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EN
Vehicle emissions and performance fueled with waste cooking oil biodiesel is the main topic of this research. Biodiesel was produced through transesterification with physical and chemical characteristics comparable to diesel. B20 is a methyl ester of 20% blended with diesel. A diesel vehicle was modified and equipped with all measuring instruments needed to perform all experiments. The variable speed and load tests were conducted on the vehicle to measure the performance and emissions at different loads (0–30 kW) and different speeds (0–33 km/h). The vehicle speed was the maximum attained for each gear with a constant fuel flow rate without external fuel control at a steady state. At a vehicle speed of 33 km/h, the greatest increases in fuel consumption and exhaust gas temperature for biodiesel B20 were 17 and 6%, respectively, as related to pure diesel. At a vehicle speed of 33 km/h, B20 reduced the distance traveled, carbon monoxide and hydrocarbon concentrations compared to diesel by 22, 9 and 10%, respectively. At a vehicle speed of 33 km/h, the increases in nitrogen oxides and oxygen concentrations of B20 were 4 and 3% higher, respec-tively, than crude diesel over the whole tested load range. The biggest increases in distance, fuel consumption, and exhaust gas temperature for B20 over diesel were 13, 3, and 2%, respectively, at a vehicle load of 30 kW. The B20 blend decreased CO and hydrocarbon emissions related to diesel by 17 and 32%, respectively, at a vehicle load of 30 kW. The increases in nitrogen oxides and oxygen concentrations of B20 across the whole load range were 11 and 3% higher than pure diesel at a vehicle load of 30 kW, respectively. Biodiesel blend B20 is suggested for application in vehicles providing that the vehicle is moderately loaded.
PL
Głównym tematem badań podjętych w niniejszym artykule są emisje i osiągi pojazdów napędzanych biodieslem odpadowym z oleju spożywczego. Biodiesel powstał w procesie transestryfikacji o właściwościach fizycznych i chemicznych porównywalnych z olejem napędowym. B20 to 20% ester metylowy zmieszany z olejem napędowym. Zmodyfikowano pojazd z silnikiem diesla i wyposażono go we wszystkie przyrządy pomiarowe potrzebne do przeprowadzenia wszystkich eksperymentów. Przeprowadzono testy zmiennej prędkości i obciążenia pojazdu, aby zmierzyć jego osiągi i emisję przy różnych obciążeniach (0–30 kW) i różnych prędkościach (0–33 km/h). Prędkość pojazdu była maksymalną osiąganą na każdym biegu przy stałym natężeniu przepływu paliwa bez zewnętrznego sterowania paliwem w stanie ustalonym. Przy prędkości pojazdu wynoszącej 33 km/h największe wzrosty zużycia paliwa i temperatury spalin dla biodiesla B20 wyniosły odpowiednio 17 i 6% w porównaniu do czystego oleju napędowego. Przy prędkości pojazdu wynoszącej 33 km/h B20 zmniejszył przebyty dystans oraz stężenie tlenku węgla i węglowodorów w porównaniu do oleju napędowego odpowiednio o 22, 9 i 10%. Przy prędkości pojazdu wynoszącej 33 km/h przyrosty stężeń tlenków azotu i tlenu B20 były w całym badanym zakresie obciążeń odpowiednio o 4 i 3% większe niż w przypadku surowego oleju napędowego. Największy wzrost zasięgu, zużycia paliwa i temperatury spalin dla B20 w porównaniu z olejem napędowym wyniósł odpowiednio 13, 3 i 2% przy obciążeniu pojazdu 30 kW. Mieszanka B20 zmniejszyła emisję CO i węglowodorów związaną z olejem napędowym odpowiednio o 17 i 32% przy obciążeniu pojazdu 30 kW. Wzrosty stężeń tlenków azotu i tlenu B20 w całym zakresie obciążenia były odpowiednio o 11 i 3% wyższe niż w przypadku czystego oleju napędowego przy obciążeniu pojazdu 30 kW. Mieszankę biodiesla B20 zaleca się stosować w pojazdach pod warunkiem, że pojazd jest umiarkowanie obciążony.
