Scientific Journal of Silesian University of Technology. Series Transport

8

Authors: Leszek MINDUR, Maciej MINDUR

The excessive increase in transport intensity is one of the negative impacts on the economy. The costs borne due to transport activities are indirectly expressed by the volume of carriages (in tons) and by the scope of transport activity (in ton-kilometers). The result of social and economic activities are global product values and national incomes. This article shows the research on transport activity expressed through transport activity (in ton-kilometers) for all means of transport in total, the results of social and economic activities expressed using the gross domestic product, as well as shaping transport intensity of national economies in selected European countries. The analysis of the course of the exponential function curves, as well as polynomial curves has been carried out, and conclusions have been formulated on their bases.

10

Authors: Radka JÍROVÁ, Lubomír PEŠÍK

Vibroisolation systems of base desks for machine and testing facilities usually cannot effect efficient changing of their own frequencies according to operating conditions. Especially in the case of the automotive industry, the possibility of changing natural frequencies is very desirable. During varying operating conditions, the vibroisolation system needs to be regulated easily and quickly regarding the minimisation of dynamical forces transmitted to the ground and to ensure the stability of the testing process. This paper describes one of the options of tuning the base desk at a relatively short time and by sufficient change of own frequencies, which decides the dynamical behaviour of the whole system.

11

Authors: Elżbieta MACIOSZEK

Transport plays an important role in the economy of any country. Efficient and developed transport infrastructure of various modes of transport significantly affects the availability of transport services, and consequently, the well-being of citizens. This article presents an analysis of the volume of passengers and cargo transport using rail and road transport in Poland in 2009-2019. These analyses were carried out based on data obtained from the Central Statistical Office. All data concerns Polish entities that provide services in the field of passenger and freight transport in Poland and focuses on such information as the volume of passengers and cargo by individual means of transport, broken down into domestic and international transport. Further, the presented analyses concern the length of the available rail and road routes, tracks, the size of the rolling stock as well as the groups of transported loads.

12

Authors: Siarhei AZEMSHA, Irina KRAVCHENYA, Yuriy VOVK, Oleg LYASHUK, Iryna VOVK

Schedule optimization is a proven strategy to improve service quality for public transport networks. However, current research mostly optimizes schedule design using prior knowledge of users’ routings, ignoring the optimization of public transport schedules on duplicating stretches of route vehicles. This article presents a new alignment technique of time intervals between consecutive vehicles of different routes on duplicating stretches, considering existing public transport networks in attaining optimization of public transport schedule. Scheduling technique of route vehicles on duplicating stretches includes some steps: analysis of public transport network and determining a lot of duplicating stretches, calculation of the optimal time intervals among arrivals of route vehicles and alignment of these intervals among consecutive route vehicles on duplicating stretches, realization simulation model of urban passenger transport within the simulation modeling system of GPSS World. Furthermore, testing the optimization technique of route vehicle scheduling, analysis of the quality of adjusted schedule with route vehicles of different kinds included, and determining the optimization efficiency for duplicating stretches. The adjusting technique of urban passenger transport schedule allows to increase movement steadiness of consecutive vehicles of different routes on duplicating stretches, adjust traffic intervals for each route, shorten the traffic load on stations, reducing idle time and queue lengths of route vehicles in front of transport stops and also minimize waiting time for route vehicle by those passengers who can be transported along several routes. Improving the bus schedule on duplicating stretches in Gomel is illustrated demonstrating the technique developed. This scheduling technique can be used by carriers and transport operators to improve the quality of services provided.

