This work aims to solve one of the essential problems in railway transport – control over the position of moving units within the race. A method of constant monitoring of the track circuit with a determination of the coordinate of the train shunt placement in the shunt mode of working is proposed to solve this problem. Since the model includes the primary parameters of the track circuit, which may change their values over time, it is suggested to determine them in another (normal) working mode of the track circuit. Therefore, according to the proposed model, the secondary and primary parameters of the track circuit are first determined in the track circuit's normal work mode. Next, already in the shunt mode of its work, the obtained parameters are used to determine the coordinates of the moving unit. According to this method, firstly, the work mode of the track circuit is determined, which consists in determining the state by its input impedance. This step is performed in two stages. In the first stage, based on the state of the track relay, the fact that the track circuit doesn't work in normal mode is verified. In the second stage, the shunt mode is separated from the control mode by the value of the track circuit input impedance. In the shunt mode of the track circuit operation, the coordinate and, if necessary, the speed and acceleration of the moving unit located within the given track circuit are determined. In the normal mode of the track circuit line operation, the values of its secondary parameters are specified based on the measured values of current, voltage, and phase shift between them. This operation is performed to increase the precision of the speed and acceleration determination by solving an inverse problem. In the control mode of the track circuit operation, it is possible to determine the coordinates of damage. This method does not require a significant volume of calculations. It makes it possible to determine the secondary parameters of the track circuit and through them, the resistance of its insulation. Using this method makes it possible to determine the distance and, if necessary, the speed and acceleration of a moving unit within the track circuit. The resulting parameters can be used for positioning moving rolling stock on runs between stations. The application of this method can also be useful in sections of the railway crossings approach to implement a fixed warning time. In addition, thanks to the use of the outlined model, in the control mode of the track circuit operation, is possible to determine the damage coordinate. It will make it possible to reduce the time spent on damage detection and elimination.
{"title":"Method of determination of the railway rolling stock coordinates within the track circuit","authors":"O. Voznyak, S. Buriak","doi":"10.23939/tt2023.01.038","DOIUrl":"https://doi.org/10.23939/tt2023.01.038","url":null,"abstract":"This work aims to solve one of the essential problems in railway transport – control over the position of moving units within the race. A method of constant monitoring of the track circuit with a determination of the coordinate of the train shunt placement in the shunt mode of working is proposed to solve this problem. Since the model includes the primary parameters of the track circuit, which may change their values over time, it is suggested to determine them in another (normal) working mode of the track circuit. Therefore, according to the proposed model, the secondary and primary parameters of the track circuit are first determined in the track circuit's normal work mode. Next, already in the shunt mode of its work, the obtained parameters are used to determine the coordinates of the moving unit. According to this method, firstly, the work mode of the track circuit is determined, which consists in determining the state by its input impedance. This step is performed in two stages. In the first stage, based on the state of the track relay, the fact that the track circuit doesn't work in normal mode is verified. In the second stage, the shunt mode is separated from the control mode by the value of the track circuit input impedance. In the shunt mode of the track circuit operation, the coordinate and, if necessary, the speed and acceleration of the moving unit located within the given track circuit are determined. In the normal mode of the track circuit line operation, the values of its secondary parameters are specified based on the measured values of current, voltage, and phase shift between them. This operation is performed to increase the precision of the speed and acceleration determination by solving an inverse problem. In the control mode of the track circuit operation, it is possible to determine the coordinates of damage. This method does not require a significant volume of calculations. It makes it possible to determine the secondary parameters of the track circuit and through them, the resistance of its insulation. Using this method makes it possible to determine the distance and, if necessary, the speed and acceleration of a moving unit within the track circuit. The resulting parameters can be used for positioning moving rolling stock on runs between stations. The application of this method can also be useful in sections of the railway crossings approach to implement a fixed warning time. In addition, thanks to the use of the outlined model, in the control mode of the track circuit operation, is possible to determine the damage coordinate. It will make it possible to reduce the time spent on damage detection and elimination.","PeriodicalId":343801,"journal":{"name":"Transport technologies","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121955154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The features of the functioning of the on-board information systems of a car are considered. Threats to their security are analyzed, and methods for ensuring information security and functional security of on-board information systems are proposed. The design of road networks in the organization of road traffic is one of the factors in ensuring the functional security of modern intelligent transport systems, that is, compliance with such information security attributes as data confidentiality, integrity, availability, authenticity and novelty of data. The security of on-board vehicle information systems is a critical issue in the modern world, as more and more vehicles are equipped with electronic systems that may be vulnerable to cyber attacks. One of the main challenges of protecting on-board information systems is the wide range of devices and technologies used in modern vehicles. Different systems may have different security requirements and vulnerabilities. They may interact with each other in a complex way. Another challenge is that many of these systems were not designed originally with security in mind. They may lack basic security features such as encryption and authentication and use outdated software and protocols that are vulnerable to known attacks. The main types of attacks and threats to the elements of the transportation system that interact with the VANET were identified to analyze the information security of vehicle in-vehicle systems. Based on the theory of fuzzy sets under conditions of uncertainty and using the Fuzzy Logic Toolbox in the integrated Matlab environment, the level of information security of the OBU-VANET system was modeled. The obtained results allowed us to formulate the degree of information security of vehicle operation elements against unauthorized access to data. The results of the study showed that technical communication systems have the highest security level (> 0.7), and vehicles become the most vulnerable in public places.