EN
In recent years, the development of container transportation served as a powerful impetus for increasing the length of vehicles, especially road trains, which is due to a number of advantages regarding the transportation of large-sized freight in a container. Today, the whole range of containers is transported by two-link road trains consisting of a tractor vehicle and semi-trailer. The efficiency of such transportation can be increased by means of three-link road trains capable of transporting either three (two 20-foot and one 40- or 45-foot) or four 20-foot containers. This organization of transportation will lead to energy savings and a reduction in environmental pollution due to the reduction of vehicles. However, there is a problem with the maneuverability and stability of such vehicles. The paper developed a kinematic model of three-link road train type “B-triple” with steered axles (front or rear) of semi-trailer dolly with a dual drive control for these axles. Based on folding angles of road train links and drive control transmission ratios of the axles of semi-trailer dolly, the main indicators of road train maneuverability are determined – road train links trajectories displacement relative to the vehicle trajectory and road train overall traffic lane. It was established that when entering a turn with slight differences in folding angles of road train links, the steered axles of semi-trailer dolly turn in the direction opposite to the direction of a turn, thereby reducing the overall traffic lane. During circular motion, the overall traffic lane of road train with steered semi-trailers decreased by almost 2 m, but such road train does not meet the maneuverability requirements. The search for ways to improve the maneuverability of three-link road trains should be sought in the designs of three-link road trains.
PL
Artykuł podejmuje problematykę poprawy efektywności dostaw ładunków w zabytkowych centrach dużych miast i aglomeracji przy wykorzystaniu rowerów towarowych. Stanowi on opis wybranych zagadnień wchodzących w zakres rozprawy doktorskiej autora [1]. W artykule zaprezentowano model matematyczny systemu dostaw, w ramach którego zidentyfikowane zostały następujące elementy: kryterium oceny efektywności systemu, model popytu na dostawę ładunków, metody trasowania pojazdów oraz metody wyboru lokalizacji punktów przeładunkowych. Wszystkie elementy zostały scharakteryzowane w późniejszych częściach tekstu. Zaproponowano podejście do ewaluacji systemów dostaw ładunków poprzez identyfikację wskaźnika oceny efektywności uwzględniającego wymiar ekonomiczny procesu technologicznego oraz założenia strategii zrównoważonego rozwoju. Sformalizowano sposób obliczenia poszczególnych składowych wskaźnika oceny efektywności. Część badawcza obejmuje charakteryzację dwóch eksperymentów symulacyjnych przeprowadzonych za pomocą specjalnie stworzonego oprogramowania. Pierwszy z nich zrealizowano przy wykorzystaniu zaproponowanej metody analizy statystycznej wskaźnika oceny efektywności oraz heurystycznej metody środka ciężkości. Dotyczył on wyznaczenia lokalizacji punktu przeładunkowego na potrzeby rowerowego systemu dystrybucji. Drugi natomiast polegał na ocenie trzech metod marszrutyzacji (algorytmu oszczędzania Clarke’a–Wrighta, symulowanego wyżarzania i algorytmu genetycznego) w kontekście wartości przyjętego wskaźnika oceny efektywności. Jego przebieg odbywał się zgodnie z opracowanym planem eksperymentu pełno-czynnikowego, uwzględniającego zmienność popytu na przewozy ładunków. Całość zakończono wnioskami płynącymi z zaprezentowanej pracy badawczej, a także zaproponowano dalsze kierunki badań i rozwoju tematyki.
EN
The article deals with the issue of improving the efficiency of cargo delivery in agglomerations, using cargo bikes. It is a description of selected issues falling within the scope of the dissertation with the same title. The article presents a mathematical model of the delivery system, including elements that have been identified: the criterion for evaluating the system’s effectiveness, the model of demand for the cargo delivery, the methods of vehicle routing and the methods of choosing the reloading points’ location. An approach to the evaluation of cargo delivery systems w as proposed by identifying an efficiency assessment indicator, which takes into account the economic dimension of the technological process and the assumptions of the sustainable development strategy. The research includes the characteristics of two simulation experiments. First was conducted using the proposed method of statistical analysis of the effectiveness evaluation indicator and the heuristic method – the center of gravity method. Second was consisted in evaluating three vehicle routing methods. The article was summed up with conclusions from the presented research. Moreover, further directions of research and development of the subject were proposed.