13

Authors: Mulugeta GIRMA, Berhanu WOLDETENSAE

Due to its low fares, public bus transportation as a means of urban road mobility is a popular choice, particularly among city inhabitants. However, owing to its high level of crowdedness, it poses a greater risk of security and safety, particularly during peak hours. Moreover, passengers have continued to voice their dissatisfaction about the services offered, as well as the criminality that occurs in the station and on the bus. The problem is exacerbated in developing countries due to increased travel demand and a lack of appropriate and integrated solutions. Consequently, the purpose of this study is to evaluate commuters' perceptions of their concerns about using public bus transportation in the city, with an emphasis on security and safety in bus operations. A questionnaire survey was used to obtain data from 500 users in the city for the study. Using the SPSS software, the data was analyzed. To find out what they think, a descriptive analysis was used. Overcrowding of buses, personal insecurity, and infrequent bus service are the three biggest concerns in using public bus transportation in the city, according to the results. Furthermore, most of the respondents were concerned about crime; specifically, pickpockets, inappropriate touching, and disrespectful language of drivers and conductors are the three top types of crime that concern passengers who use public bus transportation in the city. Additionally, most people felt more insecure while riding the bus and getting on/off the bus, particularly in the evening and between 9:00 and 12:00 p.m. local time. Thus, it is advised that the Addis Ababa City Transport Authority, the Public Bus Transport Enterprise, and other interested parties place a strong emphasis on security and safety when providing public transportation in the city. Furthermore, it is critical to perform regular victim surveys of passengers (as well as operators) to establish whether they have been criminally victimized on the bus system and by what type of crime. Equally important, regularly assess the likely usefulness of new crime prevention measures for reducing bus-related offenses and prepare an annual bus crime reduction strategy.

14

Authors: Zbigniew STANIK, Andrzej KUBIK, Damian HADRYŚ, Csaba CSISZÁR

This article presents two methods of testing bearing hubs, which may supplement the existing subjective and unreliable methods of diagnostics of rolling bearings used in wheel bearing hubs of motor vehicles and other means of road transport. One of the most important elements responsible for the safety of a vehicle is the bearing hub. Regular monitoring of the technical condition of bearings should become an obligation at vehicle inspection stations when carrying out a technical inspection of a vehicle, authorising it to travel on public roads. This article presents the results of vehicle tests with signs of damage to rolling bearings, using two test stands: one on which the dynamic balancer acted as a device for accelerating the wheel, and the other, which was designed as a test dedicated to automotive rolling bearings, where a dynamic weighbridge was used as the wheel drive, made it impossible to test the wheel at lower rotational speeds. The newly designed and manufactured bearing testing device eliminates the disadvantages of the previous stand, and additionally, enables the measurement of a fully loaded bearing hub, which enables the simulation of real operating conditions on the bearing hub.

15

Authors: Monika BLIŠŤANOVÁ, Michaela KEŠEĽOVÁ, Ľubomíra BRŮNOVÁ

Safety is generally characterised as the state of being “safe”, the condition of being protected from harm or other non-desirable consequences. One effective way of achieving it is to implement a safety management system (SMS). SMS should be seen as an aggregate strategic aspect of standard business management, understanding its high priority to safety. This article describes and illustrates SMS in aviation, focusing on the similarities and differences in the system approaches adopted by selected Civil Aviation Authorities (CAAs) with the primary focus on the safety level. The main goal is to provide a structural comparison of the system framework within individual CAAs and its explanation in safety-related documents. This article also dealt with the chosen safety approach (reactive, proactive and predictive) and safety performance indicators (SPIs), forming a quality and effective safety system that maintains an acceptable safety level. Finally, this article is mainly based on datasets publicly available through the International Civil Aviation Organisation, Transport Canada, Civil Aviation Safety Authority Australia, Federal Aviation Administration, UK Civil Aviation Authority, Civil Aviation Administration of China and Civil Aviation Authority of New Zealand websites and documentation related to safety.

16

Authors: Piotr GORZELANCZYK, Ida POLAK

The main purpose of this article is to make a forecast of the load on the night lines using the Municipal Transport Company in Piła (MTC) as a case study. This article characterizes the concept of urban logistics and mobility, and then proposed a mobility model that considers the preferences of residents when choosing a means of transport. Finally, it ends with a survey and the appropriate conclusions drawn.

17

Authors: Vladimir SHPACHUK, Aleksandr CHUPRYNIN, Tatiana SUPRUN, Andriy KOVALENKO

Mechanical models of a transport system “carriage - track” while crossing a joint irregularity are proposed. An investigation was conducted on the peculiarities of static, shock and dynamic interaction between the four-axle car and the track, considering tram wheelsets motion features over joint irregularity. A method to solve the equations of a mathematical model of static, shock and dynamic interaction is developed. Numerical analysis is used to determine deflections of the facing rail under the first sleeper for each phase of motion depending on motion phases, and car load and speed.

