type, design and category. Different constructions of protective structures and cabs are presented in this paper, with basic characteristics and examples of fitting on tractors, as well as production process technologies. More and more attention in the world today is paid for increase of operator's comfort in exploitation. Tractors became more pleasant places for work, because beside air conditioning system, music systems and noise protection, a lot of attention is intended to ergonomic requests and easy handling. Domestic tractor producers accepted these modern trends and with its implementation to presented and new products they became competitive on the world market helping to bring back the respect to our motor industry
A methodology for redirected design of bus superstructures regarding their strength
Prevrtanje predstavlja jedan od najÄeÅ”Äih vidova autobuskih nezgoda. Parametri
bezbednosti autobusa uzimaju u obzir, izmeÄu ostalog, veliki broj putnika koji se
istovremeno nalaze u autobusu, ograniÄeni broj mera pasivne bezbednosti koje se
mogu koristiti (sigurnosni pojasevi, vazduŔni jastuci, itd.), kao i relativno loŔu
boÄnu stabilnost ovih vozila. Zbog toga zahtevi za konstrukciju autobusa ukljuÄuju
reŔenja za poboljŔanje bezbednosti vozila protiv prevrtanja, kao deo procesa
projektovanja.
U okviru doktorske disertacije predstavljen je razvijeni metodoloŔki pristup
formiranja modularnih prstenova nadgradnje, koji predstavljaju osnovne noseÄe
elemente ÄvrstoÄe konstrukcije. PoÄetne aktivnosti zasnivaju se na definisanju
zona plastiÄnih deformacija prilikom prevrtanja i odreÄivanju karakteristika
lociranih plastiÄnih zglobova. Zatim se formiraju diskretizovani numeriÄki gredni
modeli, sa eksperimentalno definisanim karakteristikama i poznatim vrednostima
apsorbovane energije. Dobijeni rezultati omoguÄavaju ukljuÄenje diskretizovanih
modela u dalji proces projektovanja, gde se kroz viÅ”i nivo numeriÄke analize
dobijaju osnovne karakteristike modularnih prstenova nadgradnje. KonaÄno,
pretpostavljena metodologija potvrÄena je eksperimentalnom verifikacijom na
realnom fiziÄkom modelu prstena nadgradnje.Rollover is among the most common form of bus accidents. Bus safety issues
include, among others, the large number of passengers that can be in a bus at the
same time, limited extent to which passive safety measures (safety belts, airbags,
etc.) can be used, and a relatively low rollover stability of this type of vehicle. Bus
construction requirements therefore include solutions for improved rollover
safety as a part of the design process.
Within this dissertation, the developed methodological approach of superstructure
modular rings forming is presented, which represent basic elements of
superstructure strength. Starting activities are based on defining of plastic
deformation zones during rollover and determination of located plastic hinges
characteristics. Then, discretized numerical beam models are formed, with
experimentaly defined characteristics and calculated values of absorbed energy.
Achieved results enable implementation of discretized models into the further
designing process where, through higher level of numerical analysis, we can get
basic characteristics of superstructure modular rings. Finally, assumed
methodology has been confirmed with experimental verification on real physical
model of superstructure modular ring
A methodology for redirected design of bus superstructures regarding their strength
Prevrtanje predstavlja jedan od najÄeÅ”Äih vidova autobuskih nezgoda. Parametri bezbednosti autobusa uzimaju u obzir, izmeÄu ostalog, veliki broj putnika koji se istovremeno nalaze u autobusu, ograniÄeni broj mera pasivne bezbednosti koje se mogu koristiti (sigurnosni pojasevi, vazduÅ”ni jastuci, itd.), kao i relativno loÅ”u boÄnu stabilnost ovih vozila. Zbog toga zahtevi za konstrukciju autobusa ukljuÄuju reÅ”enja za poboljÅ”anje bezbednosti vozila protiv prevrtanja, kao deo procesa projektovanja. U okviru doktorske disertacije predstavljen je razvijeni metodoloÅ”ki pristup formiranja modularnih prstenova nadgradnje, koji predstavljaju osnovne noseÄe elemente ÄvrstoÄe konstrukcije. PoÄetne aktivnosti zasnivaju se na definisanju zona plastiÄnih deformacija prilikom prevrtanja i odreÄivanju karakteristika lociranih plastiÄnih zglobova. Zatim se formiraju diskretizovani numeriÄki gredni modeli, sa eksperimentalno definisanim karakteristikama i poznatim vrednostima apsorbovane energije. Dobijeni rezultati omoguÄavaju ukljuÄenje diskretizovanih modela u dalji proces projektovanja, gde se kroz viÅ”i nivo numeriÄke analize dobijaju osnovne karakteristike modularnih prstenova nadgradnje. KonaÄno, pretpostavljena metodologija potvrÄena je eksperimentalnom verifikacijom na realnom fiziÄkom modelu prstena nadgradnje.Rollover is among the most common form of bus accidents. Bus safety issues include, among others, the large number of passengers that can be in a bus at the same time, limited extent to which passive safety measures (safety belts, airbags, etc.) can be used, and a relatively low rollover