{"title":"Analysis of the security of on-board information systems in vehicles","authors":"G. Weigang, Kateryna Komar","doi":"10.23939/tt2023.01.062","DOIUrl":"https://doi.org/10.23939/tt2023.01.062","url":null,"abstract":"The features of the functioning of the on-board information systems of a car are considered. Threats to their security are analyzed, and methods for ensuring information security and functional security of on-board information systems are proposed. The design of road networks in the organization of road traffic is one of the factors in ensuring the functional security of modern intelligent transport systems, that is, compliance with such information security attributes as data confidentiality, integrity, availability, authenticity and novelty of data. The security of on-board vehicle information systems is a critical issue in the modern world, as more and more vehicles are equipped with electronic systems that may be vulnerable to cyber attacks. One of the main challenges of protecting on-board information systems is the wide range of devices and technologies used in modern vehicles. Different systems may have different security requirements and vulnerabilities. They may interact with each other in a complex way. Another challenge is that many of these systems were not designed originally with security in mind. They may lack basic security features such as encryption and authentication and use outdated software and protocols that are vulnerable to known attacks. The main types of attacks and threats to the elements of the transportation system that interact with the VANET were identified to analyze the information security of vehicle in-vehicle systems. Based on the theory of fuzzy sets under conditions of uncertainty and using the Fuzzy Logic Toolbox in the integrated Matlab environment, the level of information security of the OBU-VANET system was modeled. The obtained results allowed us to formulate the degree of information security of vehicle operation elements against unauthorized access to data. The results of the study showed that technical communication systems have the highest security level (> 0.7), and vehicles become the most vulnerable in public places.","PeriodicalId":343801,"journal":{"name":"Transport technologies","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122462208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article discusses the challenges facing public transport in Ukraine in terms of reducing fuel consumption and emissions. The absence or insufficient development of means and methods for monitoring driver behaviour, as well as high staff turnover, create significant difficulties in controlling drivers and vehicles. A conducted study in Lutsk, the administrative center of the Volyn region, analyzed the driving behavior of passenger buses in the city. Results showed that typical driving modes include idling (40%), acceleration (18%), driving at a constant speed (29%), and braking (13%). The study also revealed average accelerations and decelerations, and these results do not meet the requirements of ecological driving. The correlation between driver behavior and these dynamic acceleration and braking characteristics has been established. Possible causes for this phenomenon are discussed in the study. The article proposes the introduction of modern solutions to solve these problems. These solutions are Eco-Driving Assistance Systems (EDAS) or integrated systems, such as FleetControl from TRIONA, which can help learning operating conditions and reduce fuel consumption and emissions. These programmes can also serve as effective monitoring tools for individual drivers and transport companies. This paper describes these applications and reviews the research related to their use and development. In addition, the article highlights the importance of training drivers in eco-driving as a cost-effective method of improving fuel efficiency in transport companies. The paper concludes by emphasising the need for further research to fully understand the complexities of public transport in Ukraine and the potential benefits of introducing innovative technologies for a more sustainable and efficient future for the industry.