8

Authors: Igor Alex VAKULENKO, Sergey PLITCHENKO, Bulent KURT, Hangardas ASKEROV, Svetlana PROYDAK, Ahmet Emrah ERDOGDU

During a study of the combustion process of a direct polarity electric arc, a directly proportional dependence of the electric current value on the degree of cold plastic deformation of carbon steel used as an electrode was found. To calculate the value of the electric current during arc burning, in the indicated ratio, it was proposed to replace the surface tension force of the liquid metal with the surface tension of ferrite of plastically deformed carbon steel. Calculation of the ferrite’s surface tension value on the deformation degree of the steel under study through the size of the coherent scattering regions was used to explain the observed dependence of the electric current during arc burning. From the analysis of the considered correlation ratios, it was found that with an increase in the cold deformation degree, the refinement of the coherent scattering regions results in the ferrite’s surface tension increase and consequently, to an increase in the electric current during arc burning. Comparative analysis of the obtained results of calculating the value of electric current during arc burning through the surface tension of ferrite of cold-deformed carbon steel showed a fairly good coincidence with experimental data. The differences did not exceed 9%.

9

Authors: Janak TRIVEDI, Mandalapu Sarada DEVI, Dave DHARA

We present vehicle detection classification using the Convolution Neural Network (CNN) of the deep learning approach. The automatic vehicle classification for traffic surveillance video systems is challenging for the Intelligent Transportation System (ITS) to build a smart city. In this article, three different vehicles: bike, car and truck classification are considered for around 3,000 bikes, 6,000 cars, and 2,000 images of trucks. CNN can automatically absorb and extract different vehicle dataset’s different features without a manual selection of features. The accuracy of CNN is measured in terms of the confidence values of the detected object. The highest confidence value is about 0.99 in the case of the bike category vehicle classification. The automatic vehicle classification supports building an electronic toll collection system and identifying emergency vehicles in the traffic.

10

Authors: Elżbieta MACIOSZEK

Nowadays, air transport is treated as a dynamically developing sector of the world economy. The technological solutions used in this kind of transport are highly advanced; thus, generate high costs, ranging from research through production to the implementation phase. Due to its technological advancement, air transport has several significant advantages over other kinds of transport. This paper presents the characteristics of selected airports in Poland together with statistical data characterising the functioning of the airports. In addition, the plans in recent years regarding the development of air transport infrastructure in Poland were summarised.

11

Authors: Piotr GORZELANCZYK, Bartlomiej SEWERYN

The rapid increase in the number of vehicles in cities and the intensity of their movement necessitates the use of appropriate transport management solutions. Various telematics techniques are used in logistics transport management in cities, which are the basis for the functioning of telematics systems. This article analyses selected telematics techniques used in logistics transport management in cities and presents the developed concept of changes in logistics transport management in the city of Piła, including the use of appropriate telematics techniques. The existing telematics system in the city of Piła and the proposed solutions were subjected to appropriate examination. This study aimed to verify the quality of the current state of the system and learn opinions on the proposed solutions that could be implemented in Piła, considering the effects that could be achieved as a result of improving the existing system. The survey method was used to obtain relevant information. The questionnaire developed, containing the elements assumed in this study, was addressed to respondents residing in Piła and its environs. The survey was conducted in December 2020 and January 2021.

12

Authors: Ali Payıdar AKGÜNGÖR, Elif Zahide MERCAN

Intersections, for vehicles coming from different directions, are conflict points in road networks. When a driver approaching a signalised intersection encounters the yellow light, he/she is in a dilemma either to safely stop or to pass through the intersection during clearance time. The decision to stop or to pass may change depending on some factors such as duration of yellow light, deceleration and acceleration rate, width of intersection, speed and length of vehicle, etc. This study aims to put forth the effects of some related factors affecting the length of the Type I dilemma zone. To perform this study, five factors including vehicle speed, maximum deceleration rate, perception-reaction time, clearance time, the total intersection width-vehicle length were considered and a total of 648 different traffic cases were investigated. The study results showed that the Type I dilemma zone length increased with the increase of speed, total intersection width-vehicle length and perception-reaction time, but decreased with the increase of clearance time and deceleration rate.