EN
Road freight transport is one of the main modes of transporting goods in the European Union. This reality puts pressure on carriers to make every transport of goods fast, safe, cheap, and efficient. Based on these requirements, lorry drivers are often forced by their employers to break the current social legislation in the European Union and the rules of the road. Compared to the current social legislation in force in different parts of the world, the European Union rules on driving times, breaks and rest periods for drivers engaged in road haulage and passenger transport are the strictest. An important factor and reason of serious and fatal traffic accidents, extensive damage to goods or property in road freight transport is a driver. This article presents three different types of experiments that were carried out, and the results may help to improve the current situation. The main aim of this study was to verify whether the actual regulations are safe and suitable and compare the results of daily work of professional drivers in two different measurements. Last measurement was conducted with using Eye-tacking technology, which aimed to verify impact of experiences on the reaction times of drivers. The authors believe that the results of individual measurements can contribute to increasing safety in road freight transport with preparing future extended studies and proposing the possible changes of current regulation.
EN
Modern city buses are made of various construction materials and the share of material groups has changed over the decades. By replacing heavy materials for structural elements or bus components with their lighter counterparts, the kerb weight of the bus can be reduced by up to several hundred kilograms. This article presents the issues of the development of city bus design in terms of passenger space comfort and bus structure in the context of reducing the vehicle's own weight since the 1970s. The main changes in vehicle design allowing for reducing the weight of structural elements of bodies and chassis as well as the main assemblies in city buses are presented as well as research on body types in terms of aerodynamics, safety and travel comfort. It has been shown that reducing the weight of the bus does not negatively affect its load capacity and the new bus designs are equipped with safety and comfort systems, including ABS (Anti-lock Braking System), ASR (Automatic Stability Regulation), ESP (Electronic Stability Program) and air conditioning in the passenger space. Thanks to modern light construction materials, we gain the opportunity to improve safety and comfort without losing the transport capabilities developed as a result of the development of city buses over the years.
EN
Every year too many people lose their lives and health on Polish roads. At best, it only ends with damage to their cars. The number of accidents is very high. Despite the construction of new, safer roads, the number of collisions continues to rise, and death, every year, is suffered by about three thousand accident participants. On average, forty-one thousand people are injured annually. The main causes of accidents are failure to adjust speed to prevailing conditions or traffic regulations, driving under the influence of alcohol and random events, as well as the technical condition of the vehicles. The purpose of the article is to answer the question of how the technical condition of the vehicles affects traffic safety. For this reason, an assessment of the technical condition of vehicles during a periodic examination at a vehicle inspection station was made. Based on the study, it can be concluded that the largest percentage of defects detected during the examination is in the tire 40% and steering 40%, defects that are particularly important from the point of view of traffic safety, which were demonstrated during the examination.
EN
Presently, we can learn and read more and more about hydrogen in both traditional and social media. The article answers why there is so much interest in hydrogen recently. It has been recognized by European and global decision-makers as a very promising medium necessary to carry out the climate and energy transformation. The advantages of hydrogen as a fuel and as a medium for storing large amounts of energy over a longer period of time is also presented. In addition, an overview of hydrogen technologies presented at the Hydrogen Technology Expo in Bremen in September 2023 is provided. The state of hydrogen technologies currently available on the market is compared to the latest achievements of scientists described in scientific articles. The aim of the article is to review the technologies available on the market for the production, storage and use of hydrogen as a vehicle fuel. Hydrogen technologies presented at the Hydrogen Expo in Bremen were confronted with the latest scientific achievements described in the latest scientific articles. Thanks to such a confrontation, it is possible to make a rational purchasing decision in the area of selected hydrogen technologies.