{"title":"The need for eco-driving technologies in urban public transport","authors":"Ivan Slatov, I. Murovanyi","doi":"10.23939/tt2023.01.073","DOIUrl":"https://doi.org/10.23939/tt2023.01.073","url":null,"abstract":"This article discusses the challenges facing public transport in Ukraine in terms of reducing fuel consumption and emissions. The absence or insufficient development of means and methods for monitoring driver behaviour, as well as high staff turnover, create significant difficulties in controlling drivers and vehicles. A conducted study in Lutsk, the administrative center of the Volyn region, analyzed the driving behavior of passenger buses in the city. Results showed that typical driving modes include idling (40%), acceleration (18%), driving at a constant speed (29%), and braking (13%). The study also revealed average accelerations and decelerations, and these results do not meet the requirements of ecological driving. The correlation between driver behavior and these dynamic acceleration and braking characteristics has been established. Possible causes for this phenomenon are discussed in the study. The article proposes the introduction of modern solutions to solve these problems. These solutions are Eco-Driving Assistance Systems (EDAS) or integrated systems, such as FleetControl from TRIONA, which can help learning operating conditions and reduce fuel consumption and emissions. These programmes can also serve as effective monitoring tools for individual drivers and transport companies. This paper describes these applications and reviews the research related to their use and development. In addition, the article highlights the importance of training drivers in eco-driving as a cost-effective method of improving fuel efficiency in transport companies. The paper concludes by emphasising the need for further research to fully understand the complexities of public transport in Ukraine and the potential benefits of introducing innovative technologies for a more sustainable and efficient future for the industry.","PeriodicalId":343801,"journal":{"name":"Transport technologies","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125553417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Passenger transportation by rail is an important component of ensuring cross-border cooperation between our country and neighboring EU countries. Transport transformations are being carried out on both sides of the border, and directives are being developed and implemented to establish uniform rules and standards for the successful operation of transport and passenger movement. At the same time, the organization of traffic is being improved, taking into account the features of the infrastructure, as well as changes in traffic flows, in particular passenger flows at border areas. An important difference between the railway system of our country and neighboring EU countries is different tracks. The width of the track on our side of the border is mainly 1520 mm and 1435 mm in EU countries. This leads to a number of related features of rail transport. In addition, there are different approaches to traffic regulation. Therefore, it is essential to develop approaches for managing through transportation, in particular, on test sections of the railway track. This work is aimed at solving the current problem of organizing passenger transportation in areas adjacent to the Khyriv station. Both the 1,520 mm track and the combined 1,520/1,435 mm track are used on the site, which allows organising traffic with cars designed for the appropriate track width. A mathematical model of the movement of passengers using trains on different tracks is built - a combined track between two stations on the border with Poland (Nyzhankovychi-Starzhava) and a track with a width of 1520 mm (Sambir-Khyriv), taking into account the topology of the station with conditional distances and stations as the vertices of the corresponding graph. In view of the peculiarities of the stations, possible routes are considered for choosing a train formation scheme, namely, routes between stations of train formation and rotation. As a result, schedules for following passenger trains on border sections were constructed and studied, which allows for determining a rational scheme of train movement and their maintenance at stations. As an example, calculations were made for the Nizhankovychi-Starzhava section. It was found that in order to ensure the given passenger flow and organization of traffic on this section and adjacent tracks, it is necessary to introduce at least three passenger trains. The developed methodology can be used also for other border areas between the stations of Poland and Ukraine. The implementation of the proposed international route State Border – Nyzhankovychі – Khyriv – Starzhava – State Border along the 1435 mm track will allow our Polish neighbors to unite their two provinces with the help of their rolling stock passing through our territory, as well as to reduce the mileage of rolling stock and the distance between the two large cities of Poland. We, in turn, benefit from providing transport services and opening new international passenger routes, with further impleme
{"title":"Organization of passenger rail transportation on the section with the combined track Nyzhankovychi- Starzhava","authors":"Bohdan Gera, Y. Hermaniuk, V. Matviiv","doi":"10.23939/tt2023.01.029","DOIUrl":"https://doi.org/10.23939/tt2023.01.029","url":null,"abstract":"Passenger transportation by rail is an important component of ensuring cross-border cooperation between our country and neighboring EU countries. Transport transformations are being carried out on both sides of the border, and directives are being developed and implemented to establish uniform rules and standards for the successful operation of transport and passenger movement. At the same time, the organization of traffic is being improved, taking into account the features of the infrastructure, as well as changes in traffic flows, in particular passenger flows at border areas. An important difference between the railway system of our country and neighboring EU countries is different tracks. The width of the track on our side of the border is mainly 1520 mm and 1435 mm in EU countries. This leads to a number of related features of rail transport. In addition, there are different approaches to traffic regulation. Therefore, it is essential to develop approaches for managing through transportation, in particular, on test