12

Authors: Mohammad Mehdi KHABIRI, Pooya AFKHAMY MEYBODI, Ali Mohammad MONTAZERI

Skip resistance of asphalt is an important parameter that can influence the safety of drivers on roads. Although there is a linear relationship between slipping on road surfaces and accidents, the impacts of pollutants for decreasing friction of roads is clear to researchers. Moisture and temperature influence friction and safety. In this research in SMA samples, three different gradations with the maximum nominal sizes of 19, 12.5 and 9.5, based on international standards were used. For polluting the surface, five materials that are found on roads were used, including fine-grained soil, sand, oil, soot and rubber powder. To measure the skip resistance, the British pendulum tester was used and for analysing macro-texture, the sand patch method was used. The results of this research showed that by increasing the maximum nominal size of aggregates, the depth of macro-texture in surfaces are grown and this is due to the decrease of fine aggregates in larger gradations. Because of the higher flexibility of pure bitumen, the applied compression pressure on rigid aggregates can cause indentations in the substrate and result in declining the roughness height of aggregates in the mixed surface. This leads to declining the hysteresis part of friction by increasing temperature.

13

Authors: Tomasz KĄDZIOŁKA, Kazimierz OPOKA

Steering systems are one of the most important components of a car and have a direct impact on safety and driving comfort. Therefore, high reliability is required of them. One of the methods of object reliability estimation may be the grey system theory. This method can be used not only to calculate the number of failures, but also to calculate the wear of mating parts, and the vibrations of engines and rolling elements. This work presents the use of the grey system theory for the examination of motor vehicle steering system reliability. The forecast number of failures was calculated for the various components of the steering system and the grey system accuracy was assessed. This is aimed at finding out how useful this theory is for forecasting the number of steering system failures.

15

Authors: Jacek CABAN

Transport has a great impact on human activities but contributes to many negative phenomena occurring in road traffic, for example, road traffic accidents, emission of toxic exhaust fumes into the atmosphere and a high share of cars in road traffic. For the above reasons, many initiatives have been taken in the field of road traffic management and urban logistics. Based on a literature review, it was found that the problem of the phenomenon of traffic congestion in urban areas remains an ongoing issue. In the first part of this article, the theoretical issues of traffic flow and congestion formation in the city road networks were presented. While the second part outlines the situation of transport congestion in 10 Polish cities based on the worldwide TomTom Traffic Index in the years 2008-2018. This study is a brief analysis of the trends relating to transport congestion based on the TomTom Traffic Index in these cities.

19

Authors: Obioma R. NWAOGBE, Somtochukwu P. ODIOBULU, Victor OMOKE

This study assesses the operational safety and security of a category one airport in Nigeria, using the Nnamdi Azikiwe International Airport, Abuja (NAIA) as the case study airport. Data were sourced using structured questionnaire and oral interviews. A total of 180 questionnaires were administered and 165 questionnaires were retrieved, amounting to a 91.7% rate of response. The structured questionnaire used aimed at identifying various safety and security parameters in the study area. This study examined the trend of the effectiveness of safety and security variable in airport operations, safety and employee’s attitude towards safety risk management using the Multicriteria Decision Analysis model to achieve this objective. The results show the weighty level, satisfaction index and effective index of the safety and security parameters used in the analysis with their score and effective index graph. Recommendation on how to improve the airport safety operations were made following policy implication on how to improve the safety management system of the airport.

8

Authors: Michal PUŠKÁR, Melichar KOPAS, Marieta ŠOLTÉSOVÁ, Matúš LAVČÁK

The innovative system, which was developed for analysis and correction of motor management, is determined for the solution of practical problems concerning the operation of the piston combustion engines. Programming of the ignition curves and fuel maps without relevant feedback, namely, without information obtained from the engine operation, increases the risk of detonation combustion, which can destroy the combustion engine. However, the main application area of this system is the development of an algorithm, which is specified for control of the combustion process based on the HCCI technology (Homogenous Charge Compression Ignition). Nowadays, the functional principle of the HCCI engine is one of the most effective possibilities on how to reach higher operational efficiency of the gasoline engine, that is, closer to the efficiency level of the diesel driving units.

