Pub Date : 2021-06-10DOI: 10.3846/TRANSPORT.2021.14574
C. Bosomworth, M. Spiryagin, S. Alahakoon, C. Cole
Rail foot flaws have the potential to cause broken rails that can lead to derailment. This is not only an extremely costly issue for a rail operator in terms of damage to rolling stock, but has significant flow-on effects for network downtime and a safe working environment. In Australia, heavy haul operators run up to 42.5 t axle loads with trains in excess of 200 wagons and these long trains produce very large cyclic rail stresses. The early detection of foot flaws before a broken rail occurs is of high importance and there are currently no proven techniques for detecting rail foot flaws on trains at normal running speeds. This paper shall focus on the potential use of thermography as a detection technique and begin investigating the components of heat transfer in the rail to determine the viability of thermography for detecting rail foot flaws. The paper commences with an introduction to the sources of heat generation in the rail and modelling approaches for the effects of bending, natural environmental factors and transverse defects. It concludes with two theoretical case studies on heat generated due to these sources and discusses how they may inform the development of a practical thermography detection methodology.
{"title":"MODELLING RAIL THERMAL DIFFERENTIALS DUE TO BENDING AND DEFECTS","authors":"C. Bosomworth, M. Spiryagin, S. Alahakoon, C. Cole","doi":"10.3846/TRANSPORT.2021.14574","DOIUrl":"https://doi.org/10.3846/TRANSPORT.2021.14574","url":null,"abstract":"Rail foot flaws have the potential to cause broken rails that can lead to derailment. This is not only an extremely costly issue for a rail operator in terms of damage to rolling stock, but has significant flow-on effects for network downtime and a safe working environment. In Australia, heavy haul operators run up to 42.5 t axle loads with trains in excess of 200 wagons and these long trains produce very large cyclic rail stresses. The early detection of foot flaws before a broken rail occurs is of high importance and there are currently no proven techniques for detecting rail foot flaws on trains at normal running speeds. This paper shall focus on the potential use of thermography as a detection technique and begin investigating the components of heat transfer in the rail to determine the viability of thermography for detecting rail foot flaws. The paper commences with an introduction to the sources of heat generation in the rail and modelling approaches for the effects of bending, natural environmental factors and transverse defects. It concludes with two theoretical case studies on heat generated due to these sources and discusses how they may inform the development of a practical thermography detection methodology.","PeriodicalId":23260,"journal":{"name":"Transport","volume":"24 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75038604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Urban air pollution has severe negative effects on health and the economy, especially in developing and industrializing countries, such as China and India. Although the transportation sector is widely acknowledged as among the largest contributors to urban air pollution, quantifying its causal effects on air pollution is challenging, as decisions to travel are endogenous with air quality. The spread of COVID-19 offers a unique opportunity for causal identification, as the pandemic directly affects decisions to travel but has little direct effect on air pollution. Leveraging the number of COVID-19 infections and COVID-19-related queries to online search engines as instruments for decisions to travel, controlling for two-way fixed effects, we quantify the effects of three public transportation subsectors (buses, railways, and taxis) and private vehicles on six primary air pollutants (CO, NO2, O3, PM2.5, PM10, and SO2) of 36 central cities of China, using two-stage ridge regression and double/debiased machine-learning models. Our work demonstrates that the negative effects of urban transportation on air quality are likely to be significantly underestimated without addressing endogeneity in the observational data. Further, our estimates after addressing endogeneity indicate that the effects of public transportation and private vehicles on different air pollutants are heterogeneous. Notably, our work shows that air pollution shifts the demand from mass transportation (buses and railways) to taxis. These findings have implications for sustainable transportation planning, operation, and policy evaluation.