sections of the railway track. This work is aimed at solving the current problem of organizing passenger transportation in areas adjacent to the Khyriv station. Both the 1,520 mm track and the combined 1,520/1,435 mm track are used on the site, which allows organising traffic with cars designed for the appropriate track width. A mathematical model of the movement of passengers using trains on different tracks is built - a combined track between two stations on the border with Poland (Nyzhankovychi-Starzhava) and a track with a width of 1520 mm (Sambir-Khyriv), taking into account the topology of the station with conditional distances and stations as the vertices of the corresponding graph. In view of the peculiarities of the stations, possible routes are considered for choosing a train formation scheme, namely, routes between stations of train formation and rotation. As a result, schedules for following passenger trains on border sections were constructed and studied, which allows for determining a rational scheme of train movement and their maintenance at stations. As an example, calculations were made for the Nizhankovychi-Starzhava section. It was found that in order to ensure the given passenger flow and organization of traffic on this section and adjacent tracks, it is necessary to introduce at least three passenger trains. The developed methodology can be used also for other border areas between the stations of Poland and Ukraine. The implementation of the proposed international route State Border – Nyzhankovychі – Khyriv – Starzhava – State Border along the 1435 mm track will allow our Polish neighbors to unite their two provinces with the help of their rolling stock passing through our territory, as well as to reduce the mileage of rolling stock and the distance between the two large cities of Poland. We, in turn, benefit from providing transport services and opening new international passenger routes, with further impleme","PeriodicalId":343801,"journal":{"name":"Transport technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134158115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper presents the results of experimental studies of drivers` behavior when interacting with obstacles caused by parked vehicles. Today, parking cars on two-lane streets is a significant problem for drivers while driving as it creates obstacles. Drivers need to spot a parked car in time and perform a lane change maneuver. It affects the trajectories of vehicles and the functional state of the driver. The driver needs a certain amount of time to maneuver, which consists of the reaction time, the decision to change the lane, and the execution of the action. It complicates traffic conditions for the driver and creates danger for driving. If the driver does not receive information about the parking location on the street with high-speed traffic in time, the probability of danger increases significantly. In addition, drivers try to change the traffic lane, which is further occupied by parking, in advance to reduce the impact of parking on the functional state of their bodies. There is also a deviation in the cross-section of the street when the speed of movement increases relative to the parked car, which finally indicates a change in the position in the traffic lane. It was established that drivers individually choose the trajectories of changing the traffic lane by the speed of movement. In addition, each driver subjectively decides to start changing the traffic lane at his discretion when an obstacle occurs at a certain distance. Angular velocity was used as an indicator of the probability of finding an obstacle object in a dangerous state. Angular speed is the main parameter in the orientation of the driver and signals the danger. When the angular velocity was 0.015-0.03 rad/c, drivers tried to complete the maneuver and leave a certain distance from the obstacle (safety gap). It indicates some interval of angular velocity in relation to the perception of an obstacle object in space and the sense of danger. The resulting patterns of changing lanes by drivers allow for determining the safe distance to parking and ensuring traffic safety by using appropriate markings and road signs
{"title":"Regularities of the traffic lane change by the driver when interacting with car-obstacle","authors":"O. Prasolenko, Vitalii Chumachenko","doi":"10.23939/tt2023.01.001","DOIUrl":"https://doi.org/10.23939/tt2023.01.001","url":null,"abstract":"The paper presents the results of experimental studies of drivers` behavior when interacting with obstacles caused by parked vehicles. Today, parking cars on two-lane streets is a significant problem for drivers while driving as it creates obstacles. Drivers need to spot a parked car in time and perform a lane change maneuver. It affects the trajectories of vehicles and the functional state of the driver. The driver needs a certain amount of time to maneuver, which consists of the reaction time, the decision to change the lane, and the execution of the action. It complicates traffic conditions for the driver and creates danger for driving. If the driver does not receive information about the parking location on the street with high-speed traffic in time, the probability of danger increases significantly. In addition, drivers try to change the traffic lane, which is further occupied by parking, in advance to reduce the impact of parking on the functional state of their bodies. There is also a deviation in the cross-section of the street when the speed of movement increases relative to the parked car, which finally indicates a change in the position in the traffic lane. It was established that drivers individually choose the trajectories of changing the traffic lane by the speed of movement. In addition, each driver subjectively decides to start changing the traffic lane at his discretion when an obstacle occurs at a certain distance. Angular velocity was used as an indicator of the probability of finding an obstacle object in a dangerous state. Angular speed is the main parameter in the orientation of the driver and signals the danger. When the angular velocity was 0.015-0.03 rad/c, drivers tried to complete the maneuver and leave a certain distance from the obstacle (safety gap). It indicates some interval of angular velocity in relation to the perception of an obstacle object in space and the sense of danger. The resulting patterns of changing lanes by drivers allow for determining the safe distance to parking and ensuring traffic safety by using appropriate markings and road signs","PeriodicalId":343801,"journal":{"name":"Transport technologies","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127494235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