stability of this type of vehicle. Bus construction requirements therefore include solutions for improved rollover safety as a part of the design process. Within this dissertation, the developed methodological approach of superstructure modular rings forming is presented, which represent basic elements of superstructure strength. Starting activities are based on defining of plastic deformation zones during rollover and determination of located plastic hinges characteristics. Then, discretized numerical beam models are formed, with experimentaly defined characteristics and calculated values of absorbed energy. Achieved results enable implementation of discretized models into the further designing process where, through higher level of numerical analysis, we can get basic characteristics of superstructure modular rings. Finally, assumed methodology has been confirmed with experimental verification on real physical model of superstructure modular ring
The future (and the present) of motor vehicle propulsion systems
Limited reserves of oil and the increasing environmental effect of its usage as a motor fuel represent global issue related to the constantly increasing number of motor vehicles. Therefore, the reduction of the fossil fuel consumed and the emission produced in internal combustion engines is the primary goal of the development of motor vehicle propulsion systems. In that sense, the present and the future of motor vehicles relies on hybrid drive systems, electric drive systems and drive systems which use hydrogen as a fuel (either by its combustion or by production of electric energy with the help of fuel cells). In this paper, the authors have presented the aforementioned motor vehicle propulsion systems by explaining their function and design, their basic elements and their functions. Authors have also analysed advantages and disadvantages of the mentioned propulsion systems in comparison to conventional internal combustion engine based systems, both technically and environmentally speaking, but also in relation to available infrastructure and energy resources
Advanced theoretical-experimental method for optimization of dynamic behavior of firefighting vehicle modular superstructures
U radu je predstavljena teorijsko-eksperimentalna metoda razvijena sa ciljem optimizacije dinamiÄkog ponaÅ”anja modularnih nadgradnji vatrogasnih vozila. TeÅ”ki uslovi eksploatacije u kojima se vatrogasna vozila koriste, kao i posebni zahtevi za ovu vrstu vozila zahtevaju posveÄenost u pristupu optimizaciji nadgradnji sa stanoviÅ”ta napona, deformacija, zamora, buke, kao i udobnosti i efektivnosti vozila. Optimizacija podrazumeva izbor optimalnih oblika, materijala, dimenzija, veza, oslanjanja, priguÅ”enja i izolacije modula, sa ciljem postizanja optimalnog dinamiÄkog ponaÅ”anja nadgradnje. Metoda opisana u radu sastoji se od dva meÄusobno povezana dela - teorijskog i eksperimentalnog. Teorijski deo sastoji se od numeriÄkog modeliranja varijanti nadgradnje i proraÄuna odziva na dinamiÄke pobude koriÅ”Äenjem metode konaÄnih elemenata, Äiji se rezultati naknadno verifikuju kroz eksperimente. Eksperimentalni deo zasniva se na pobudi fiziÄkih modela nadgradnji pomoÄu posebno razvijenog mehaniÄkog pobudnog ureÄaja, praÄenju odziva nadgradnji, kao i promeni ulaznih parametara u procesu projektovanja nadgradnji, sa ciljem dobijanja nadgradnje sa Å”to boljim dinamiÄkim karakteristikama. Sopstvene frekvencije nadgradnje, važne u smislu rezonantnih zona, dobijene su koriÅ”Äenjem testa udarom i FFT analize. Ova metoda se pokazala adekvatnom za optimizaciju dinamiÄkog ponaÅ”anja modularnih nadgradnji, kao Å”to su one kod vatrogasnih vozila. Celokupna ispitna instalacija koriÅ”Äena kroz ovu metodu ilustrativno je prikazana u radu. TakoÄe, date su smernice za dalje aktivnosti, razvoj i unapreÄenje ove metode.This paper shows elaborated theoretical-experimental method used to optimize dynamic behavior of modular superstructures of firefighting vehicles. Harsh exploitation conditions under which firefighting vehicles operates and special requirements for this type of vehicles require dedicated approach to optimization of superstructures in terms of stress, deformation, fatigue, noise, comfort and effectiveness. Optimization implies selection of optimal shapes, materials, dimensions, mountings, suspension, damping and insulation of modules to attain optimal dynamic behavior of superstructure. Method described in this paper can be divided into two interconnected parts - theoretical and experimental. Theoretical part consists of numerical modeling of superstructure variants and calculation of their responses to dynamic excitations using FEM, whose results are later validated through experiments. Experimental part of this method is based on excitation of superstructure physical models with, for this purpose specially developed, mechanical exciter, monitoring of superstructure response and changing of the input parameters in the design of superstructure to create the superstructure with best possible dynamic characteristics. Natural frequencies of structures, important in terms of resonant zones, are obtained using bump tests and FFT analysis. This method has proved suitable for optimization of dynamic behavior of modular superstructures such as those of firefighting vehicles. Complete testing installation used in this method is illustratively shown in this paper. Also, there are guidelines for further development and improvement of this method