9

Authors: Blerina BEQAJ, Entela ÇOBANI

Groundwater quality study was conducted in the Drini basin situated in the northern part of the Albanian territory. The objective of this study was to identify the quality of groundwater in four different well-defined monitoring sites. Groundwater is vital for the population and is considered to be subject to continuous exploitation with high growth intensity, and permanent risk of pollution from natural and human activities. Contamination of groundwater occurs when synthetic products such as gasoline, oil, road salts and chemicals get into the groundwater and return it unsafe and unfit for human use. Groundwater monitoring was carried out according to a network, which aimed to include mainly the most intensive areas of exploitation and distribution in the aquifer. Samples were collected in two different months of June and October in four monitoring drilling sites and were analysed for those key indicators defined by the rules and procedures for the drafting and implementation of the national programme of environmental monitoring in Albania. The study results reveal that geological formation, human activities as well as environmental conditions affect groundwater quality. Complete chemical analysis revealed that the groundwater in this area results in medium hardness, has good physico-chemical properties, local pollution is encountered, and there is no massive pollution of the basin. They are waters with low mineralisation. Further, they are neutral waters, which meet the allowed norm for drinking water. The pollution displayed is occasional, as the presence of NH4+ and NO2- are isolated cases, manifested mainly by the non-application of areas of strictness and sanitary protection around the drill and the small cover of the subaxillary layer. The analysis performed for microelements shows that the content of some heavy metals is below the maximum allowed amount; this demands serious future attention to the density of the network and the monitoring frequency in this basin. The risk of pollution in the Drini basin is high due to the small protective cover, especially in the source of Dobrac. Intensive exploitation can lead to the mixing of fresh water with water with high mineralisation. The concentration of Cu, Pb, Zn, Cr, Cd, Na+, K+ and Cl− in the water samples known as the major pollutants from the urban transport sector, has shown that the values are within the water quality standard. The low concentration of these pollutants was due to the distance of the drilling sites from the roads in these areas.

10

Authors: Andrzej KUBIK, Zbigniew STANIK, Damian HADRYŚ, Csaba CSISZÁR

This article presents an innovative method of diagnostics of rolling bearings used in the bearing nodes of motor vehicles, with the use of a prototype specialist stand. The tests were carried out based on a developed research plan, which included the impact of damage to the bearing and tyre of the vehicle, as well as the vehicle speed. Vibration accelerations were recorded in three measurement axes. Signal spectra were created based on the time courses of the vibration signals and were further analysed. The presented method is aimed at detecting excessive wear of rolling bearings in wheels from its early period.

10

Authors: Peter B. OLADEJI, Hafeez Idowu AGBABIAKA

This study examined the effectiveness of para-transit transport activities by identifying the socioeconomic characteristics of both the passengers and drivers of public transport and the factors confronting their operation. It utilised primary and secondary data. A purposive sampling technique was employed which entailed the identification of all the motor parks, the selection of buses, minibuses and cars at the motor parks, major bus stops and conducting a survey using a structured questionnaire cum interview. Questionnaires were administered to 354 respondents to obtain information about their socioeconomic, trip characteristics and the unconventional public transport operations, of which a total of 312 questionnaires were duly completed and returned. Data collected were analysed using simple descriptive techniques and correlation analysis. The results showed that the majority of the passengers (61.4%) were within the 21 – 30 years age bracket while 43.7% of the drivers were within the 31-40 years age bracket, the patrons and the operators of the public transport are predominantly low-income earners as large proportion of the passengers (42.1%) earned below ₦10,000 per month while 46.9% of the drivers earned between ₦10,001 and ₦20,000 per month. The results of the correlation analysis indicated both the drivers’ and passengers’ perspectives, factors such as public transport conditions, road quality and drainage system are highly correlated between their paired variables. Hence, effort should be made by the government and public transport operators to improve the transport infrastructural facilities in the study area.