When predicting public transport routes in cities, important indicators should be considered: the duration of stay on the bus route, passenger flow on the bus route, points of attraction and the passenger’s average waiting time at stops. These indicators are the basis for planning the operation of city transport. In particular, predicting the duration of traffic by studying the average passenger’s waiting time at stops is an important planning tool for transport companies. Therefore, this study can improve the quality of scheduled services by reducing the gap between actual and scheduled travel time. This article discusses this relevance and, based on experimental evidence, points to the benefit of using studies of average passenger waiting times, especially considering population groups. In fact, most of the factors which affect public transport operation, as had been proven by previous studies, follow a definite mathematical methodology. The analysis was performed using the data from field studies of passenger flow at bus stops (Lviv, Ukraine). The study of passengers at stopping points makes it possible to improve the quality of public transport services (calculate travel duration between stops and the duration of stay at them more accurately). The duration of stay at selected objects depending on a number of passengers was studied. Also, there are given the results of a study of the waiting time of public transport passengers at bus stops are given. A comparison of the dependence of the bus waiting time on population groups was obtained. After receiving this information, system operators can design and adjust the data according to the estimated trip duration. Nevertheless, it is necessary to carry out research at different types of stops in different parts of cities to clarify these data and for a more detailed analysis.
{"title":"Study of the passengers average waiting time at public transport stops","authors":"M. Zhuk, V. Kovalyshyn, Vladyslav Zelemskyi","doi":"10.23939/tt2023.01.021","DOIUrl":"https://doi.org/10.23939/tt2023.01.021","url":null,"abstract":"When predicting public transport routes in cities, important indicators should be considered: the duration of stay on the bus route, passenger flow on the bus route, points of attraction and the passenger’s average waiting time at stops. These indicators are the basis for planning the operation of city transport. In particular, predicting the duration of traffic by studying the average passenger’s waiting time at stops is an important planning tool for transport companies. Therefore, this study can improve the quality of scheduled services by reducing the gap between actual and scheduled travel time. This article discusses this relevance and, based on experimental evidence, points to the benefit of using studies of average passenger waiting times, especially considering population groups. In fact, most of the factors which affect public transport operation, as had been proven by previous studies, follow a definite mathematical methodology. The analysis was performed using the data from field studies of passenger flow at bus stops (Lviv, Ukraine). The study of passengers at stopping points makes it possible to improve the quality of public transport services (calculate travel duration between stops and the duration of stay at them more accurately). The duration of stay at selected objects depending on a number of passengers was studied. Also, there are given the results of a study of the waiting time of public transport passengers at bus stops are given. A comparison of the dependence of the bus waiting time on population groups was obtained. After receiving this information, system operators can design and adjust the data according to the estimated trip duration. Nevertheless, it is necessary to carry out research at different types of stops in different parts of cities to clarify these data and for a more detailed analysis.","PeriodicalId":343801,"journal":{"name":"Transport technologies","volume":"46 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115673530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Automobile manufacturers, when designing new cars, are increasingly faced with the need to reduce the weight of components in order to achieve the required level of fuel consumption and environmental standards. As a result, internal combustion engines (ICEs) with a small number of cylinders are designed and manufactured, which allows to achieve an increase in output power due to increased pressure in the cylinder and more efficient fuel combustion. As a result of this, torsional vibrations occur on the crankshaft, which are transmitted and negatively affect the transmission, causing it to fail prematurely. The damping properties of dual-mass flywheel (DMF) in a straight line depend on their structure and design parameters. All modern DMF contain a certain amount of thick lubricant, which in one way or another improves its characteristics. But in addition to parts, flywheels that constantly work in an environment with lubricant, there are also elements between which dry friction occurs, which also affects the damping characteristics of the flywheel. Therefore, it can be assumed that its presence affects the elastic-damping properties of the DMF. The purpose of the work is to develop simulation models and study the effect of friction between DMF elements on oscillatory processes in the car transmission and to develop recommendations for reducing the load on DMF elements and transmission links. The effect of dry and viscous friction between the elements of a DMF on the damping of oscillations in the links of its elastic-damping system and the drive links of the car was studied. It is shown that an increase in the coefficient of dry friction between DMF elements from 0 to 0.3 does not provide a noticeable damping of oscillations in the drive links and tension in the DMF springs. The coefficient of viscous friction between the links of the DMF has a significant influence on the amount of tension in the springs of the DMF. To increase the resource of the DMF, it is advisable to install separators made of polymer material between the elastic links with a small coefficient of friction between it and the steel body of the DMF.