EN
The aim of the research was to analyse the possibility of using neural networks to determine the parameters of the chemical composition of exhaust gases as a function of engine performance parameters obtained from the on-board diagnostics system such as crankshaft speed and engine load index. The subject of the study was a Fiat Panda car equipped with a 1.3 Multijet diesel engine and powered by pure diesel. The tests used the MAHA MET 6.3 exhaust gas analyser and the on-board diagnostics system OBD II. The obtained values of NOx,O2,CO2 and PM measured behind the DPF were analysed. For the purpose of building a neural network model, preliminary studies were carried out in non-urban traffic (high-speed route). Based on the data obtained, processes of learning neural network structures with approximate properties with backward propagation of errors were carried out. Subsequently, tests were carried out on the operational parameters of the vehicle and the chemical composition of exhaust gases in urban traffic. Analysis of the obtained values of the average parameters obtained during the measurement and obtained on the basis of the prepared neural models allows to determine the relative differences at the level of not more than 10 percent.
EN
The proper technical condition of a vehicle and rail track in operation is a key aspect in terms of safety and travel comfort. This issue is of particular importance for operators and managers of rolling stock and rail infrastructure. Currently, many diagnostic systems have been developed to monitor the technical condition of selected vehicle systems or rail track from the viewpoints of both the vehicle and track. This article proposes the use of vibration signals in selected quantitative and qualitative analyses as the main diagnostic parameter. For this purpose, over a dozen vibration measurements were carried out during the normal operation of a freight wagon as part of a so-called passive experiment. Measurement points were located on the axle boxes of the wheelsets. The proposed research methodology served as a basis for comparative analyses of the selected operational cases that were investigated. The most important conclusion from the study is that it is possible to monitor the technical condition of vehicles and tracks in real time on the basis of measurements of vibration accelerations at the vehicle level. This directly increases the service life of rolling stock and optimises operating costs by changing the maintenance strategy to one that takes into account the idea of modern on-board technical diagnostics. Another important aspect is the possibility of the varied use of the proposed measurement system, depending on the purpose of the research, which is also associated with the diagnostician’s experience in processing vibroacoustic signals and the utilization of simple or complex quantitative and qualitative analyses.
PL
W niniejszym artykule scharakteryzowano krótko elementy systemu człowiek - pojazd - droga. Ponadto przedstawiono wyniki badań dotyczących świadomości osób kierujących pojazdami na temat ważności zagadnień wpływających na bezpieczeństwo ruchu drogowego. Badania miały charakter ankietowy, a ich celem było określenie stopnia świadomości kierujących pojazdami dotyczącej bezpieczeństwa ruchu drogowego w kontekście przyczyn wypadków drogowych i powiązania ich ze stanem technicznym pojazdu oraz stanem infrastruktury drogowej.
EN
In this article, the elements of a system comprising of a human being, vehicle, and road are briefly characterised. In addition, the results of research on the awareness of vehicle drivers of the importance of issues affecting road safety are presented. The research was carried out in the form of a questionnaire, and its aim was to determine the level of awareness of vehicle drivers of road safety in the context of the causes of road accidents and linking them with the technical condition of the vehicle and the state of road infrastructure.