10

Authors: Ondrej STOPKA, Maria STOPKOVA, Iwona RYBICKA, Patrik GROSS, Karel JEŘÁBEK

This research outlines a research study wherein an implementation of the activity-based costing (ABC) approach for cost management in a railway transport enterprise is addressed. ABC is an efficient technique for enhancing the quality of provided services and process complexity of certain railway companies, executing its activities at a regional or international scale. It is one of the new costing approaches that eliminate the inaccuracies and deficiencies of the traditional costing system. Compared to other costing techniques, considerable change lies especially in the way of assigning indirect cost units to activities based on actual causations, and subsequently, assigning activities to the very cost items by the intensity of their consumption. Furthermore, this approach allows decision-makers to identify specific cost item in terms of determining ways of how they can be managed. The main objective of this work is to elaborate a particular study with a draft application of the ABC method encompassing a description of procedure steps, along with relevant quantifications, as well as summarising the results obtained.

12

Authors: Anjali TARAR, Deotima MUKHERJEE, Kalaga Ramachandra RAO

The purpose of this study is to analyse the accuracy of the static schedule of bus transit network in Delhi using real-time data available from Delhi’s Open Transit Data (OTD) platform. To access and organise the data, an algorithm that can convert real-time data into a General Transit Feed Specification (GTFS) format, needs to be designed. Further, this study intends to develop a methodology, which can convert raw data of bus locations into link travel times, which consequently, helps in identifying problematic links. As researchers continue to make use of the data available via GTFS, they may well be aware of the fact that such data may differ systematically from actual transit operations. Continuous improvement of the accuracy of the GTFS static file would benefit its users.

13

Authors: Piotr SOCZÓWKA, Marcin Jacek KŁOS, Renata ŻOCHOWSKA, Aleksander SOBOTA

Sustainable mobility is a priority for transport systems in urban areas. Contemporary planning of transport systems assumes an increase in the role of public transport in everyday trips. To increase the share of trips using public transport, it is essential to improve the accessibility of public transport stops. The accessibility of such stops depends primarily on the distance between the trip origin and the stop. Many factors influence the distance that passengers are willing to travel. This paper discusses the relationship between the access time to the bus stop and travel time. To study such a relationship, various statistical methods may be applied. This paper presents the results of the analysis performed based on the data on trips made by inhabitants of Bielsko-Biała, gathered during the building of its transport model.

14

Authors: Kamil KRASUSKI, Mieczysław BAKUŁA

This article presents and describes the operational capabilities of an onboard GNSS receiver to determine the reliability of the in-flight navigation parameters. An analysis was made of the operation reliability of an autonomous single-frequency Thales Mobile Mapper receiver in air navigation as compared to the technical operation of a dual-frequency Topcon HiperPro receiver. To this end, this work contains a comparison of the aircraft flight navigation parameters based on readings obtained from the Thales Mobile Mapper and Topcon HiperPro receivers. In particular, the comparison concerned the reliability of coordinate determination and flight speed parameters of an aircraft. The research experiment was conducted using a Cessna 172 aircraft, a property of the Military University of Aviation in Dęblin, Poland. Technical operation of the GNSS satellite receivers was tested in the flights of the Cessna 172 aircraft around the EPDE military airport in Dęblin. Based on the results obtained from the tests, it was found that the operational reliability of the Thales Mobile Mapper in the operational phase of the in-flight test ranged from -3.8 to +6.9 m in the XYZ geocentric frame and from -2.2 to +8.1 m in the BLh ellipsoidal frame, respectively. On the other hand, the accuracy of the Cessna 172 aircraft positioning when using the Thales Mobile Mapper receiver was higher than 1.7 m in the XYZ geocentric frame and higher than 2 m in the BLh ellipsoidal frame, respectively. Furthermore, the reliability of the Cessna 172 flight speed determination was from -3.4 to +2.4 m/s.

18

Authors: Piotr GORZELANCZYK, Maja WOJTASIK

This article aims to examine the emission of pollutants utilising transport in different points of the city in question at two different intervals, then show whether the means of transport negatively affects the city through pollution. The study of air pollutant emissions from transport sources is a key aspect towards solving problems related to environmental pollution. A study on the measurements of selected PM10 and PM2.5 pollutants to be able to determine the quality of air from transport sources in Pila at different times of the year and with appropriate assumptions regarding the appropriate distance by the road is included in this article. This study analysed data on air pollutants and compared it with the results of the Chief Inspectorate for Environmental Protection. This made it possible to propose solutions for the development of the air condition in Pila.