{"title":"The influence of friction between elements of dual-mass flywheel on oscillatory phenomena in a car transmission","authors":"Bohdan Kindratskyy, R. Litvin","doi":"10.23939/tt2022.02.072","DOIUrl":"https://doi.org/10.23939/tt2022.02.072","url":null,"abstract":"Automobile manufacturers, when designing new cars, are increasingly faced with the need to reduce the weight of components in order to achieve the required level of fuel consumption and environmental standards. As a result, internal combustion engines (ICEs) with a small number of cylinders are designed and manufactured, which allows to achieve an increase in output power due to increased pressure in the cylinder and more efficient fuel combustion. As a result of this, torsional vibrations occur on the crankshaft, which are transmitted and negatively affect the transmission, causing it to fail prematurely. The damping properties of dual-mass flywheel (DMF) in a straight line depend on their structure and design parameters. All modern DMF contain a certain amount of thick lubricant, which in one way or another improves its characteristics. But in addition to parts, flywheels that constantly work in an environment with lubricant, there are also elements between which dry friction occurs, which also affects the damping characteristics of the flywheel. Therefore, it can be assumed that its presence affects the elastic-damping properties of the DMF. The purpose of the work is to develop simulation models and study the effect of friction between DMF elements on oscillatory processes in the car transmission and to develop recommendations for reducing the load on DMF elements and transmission links. The effect of dry and viscous friction between the elements of a DMF on the damping of oscillations in the links of its elastic-damping system and the drive links of the car was studied. It is shown that an increase in the coefficient of dry friction between DMF elements from 0 to 0.3 does not provide a noticeable damping of oscillations in the drive links and tension in the DMF springs. The coefficient of viscous friction between the links of the DMF has a significant influence on the amount of tension in the springs of the DMF. To increase the resource of the DMF, it is advisable to install separators made of polymer material between the elastic links with a small coefficient of friction between it and the steel body of the DMF.","PeriodicalId":343801,"journal":{"name":"Transport technologies","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131576291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Today, the motorization level and the value of traffic flow on the street-road network have increased. Often this leads to an excessive load on the existing traffic management system, highways, and roads. As a result, the number and duration of traffic delays are increasing, especially within populated areas. The consequence of this is the formation of traffic jams, increase of fuel and lubricants consumption, noise pollution, and emissions of exhaust gases. Another, no less critical consequence is an increase in traffic accidents, particularly at unsignalized intersections. Therefore, a traffic light control system is often implemented at street intersections to increase traffic safety and reduce the number of conflicting flows. In addition, this system should be optimized for signalized objects. The object of the study is a signalized intersection of multi-lane streets located in the city. The main problem that needs to be solved is the reduction of the vehicles` delay duration at the approaches to such intersections, in particular with the use of appropriate organizational measures and planning of the traffic light control system. According to the study's results, regularities were revealed regarding the change in the traffic's delay duration depending on the share of the permissive signal and the duration of the traffic light's cycle at the street intersection. At the same time, the received modulation results in the PTV Vissim software environment indicate an increase in delay values with an increase in the duration of the traffic light cycle. However, an equally important influence factor is the share of the permissive signal, as it reduces to a certain extent the duration of vehicles in standby mode at the approaches to the signalized intersection. The obtained results are recommended to be used in both developing new traffic organization schemes at signalized street intersections and improving existing ones.