Advanced theoretical-experimental method for optimization of dynamic behavior of firefighting vehicle modular superstructures
U radu je predstavljena teorijsko-eksperimentalna metoda razvijena sa ciljem optimizacije dinamiÄkog ponaÅ”anja modularnih nadgradnji vatrogasnih vozila. TeÅ”ki uslovi eksploatacije u kojima se vatrogasna vozila koriste, kao i posebni zahtevi za ovu vrstu vozila zahtevaju posveÄenost u pristupu optimizaciji nadgradnji sa stanoviÅ”ta napona, deformacija, zamora, buke, kao i udobnosti i efektivnosti vozila. Optimizacija podrazumeva izbor optimalnih oblika, materijala, dimenzija, veza, oslanjanja, priguÅ”enja i izolacije modula, sa ciljem postizanja optimalnog dinamiÄkog ponaÅ”anja nadgradnje. Metoda opisana u radu sastoji se od dva meÄusobno povezana dela - teorijskog i eksperimentalnog. Teorijski deo sastoji se od numeriÄkog modeliranja varijanti nadgradnje i proraÄuna odziva na dinamiÄke pobude koriÅ”Äenjem metode konaÄnih elemenata, Äiji se rezultati naknadno verifikuju kroz eksperimente. Eksperimentalni deo zasniva se na pobudi fiziÄkih modela nadgradnji pomoÄu posebno razvijenog mehaniÄkog pobudnog ureÄaja, praÄenju odziva nadgradnji, kao i promeni ulaznih parametara u procesu projektovanja nadgradnji, sa ciljem dobijanja nadgradnje sa Å”to boljim dinamiÄkim karakteristikama. Sopstvene frekvencije nadgradnje, važne u smislu rezonantnih zona, dobijene su koriÅ”Äenjem testa udarom i FFT analize. Ova metoda se pokazala adekvatnom za optimizaciju dinamiÄkog ponaÅ”anja modularnih nadgradnji, kao Å”to su one kod vatrogasnih vozila. Celokupna ispitna instalacija koriÅ”Äena kroz ovu metodu ilustrativno je prikazana u radu. TakoÄe, date su smernice za dalje aktivnosti, razvoj i unapreÄenje ove metode.This paper shows elaborated theoretical-experimental method used to optimize dynamic behavior of modular superstructures of firefighting vehicles. Harsh exploitation conditions under which firefighting vehicles operates and special requirements for this type of vehicles require dedicated approach to optimization of superstructures in terms of stress, deformation, fatigue, noise, comfort and effectiveness. Optimization implies selection of optimal shapes, materials, dimensions, mountings, suspension, damping and insulation of modules to attain optimal dynamic behavior of superstructure. Method described in this paper can be divided into two interconnected parts - theoretical and experimental. Theoretical part consists of numerical modeling of superstructure variants and calculation of their responses to dynamic excitations using FEM, whose results are later validated through experiments. Experimental part of this method is based on excitation of superstructure physical models with, for this purpose specially developed, mechanical exciter, monitoring of superstructure response and changing of the input parameters in the design of superstructure to create the superstructure with best possible dynamic characteristics. Natural frequencies of structures, important in terms of resonant zones, are obtained using bump tests and FFT analysis. This method has proved suitable for optimization of dynamic behavior of modular superstructures such as those of firefighting vehicles. Complete testing installation used in this method is illustratively shown in this paper. Also, there are guidelines for further development and improvement of this method
System Approach to Vehicle Suspension System Control in CAE Environment
In recent years, motor vehicles industry has shown a tendency of replacing electromechanical components by mechatronic systems with intelligent and autonomous properties. The integration of hardware components and implementation of advance control function characterize this replacement. In this paper we have applied the system approach and system engineering methods in the initial phase of vehicle active suspension development. An emphasis has been placed upon the interrelations between computer-aided simulation and other elements of the development process. The benefits of application of active suspension simulation are numerous: reduction of time to market, the new and improved functions of mechatronic components/devices, as well as the increased system reliability. In suspension model development, we used CAD/CAE tools, as well as the multipurpose simulation programs. For simulation, we used the one-quarter vehicle model. The modelling was carried out through the state-space equation, after which we designed the controller for our system. During this, we considered only the digital systems of automatic regulation
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