8

Authors: Elżbieta MACIOSZEK

During the transportation of goods, damage and destruction of the transported cargo constitute a very large part of the damage. The most common direct cause of damage is an improper arrangement and securing of the transported load. An improperly secured load may pose a threat to the transporters and bystanders. Incorrectly secured loads can fall from the vehicle, obstruct movement, and cause injury or death. In addition, improperly secured loads can cause injury or death in heavy braking or a collision. The way the load is distributed and secured on the vehicle can negatively affect driving behaviour, making it difficult to control the vehicle. This article presents the conditions related to the transport of loads in road transport, describes both the forces that act on the load during the journey of a vehicle and the most important techniques for securing loads in road transport.

9

Authors: Nodira SOATOVA

This article presents the results of the analysis of experimental data on testing of reinforced concrete elements for multiple-repeated loads and field tests of operated span structures. This article proposes dependencies on the definition of deflections during the operation period. Based on the processing of the available experimental data, dependences are proposed for determining deflections under multiple repeated loads, and on this basis, dependences are obtained for predicting the residual life of span elements. The initial data for the calculations are the data on the accumulated residual deflections determined in the process of technical diagnostics.

10

Authors: Silvia MALÁKOVÁ

In practice, gear units whose transmission number is not constant during one revolution are used. Such gears include the proposed elliptical transmission. Its application can be (missing a word?) and the automotive industry. The gears set consists of a pair of identical elliptical gears. The transmission ratio of the designed elliptical gear is not constant. The basic kinematic characteristics of this transmission are described in this work. The deformation in contact point of non - circular gears is determined by the finite element method in this paper. The results are compared with the deformation of the teeth of the spur gears.

11

Authors: Ján DIŽO, Miroslav BLATNICKÝ, Paweł DROŹDZIEL, Stanislav SEMENOV, Evgeny MIKHAILOV, Jakub KURTULÍK

The lorry frame is the main carrying part of a lorry, composed of several components. These components are connected by joints into one structural unit and it forms the lorry chassis. The contribution of this article is focused on the strength analyses of a backbone frame, which is used on an off-road lorry chassis. Strength analyses are carried out utilising the finite element method. This article presents a created three-dimensional model of the frame and definition of boundary conditions (loads, the definition of degrees of freedom) needed for simulation computations. Results of the numerical calculations are the main parts of this article. Attention is mainly centred on the distribution of stresses of the frame under defined loads and its deformations.

12

Authors: Mikhail ZHILEVICH, Sergey ERMILOV, Denis KAPSKI, Yuriy VOVK, Oleg LYASHUK, Iryna VOVK

The design dimensions of the executive hydraulic cylinders of the brake system of heavy-duty mining dump trucks cause high fluid flow during the braking process. Therefore, dimensions of the anti-blocking system modulator spool pair require unique electromagnets or hydraulic amplifiers to control. These solutions do not allow the required modulator performance. Thus, a modulator scheme with a division of the flow of fluid from the source to the brake cylinders was developed. This scheme allows during emergency braking passing, an additional amount of fluid to cylinders through the valve, installed parallel to the main valve upon pressure increase phase and controlled by the pressure difference. The task is to develop a method for calculating the main structural dimensions of a modulator. The calculation of the valve of the second cascade, installed in parallel to the main stage, is carried out for the emergency braking mode with the maximum flow rate to ensure the required performance of the braking system. The balance of fluid flows equations is compiled at the key points. The flow rate of the fluid through each of the valves is determined by the Torricelli formula, and the pressure difference across the valves is assuned equal. The obtained relations allows building a family of Q-p curves, which can be used to select the diameter and stroke of the additional valve depending on the flow rate in the brake system.