{"title":"The influence of the traffic light`s permissive signal share on the duration of traffic delays","authors":"T. Postranskyy, Kateryna Khoreva","doi":"10.23939/tt2022.02.063","DOIUrl":"https://doi.org/10.23939/tt2022.02.063","url":null,"abstract":"Today, the motorization level and the value of traffic flow on the street-road network have increased. Often this leads to an excessive load on the existing traffic management system, highways, and roads. As a result, the number and duration of traffic delays are increasing, especially within populated areas. The consequence of this is the formation of traffic jams, increase of fuel and lubricants consumption, noise pollution, and emissions of exhaust gases. Another, no less critical consequence is an increase in traffic accidents, particularly at unsignalized intersections. Therefore, a traffic light control system is often implemented at street intersections to increase traffic safety and reduce the number of conflicting flows. In addition, this system should be optimized for signalized objects. The object of the study is a signalized intersection of multi-lane streets located in the city. The main problem that needs to be solved is the reduction of the vehicles` delay duration at the approaches to such intersections, in particular with the use of appropriate organizational measures and planning of the traffic light control system. According to the study's results, regularities were revealed regarding the change in the traffic's delay duration depending on the share of the permissive signal and the duration of the traffic light's cycle at the street intersection. At the same time, the received modulation results in the PTV Vissim software environment indicate an increase in delay values with an increase in the duration of the traffic light cycle. However, an equally important influence factor is the share of the permissive signal, as it reduces to a certain extent the duration of vehicles in standby mode at the approaches to the signalized intersection. The obtained results are recommended to be used in both developing new traffic organization schemes at signalized street intersections and improving existing ones.","PeriodicalId":343801,"journal":{"name":"Transport technologies","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122415554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Optimizing transfers during public transport operations is one of the essential components of improving the quality of transport. Several factors influence the passenger's perception of a transfer: from the personal characteristics of the user of transport services to the parameters of the route network, trip characteristics and the design of transfer stops. The method of constructing Bayesian networks was used as one of the effective methods for solving problems of forecasting complex systems to find the relationship between different types of input data that affect the probability of making a transfer at a stop. The need for a transfer arises for a passenger when two reasons are combined: the need to make a trip between two transport areas and the lack of a direct public transport route between these transport areas. The number of needs for trip will depend on the number of residents in the departure zone, and the probability of not having a direct route will depend on the total number of routes departing from this zone. A simulation was carried out in the PTV Visum software environment (on the example of Lviv city) to determine the impact of these factors on the probability of changing at a stop. As a result, data were obtained on the total amount of passenger exchange at the stops of the public transportation system with distribution into the number of passengers disembarking at the stop, the number of passengers transferring at this stop, and the number of passengers going (up to 200 m) to another stop to transfer. The average waiting time for a transfer at a stop depends on both the number of routes passing through the stop and the regularity of traffic. Strict adherence to traffic schedules helps to reduce the average waiting time for a transfer. A comparison of the results of calculating the probability of a transfer at one of the stops using calculations based on field observation data and using modeling was carried out to check the adequacy of the modeling. The calculated probability is 0.16, the simulated probability is 0.12.