EN
Relevance of the study: As the experience of advanced countries shows, the development of the economy in our country, in particular, in the transportation services market, is associated with the development of interaction between all types of transport. Thus, in modern conditions, for the growth of the role of railway transport, multimodal transportation, which is important for the interaction of Ukraine with the countries of Europe and the East, is becoming important and will also help minimize costs and preserve the environment. Therefore, the issues of evaluating the introduction of multimodal transportation with logistic principles are discussed in the article. It is shown how to determine the marginal substitution rate in the conveyance type while using various modes of transport, based on the utility function and transportation costs. Purpose of the study: The purpose of the article is to develop measures to improve the functioning of parts in multimodal freight delivery routes by minimizing transportation costs, taking into account quality indicators. For this purpose, the following tasks have been set and are being solved: to develop a model for evaluating the efficiency of using different modes of transport with optimal costs; to choose a method for estimating the optimal delivery route and freight volumes; to evaluate the efficiency of transportation technology based on a qualimetric indicator. Approaches: An approach to a comprehensive evaluation of the effect from the activities of transport enterprises in multimodal transportation based on cost optimization, with the qualimetric indicator, and aimed at maximizing the satisfaction of shippers' requirements is offered when determining the route of such transportation parameters as the cost and the quality of freight delivery. Results: The results of the theoretical generalization and analysis of approaches to the formalization of the functioning process in multimodal transportation systems for the delivery of goods by rail and road modes of transport are presented in the article. The significance of the results. The materials in the article are of practical value for employees of transport and logistics companies and enterprises, scientists, and pedagogical workers to improve their professional level.
EN
The aim of the article is focused on assessing the degree of end-of-life for the vehicle front suspension beam. The first stage of the problem taken was represented by a road test of the vehicle at distance expressed by 100.000 km. Following the end of the operation tests, the suspension beam was dismantled and subjected to laboratory tests. The tests demonstrated numerous beam top layer plastic deformations, which came into being as a result of the vehicle driving onto an obstacle on the roadway or onto raised road infrastructure elements. At the point of connection of the stabiliser rod to the beam, surface degradation was noted, which consisted in the considerable change of the surface profile, hardness reduction and the grey and dark brown colour. Corrosion regions and fretting wear traces were noted. Corrosion pits, scratches and material build-ups was observed. The analysis of the chemical composition of wear products demonstrated the presence of elements such as iron, oxygen, chlorine and silicon, as an effect of operational conditions.
EN
The aim of the study is to present the results of mathematically modeled influence of the average speed on the pollutant released in the air during the cold-start process. There were taken into consideration the emission from the passenger cars (PCs) for the different fuel types, vehicles’ segments (including hybrid), and the Euro standard. In the article the simulations was performed using the COPERT software, as well as WLTP-based research. The modelling results there are presented show that the change in average speed has a significant effect on air pollutant (CO2, NOx, NMVOC, CO) emissions released in cold-start process. Furthermore, the results show that pollutants’ emissions are sensitive to average speed fluctuations.
14
Content available System monitorowania stanu bezpieczeństwa pojazdu
PL
Pojazd pozostawiony na parkingu może być celem potencjalnej kradzieży lub uszkodzenia. Aby właściciel miał informację o stanie, w jakim jego pojazd się znajduje, konieczne jest zastosowanie odpowiednich środków ochrony. dlatego opracowano autorski system monitorowania stanu bezpieczeństwa pojazdu. Aby uzyskać odpowiednią informację o stanie zabezpieczanego pojazdu, został wykonany demonstrator systemu. Umożliwia on monitorowanie następujących parametrów: nachylenia pojazdu (wiążącego się na przykład z podniesieniem samochodu w celu umieszczenia go na lawecie), chwilowego przyspieszenia pojazdu (wiążącego się na przykład ze stłuczką na parkingu), lokalizacji GPS (wiąże się z przemieszczeniem pojazdu względem ustalonej pozycji), temperatury oraz wilgotności. Ponadto monitorowany jest ruch w pojeździe poprzez pasywną czujkę podczerwieni, stan drzwi (otwarte/zamknięte) poprzez kontaktrony oraz stężenie gazu (LPG, propan-butan) za pomocą czujnika gazu. informacje o czujnikach pojazdu są wysyłane użytkownikowi w postaci wiadomości sms zarówno na żądanie użytkownika, jak i w postaci alarmu. Zaprojektowany system monitorowania stanu bezpieczeństwa pojazdu jest rozwiązaniem, które umożliwia użytkownikowi zarówno korzystanie, jak i dodawanie nowych przydatnych funkcjonalności. możliwe jest też dodanie kolejnych czujników, a także rozbudowa o innowacyjne funkcje (np. kontrola dostępu). skutkuje to zwiększeniem poczucia bezpieczeństwa użytkownika dotyczącego jego pojazdu.
