Wyniki wyszukiwania - BazTech

1

To the comparative evaluation of three-unit lorry convoys of the different component systems by maneuverability

Sakhno Volodymyr, Poliakov Viktor, Lyashuk Oleg, Murovanyi Igor, Stelmashchuk Valeriy, Onyschuk Vasyl, Tson Oleg, Rozhko Natalia

Zeszyty Naukowe. Transport / Politechnika Śląska

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2023

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z. 121

189--201

EN

The article deals with the maneuverability of three-link road trains with various layout schemes. If a train has more than three links, difficulties arise in that the study of the movement of such a multi-link vehicle is significantly complicated due to the need to take into account the influence of a significant number of factors on the nature of the movement of all links. The interaction of neighboring units in the movement of a train is eventually distributed to the entire vehicle and causes certain deviations of the components of the train (modules) from the direction of movement specified by the driving link (tractor). Considering that a road train as a motor vehicle is a means of increased danger, when solving problems about the possibility of operating three- and multi-link road trains, it is one of the first to take steps towards theoretical studies of their maneuverability, the results of which will be the basis for answering many technical, organizational, and legal questions. Analysis of the calculation results showed that in the established circular path with the selected gear ratios of the control drives, none of the road trains met the requirements of DIRECTIVE 2002/7 / EC. From this, it follows that for three-link road trains, a fundamentally different control drive is needed, which can be a double control drive.

2

The study of stress-strain state elements of the truck semi-trailer body bottom

Lyashuk Oleg, Levkovych Mykhailo, Vovk Yuriy, Gevko Ivan, Stashkiv Mykola, Liubomyr Slobodian, Pyndus Yuriy

Zeszyty Naukowe. Transport / Politechnika Śląska

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2023

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z. 118

161--172

EN

Research on the influence of geometric parameters of body bottom elements on the stress-strain state (SSS) of the truck with the general application of computer simulation methods was conducted. The nature of the change in static stress and displacement depending on the change in the proportions of the crosssection of the channel at fixed geometric dimensions of the workpiece and the thickness of the workpiece and the bottom material of the body has been studied. Analytical, numerical and experimental methods were used in the study of the stress-strain state of the metal structure of car bodies. Its weight minimization is an important aspect of a truck body design. Because an excess weight leads to increased production costs, reduced payload and reduced fuel efficiency. According to the concept of weight reduction with the provision of a given strength, the body model with variable parameters of the bottom elements is modelled and analyzed. CAD - body models and analysis of the stress-strain state of the channels of the bottom of the bodies have been performed using the software package SolidWorks.

3

Complex evaluation of the efficiency of urban consolidation centers at the micro level

Savchenko Lidiia, Grygorak Mariya, Polishchuk Volodymyr, Vovk Yuriy, Lyashuk Oleg, Vovk Iryna, Khudobei Roman

Zeszyty Naukowe. Transport / Politechnika Śląska

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2022

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z. 115

135--159

EN

A methodical approach for the determination of economic and socio-environmental costs in the application of the city consolidation center at the micro level was proposed and tested on real data. Two options of urban delivery of small shipments are considered, in particular, for e-commerce - direct delivery and delivery through the micro-consolidation center. The system of indicators proposed in this work allows a detailed assessment of the economic component of direct and consolidated delivery, including transportation costs, the functioning of the consolidation center costs and costs for pedestrian delivery to the residential district customers. Socio-economic indicators allow considering the interests of other residents of the city, suffering from a dense traffic flow and harmful emissions from freight vehicles. The proposed method of integrated assessment was tested on real data of a micro district of the city. The results made it possible to estimate the proportion of each component of expenditures in the economic, socio-environmental and total costs for both delivery options. The analysis of the sensitivity of costs to changes in the input parameters showed the difference in the strength of influence, and the rating of influencing factors. The proposed method allows us to estimate the economic costs of all participants in the urban delivery process for small shipments, as well as to prove the rationality of using micro-consolidation to serve a micro district of a large city.

4

Scheduling technique of route vehicles on duplicating stretches

Azemsha Siarhei, Kravchenya Irina, Vovk Yuriy, Lyashuk Oleg, Vovk Iryna

Zeszyty Naukowe. Transport / Politechnika Śląska

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2021

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z. 113

5--16

EN

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.

5

Method of calculating the design parameters of a modulator anti-lock braking system with a high flow of working fluid

Zhilevich Mikhail, Ermilov Sergey, Kapski Denis, Vovk Yuriy, Lyashuk Oleg, Vovk Iryna

Zeszyty Naukowe. Transport / Politechnika Śląska

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2021

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z. 110

199--210

EN

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.

6

Blending control of the trolleybus traction and brake drives to enhance the braking efficiency of a vehicle

Safonau Andrei, Vovk Yuriy, Lyashuk Oleg, Khudobei Roman

Journal of Sustainable Development of Transport and Logistics

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2020

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Vol. 5, No. 2

49--61

EN

Widespread usage of emission free public transport is the preferred strategy in many cities to reduce a congestion and pollution from the road traffic. The trolleybus is a kind of urban public transport, i.e. a fully electric vehicle, which is considered as a promising tool to enhance the efficiency of public transport and to attain the goals of sustainable development and quality of city life. The operation control of service brake system and secondary brake system (the braking torque of traction electric motor) is realized with help of one pedal in the trolleybus. Thus, there are modes of the joint operation for these systems during the braking process. Authors focus on the development of rule-based algorithm for the blending control of traction electric motor and anti-lock braking system to enhance the overall braking efficiency of a vehicle. The mathematical model of the trolleybus braking dynamics was developed for this purpose. Test bench and ride tests on different road surfaces were carried out to determine the parameters of vehicle braking efficiency and to validate the developed mathematical model. The corresponding experimental data were used to analyse the efficiency of proposed rule-based strategy for the blending control of traction electric motor and anti-lock braking system of the trolleybus. As a result, the availability of proposed control algorithm is confirmed, which secures the required braking efficiency and provides a high braking stability of the vehicle.