13

Authors: Ladislav ILLES, Martin JURKOVIC, Tomas KALINA, Piotr GORZELANCZYK, Vladimir LUPTAK

Increasing transport volumes on Europe's inland waterways is a major reason for improving the quality and reliability of internationally important waterways. Continued navigation restrictions due to restricted draft (draught) led to the search for new design solutions. Such solutions enable navigation even under critical navigation conditions. Restricted draft is one of the most important limitations that hinder navigation, especially in the summer. The main objective of the construction of an inland vessel is to obtain a shape that will achieve optimum performance with as little resistance as possible. A shape that will be able to navigate at a limited depth. Presently, there is no clearly defined methodology as a procedure for optimising the hull. When solving theoretical problems of shipbuilding character and ship calculations, it is necessary to consider the basic theory of the ship with special regard to the latest methodological procedures of related scientific disciplines. This paper presents a methodology that considers all the basic aspects of optimisation tasks in ship design and construction.

13

Authors: Dahlen SIQUEIRA SILVA, Csaba CSISZÁR, Dávid FÖLDES

Discussions on how urban space would be transformed by the use of autonomous vehicles (AVs) are scarce. This study identifies the impacts caused by the shared use of AVs on urban parking and urban space management. An estimation method was formulated considering the reduction in parking demand, the possible alteration in vehicle ownership, and the reallocation of urban space. A case study was performed in a 673,220 m2 area through scenarios created by using real data of parking spaces and the results of previous studies. Results showed that parking spaces can be saved with the use of shared AVs, which would allow the reallocation of urban space to new uses (for example, implementation of around 12,000 bike-sharing docking spots, 10 km bike lanes, 7 km additional traffic lane or 140 ‘parklets’). The results contribute to revealing the positive impacts of AVs.

16

Authors: Greg WHEATLEY, Samuel POPOOLA

Investigation on a designed and modified standard automatic transmission for a 2017 Yamaha Grizzly All-Terrain Vehicle was carried out to allow it to be controlled remotely and autonomously while maintaining its ability to be manually operated. The vehicle is a part of a project named AutoWeed. This project aims at developing a vehicle which can be used in the Australian outback to control and eradicate weeds. Preliminary tests were conducted on the vehicle to determine the performance parameters required to replace the movement supplied by the operator. Several devices used to achieve this motion were explored. It was concluded that the Motion Dynamics HB-DJ806 - LALI10010 electromechanical linear actuator be used as a proof of concept device for this application. This device is capable of exerting 200 N at 35 mm/seconds. It has a stroke length of 50 mm and was powered by a 12V DC motor, which drew 3 amps at maximum load. Through testing, it was found that the selected actuator did not have enough stroke length to cycle through the five gears on the ATV. This error was rectified allowing the system to function as intended. To achieve a reliable design, however, the Linak LA14 actuator was purchased as a final design as it was stronger, faster and had feedback capabilities. Before procurement, the new actuator was digitally modelled using SolidWorks 2017 and 3D printed to confirm the mounting position and method. An ANSYS FEA was conducted on all the custom-made components including the actuator bracket and mounting plate to ensure reliability. The bracket model was manufactured using 3D printing from ABS. It was recommended that for reliability, the bracket should be constructed from a stronger material such as aluminium. The results gained from testing proved that the autonomous transmission system implemented was reliable and repeatable. This was justified as the system achieved a 100% success rate when cycling through gears.

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Authors: Olorunfemi Ayodeji OLOJEDE

Over two-thirds of greenhouse gases (GHG) emissions that contribute to climate change emanate from transport. This could double by 2050. With per capita emissions nearly twice the global average, South Africa ranks 13th globally on GHG emissions with road transport, directly and indirectly, accounting for 91.2% of total transport GHG emissions. It has been projected that by 2100, up to 100% increase in the country’s average temperature above the 20th century average rise. This has far-reaching implications, even for the transport sector. To decarbonise its transport sector, South Africa has committed to reducing its GHG emissions by 34% by 2020 and 42% by 2025, respectively, through pointed strategies and policies. However, efficient implementation of proposed measures and sufficient funding remain daunting challenges. Thus, this paper contends that adequate attention has not been paid to active transport in the country’s transport decarbonisation policy implementation despite its inclusion in policy statements. It then asserts that active transport is indispensable to South Africa’s achievement of its transport decarbonisation goals, especially when steps taken hitherto seem ineffective. Consequently, the right attitudes, regulatory instruments, and policy initiatives towards the promotion of active transport are recommended.