EN
A vehicle left in a parking lot may be the target of a potential theft or damage. in order for the vehicle owner to have information about the condition of his vehicle, it is necessary to apply appropriate security measures. Therefore, a proprietary vehicle security monitoring system has been developed. in order to obtain adequate information about the condition of the secured vehicle, the vehicle security system has been designed and constructed. it allows you to monitor such parameters as: vehicle inclination (related to, for example, lifting the car in order to put it on a trailer), temporary vehicle acceleration (related to, for example, a car crash in a parking lot), GPS location (related to vehicle displacement in relation to a fixed position), temperature and humidity. in addition, the movement in the vehicle is monitored by a passive infrared detector, the door status (open/ closed) by reed switches, and the gas concentration (LPG, propane butane) by a gas sensor. information about the vehicle sensors is sent to the user in the form of an sms message, either at the user’s request or in the form of an alarm. The designed vehicle security monitoring system is a solution that allows the user to both use and add new useful functionalities. it is also possible to add additional sensors, as well as to expand with new innovative functions (e.g. access control). This results in an increased sense of security for the user regarding his vehicle.
EN
In a conventional internal combustion engine, only electrical controls are used to prepare the fuel mixture. All parts must operate flawlessly in order for the vehicle and its components to operate correctly. Road safety may be negatively impacted by the failure of specific components. The purpose of the study was to ascertain how much the malfunction of particular electrical components affects how the vehicle operates. The vehicle’s individual electronic parts were removed, and the engine power was then assessed. The primary determinant of a vehicle’s technical condition is thought to be its engine power. The preparation of the combustion mixture was affected by the individual component disconnections, which reduced the vehicle’s performance. A vehicle with an in-line four-cylinder engine was used for the experiment, which was conducted in a lab setting. This vehicle’s eight components were gradually disengaged. The change in engine power was observed while they were disconnected. The measured values were always evaluated in terms of an automobile that had no defects and was in excellent condition. The study’s findings demonstrate that there are circumstances in which a vehicle’s usual operation is adversely affected when one or more of its electrical components malfunctions.
EN
The article presents the laboratory tests results of the influence of the diesel oil content in a mixture with rapeseed oil on the operating parameters of a diesel engine with the CommonRail fuel supply system. Fuel mixtures with a rapeseed content of 0%, 50%, 70%, 100% were used. The article presents the results of tests carried out for various configurations of the object. The measurements included tests of exhaust gases: the content of carbon monoxide, carbon dioxide, hydrocarbons, nitrogen oxides as well as specific fuel consumption and exhaust gas temperature. As a result of the research, it was noticed that the use of rapeseed oil causes a significant increase in fuel consumption and an increase in emissions. At a crankshaft speed of 2500 rpm and a torque generated by the engine crankshaft of 12 Nm, the specific fuel consumption for a 0% rapeseed content is 310 g/kWh. For the same engine operating conditions and the same rapeseed content of the fuel, the fuel consumption for 100% rapeseed content is 330 g/kWh. For the same engine operating parameters, analysis of the carbon dioxide content in the exhaust gas yields a value of 7.8x104 ppm for a rapeseed content of 0%. For the same engine operating conditions and for the oilseed rape content in the fuel is 100% 8.4x104 ppm. The mathematical models describing the effects of engine operating parameters and rapeseed oil content in the mixture on the observed values were created with the Scilab program. The degree of agreement of the determined mathematical models was checked by calculating the coefficient of determination (R2). The results are shown in 3D figures.