{"title":"Application of bayesian networks to estimate the probability of a transfer at a public transport stop","authors":"M. Zhuk, H. Pivtorak, I. Gits, Mariana Kozak","doi":"10.23939/tt2022.02.022","DOIUrl":"https://doi.org/10.23939/tt2022.02.022","url":null,"abstract":"Optimizing transfers during public transport operations is one of the essential components of improving the quality of transport. Several factors influence the passenger's perception of a transfer: from the personal characteristics of the user of transport services to the parameters of the route network, trip characteristics and the design of transfer stops. The method of constructing Bayesian networks was used as one of the effective methods for solving problems of forecasting complex systems to find the relationship between different types of input data that affect the probability of making a transfer at a stop. The need for a transfer arises for a passenger when two reasons are combined: the need to make a trip between two transport areas and the lack of a direct public transport route between these transport areas. The number of needs for trip will depend on the number of residents in the departure zone, and the probability of not having a direct route will depend on the total number of routes departing from this zone. A simulation was carried out in the PTV Visum software environment (on the example of Lviv city) to determine the impact of these factors on the probability of changing at a stop. As a result, data were obtained on the total amount of passenger exchange at the stops of the public transportation system with distribution into the number of passengers disembarking at the stop, the number of passengers transferring at this stop, and the number of passengers going (up to 200 m) to another stop to transfer. The average waiting time for a transfer at a stop depends on both the number of routes passing through the stop and the regularity of traffic. Strict adherence to traffic schedules helps to reduce the average waiting time for a transfer. A comparison of the results of calculating the probability of a transfer at one of the stops using calculations based on field observation data and using modeling was carried out to check the adequacy of the modeling. The calculated probability is 0.16, the simulated probability is 0.12.","PeriodicalId":343801,"journal":{"name":"Transport technologies","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129791870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The problem of noise pollution in cities becomes quite acute as soon as it comes to increasing the level of motorization. However, most researchers study the negative impact of traffic noise in general. In the era of sustainable mobility, there will be a trend to reduce the number of private vehicles on city streets. Still, the problem of acoustic load in residential areas will not be solved since public transport is a rather powerful source of traffic noise. The article solves the problem of determining the patterns of changes in the acoustic load from public transport vehicles at different speed modes and road surface. The article's objects of research are straight sections of public transport lines. The subject of the study is the patterns of changes in the noise level from public transport vehicles at different speeds, their position, and the type of surface. The obtained results indicate that the main range of noise pollution from public transport on straight sections is 75-85 dBA, and this level can vary by 15-20% depending on the type of line (trolley bus, bus, tram) and the type of road surface. The regularities of changes in the level of noise pollution, which were revealed in work, indicate that for each type of surface and type of public transport line, there are such values of traffic speeds, when they are reached, there is an overtime acoustic load on residential areas at specific distances from them. The obtained results differ from the currently existing scientific studies in that they consider the acoustic characteristics of clear public transport lines and not the traffic flow as a whole. Therefore, it becomes possible to determine the maximum and not the equivalent level of noise from public transport. The field of application of the results is transport planning of both new residential areas and areas of existing adjacent buildings. Thus, in the first case, recommendations were made regarding territorial gaps from the construction line to arterial streets with high volume of public transport, depending on its type and surface. On the other hand, recommendations have been established regarding the speed regime of public transport at different distances from existing buildings' lines.
{"title":"Patterns of changes in the acoustic characteristics on public transport linear segments","authors":"M. Afonin, Mykola Postranskyy","doi":"10.23939/tt2022.02.041","DOIUrl":"https://doi.org/10.23939/tt2022.02.041","url":null,"abstract":"The problem of noise pollution in cities becomes quite acute as soon as it comes to increasing the level of motorization. However, most researchers study the negative impact of traffic noise in general. In the era of sustainable mobility, there will be a trend to reduce the number of private vehicles on city streets. Still, the problem of acoustic load in residential areas will not be solved since public transport is a rather powerful source of traffic noise. The article solves the problem of determining the patterns of changes in the acoustic load from public transport vehicles at different speed modes and road surface. The article's objects of research are straight sections of public transport lines. The subject of the study is the patterns of changes in the noise level from public transport vehicles at different speeds, their position, and the type of surface. The obtained results indicate that the main range of noise pollution from public transport on straight sections is 75-85 dBA, and this level can vary by 15-20% depending on the type of line (trolley bus, bus, tram) and the type of road surface. The regularities of changes in the level of noise pollution, which were revealed in work, indicate that for each type of surface and type of public transport line, there are such values of traffic speeds, when they are reached, there is an overtime acoustic load on residential areas at specific distances from them. The obtained results differ from the currently existing scientific studies in that they consider the acoustic characteristics of clear public transport lines and not the traffic flow as a whole. Therefore, it becomes possible to determine the maximum and not the equivalent level of noise from public transport. The field of application of the results is transport planning of both new residential areas and areas of existing adjacent buildings. Thus, in the first case, recommendations were made regarding territorial gaps from the construction line to arterial streets with high volume of public transport, depending on its type and surface. On the other hand, recommendations have been established regarding the speed regime of public transport at different distances from existing buildings' lines.","PeriodicalId":343801,"journal":{"name":"Transport technologies","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115747693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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