17
Content available Continuing a vehicle fitted with run flat tyres
EN
Modern vehicles are equipped with many systems that monitor the security of driving. An example is the tyre pressure monitoring system that shows a fault if the tyre pressure is lowered. Low tyre pressure or no pressure at all (0 kPa) means that continuing driving may lead to a dangerous situation. Prolonged driving of the vehicle at 0 kPa in the tyre ends with tyre burst, rim damage, or even loss of stability. Therefore, on the automotive market, manufacturers offer Run Flat tyres adapted to emergency driving with a pressure of 0 kPa. This article presents the results of an experimental research in the field of vehicle dynamics, continuing driving a vehicle with a loss of tyre pressure. These tests were carried out not only to confirm the data provided by tyre manufacturers and to verify the vehicle's driveability but also to analyse the effectiveness of stopping vehicles equipped with this type of tyres using, for example, police studs, especially when vehicles are used for crimes or terrorist activities.
EN
When delivering goods in the warehouses of enterprises, courier and forwarding companies, and for logistics operators, loading and unloading is usually done manually or mechanically. On the other hand, the load can first be placed on the ground next to the vehicle and then accepted in the pile, or a ramp can be used so that it can be delivered directly to the warehouse or vice versa. When there is a ramp, the loading and discharging activity is performed faster and it is much easier. When there are many vehicles serviced on ramps, it is necessary to have a free ramp available. This is often not the case when the warehouse has more ramps and a large exchange of goods. In this case, a time schedule is usually made for the reception and handling of vehicles, which is communicated to carriers and drivers so that there is no unnecessary downtime of vehicles and overloading of points with ramps. There are cases in which the established organization of work cannot be performed due to various force majeure or other reasons, such as delays at border crossings, bans on passing through certain sections, change in the working hours of warehouses, pandemic and other reasons. The vehicles then arrive at the checkpoints at a time that is different from their schedule and have to wait to be serviced. Waiting at the unloading points makes drivers nervous and they become dissatisfied with the working conditions. In this respect, a solution has been proposed based on the working hours and occupancy of the loading and discharging point and the time of arrival of the vehicles at the point, and how to receive the vehicles so that the waiting time between them is the shortest. For this purpose, a partially integer linear optimization model has been created in Matlab, which provides a valid plan with the shortest waiting times for all vehicles. Simulations have been made for different numbers of ramps and vehicles. The results show that the model is suitable for pre-creating a valid plan for the operation of the vehicle warehouse, if any, with a minimum waiting time.
EN
This article deals with the possibilities of adhesion force changes of a road vehicle. The authors present the possibilities of reducing the adhesion force of road vehicles and, at the same time, present their own system for changing the radial reaction of the vehicle wheels. This system removes the disadvantages of a commercially available SkidCar system. A representative road test is chosen in the article to determine the stability in a straight-line drive. Furthermore, the authors report the courses of characteristic parameters describing the behavior of a vehicle for driving a conventional car on a sliding surface and compared to the 50 % radial reaction of a vehicle driven with the SlideWheel on dry asphalt. It is clear from the measured runs that it is possible to change the adhesion force by changing the adhesion weight transmitted by the vehicle wheels. The use of the proposed SlideWheel system is possible for the purpose of verifying vehicle stability, while improving the driver's ability to operate the vehicle under reduced-adhesion conditions. The main goal of this paper is to design a system for reducing the adhesive force in an experimental car and perform experimental measurements.
EN
An essential part of a sustainable city is sustainable transport; however, the development of transport has led to the growing noise pollution. It is obvious that the road-traffic noise has negative health impacts on the population in the cities. These effects should be reduced to ensure the sustainability of modern cities. The main purpose of the study was to compare the changes in the noise level in the mountainous city in 2012 and 2016 compared to 1990. A hypothesis was introduced that over the past 26 years, the level and severity of noise during the day and night increased along with traffic and the number of cars. In addition, a comparison of the value of the traffic intensity of passenger cars and trucks during the daytime in the years 2012–2016 was made. Additionally, the noise generated by vehicles during the day and night was compared. On the basis of the results obtained, it can be concluded that the level of noise during the daytime over the last 26 years has clearly decreased. The main factors that reduced the noise level were the improvement of the quality of vehicle fleet, directing transit traffic to the city beltways, as well as the local use of noise barriers. However, the level of noise intensity at night increased significantly. This is due to the increase in the total number of vehicles in the city and their high speed at this time.
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