{"title":"COVID-19, Urban Transportation, and Air Pollution","authors":"Juan Wang, Yifan Yu, Wendao Xue, Yong Tan","doi":"10.2139/ssrn.3859071","DOIUrl":"https://doi.org/10.2139/ssrn.3859071","url":null,"abstract":"Urban air pollution has severe negative effects on health and the economy, especially in developing and industrializing countries, such as China and India. Although the transportation sector is widely acknowledged as among the largest contributors to urban air pollution, quantifying its causal effects on air pollution is challenging, as decisions to travel are endogenous with air quality. The spread of COVID-19 offers a unique opportunity for causal identification, as the pandemic directly affects decisions to travel but has little direct effect on air pollution. Leveraging the number of COVID-19 infections and COVID-19-related queries to online search engines as instruments for decisions to travel, controlling for two-way fixed effects, we quantify the effects of three public transportation subsectors (buses, railways, and taxis) and private vehicles on six primary air pollutants (CO, NO2, O3, PM2.5, PM10, and SO2) of 36 central cities of China, using two-stage ridge regression and double/debiased machine-learning models. Our work demonstrates that the negative effects of urban transportation on air quality are likely to be significantly underestimated without addressing endogeneity in the observational data. Further, our estimates after addressing endogeneity indicate that the effects of public transportation and private vehicles on different air pollutants are heterogeneous. Notably, our work shows that air pollution shifts the demand from mass transportation (buses and railways) to taxis. These findings have implications for sustainable transportation planning, operation, and policy evaluation.","PeriodicalId":23260,"journal":{"name":"Transport","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2021-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72830624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-01DOI: 10.3846/TRANSPORT.2021.14996
I. Makarova, K. Shubenkova, A. Pashkevich
This paper considers managerial approaches to increase efficiency of the urban transport system such as promotion and integration of sustainable modes of transport, development of public transport route network, renewing the existing vehicle fleet and shift to environmental friendly fuel types in the public transport system. To assess such kind of efficiency, it is proposed to take into account the economic viability of suggested solutions as well as their influence on social sphere, environmental friendliness and sustainability of the urban transport system. The city of Naberezhnye Chelny (Russia) was chosen for the case study, where the following measures were modelled: changes of bus route network and choice of an optimal fleet on routes depending on passenger flow by hours of day. In addition, the efficiency of these measures were assessed. To evaluate the sustainability of the proposed route network, the method of “radar map” was used, which shows both strengths and weaknesses of selected indicators. Together with this evaluation, analysis of risks in managing the urban bus transportation was carried out.
{"title":"EFFICIENCY ASSESSMENT OF MEASURES TO INCREASE SUSTAINABILITY OF THE TRANSPORT SYSTEM","authors":"I. Makarova, K. Shubenkova, A. Pashkevich","doi":"10.3846/TRANSPORT.2021.14996","DOIUrl":"https://doi.org/10.3846/TRANSPORT.2021.14996","url":null,"abstract":"This paper considers managerial approaches to increase efficiency of the urban transport system such as promotion and integration of sustainable modes of transport, development of public transport route network, renewing the existing vehicle fleet and shift to environmental friendly fuel types in the public transport system. To assess such kind of efficiency, it is proposed to take into account the economic viability of suggested solutions as well as their influence on social sphere, environmental friendliness and sustainability of the urban transport system. The city of Naberezhnye Chelny (Russia) was chosen for the case study, where the following measures were modelled: changes of bus route network and choice of an optimal fleet on routes depending on passenger flow by hours of day. In addition, the efficiency of these measures were assessed. To evaluate the sustainability of the proposed route network, the method of “radar map” was used, which shows both strengths and weaknesses of selected indicators. Together with this evaluation, analysis of risks in managing the urban bus transportation was carried out.","PeriodicalId":23260,"journal":{"name":"Transport","volume":"31 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80913343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-10DOI: 10.3846/TRANSPORT.2021.14710
Huchang Liao, Zhihang Liu, A. Banaitis, E. Zavadskas, Xiang Zhou
New energy vehicles can improve the environmental pollution and thus benefit people’s healthy life. As a core component of new energy vehicles, batteries play a crucial role in the performance of new energy vehicles. There are many factors to be considered when selecting the battery for a new energy vehicle, so it can be regarded as a MCDM problem. This study builds a useful model by combining the PLTS with the UTASTAR method. Firstly, to represent the uncertain and fuzzy information of experts, we use the PLTSs to accurately express the linguistic information of experts. Given that the weights of criteria are often different and there are some preferences for criteria among experts, we use the BWM to determine the weights of criteria, which can deal with hesitant information and make the result suitable for experts’ preferences. The method proposed in this study can sort all alternatives based on a small amount of data. To show its applicability, we implement the method in the selection of new energy vehicle battery suppliers. Comparative analysis and discussions are made to verify the effectiveness of the method.
{"title":"BATTERY SUPPLIER DEVELOPMENT FOR NEW ENERGY VEHICLES BY A PROBABILISTIC LINGUISTIC UTASTAR METHOD","authors":"Huchang Liao, Zhihang Liu, A. Banaitis, E. Zavadskas, Xiang Zhou","doi":"10.3846/TRANSPORT.2021.14710","DOIUrl":"https://doi.org/10.3846/TRANSPORT.2021.14710","url":null,"abstract":"New energy vehicles can improve the environmental pollution and thus benefit people’s healthy life. As a core component of new energy vehicles, batteries play a crucial role in the performance of new energy vehicles. There are many factors to be considered when selecting the battery for a new energy vehicle, so it can be regarded as a MCDM problem. This study builds a useful model by combining the PLTS with the UTASTAR method. Firstly, to represent the uncertain and fuzzy information of experts, we use the PLTSs to accurately express the linguistic information of experts. Given that the weights of criteria are often different and there are some preferences for criteria among experts, we use the BWM to determine the weights of criteria, which can deal with hesitant information and make the result suitable for experts’ preferences. The method proposed in this study can sort all alternatives based on a small amount of data. To show its applicability, we implement the method in the selection of new energy vehicle battery suppliers. Comparative analysis and discussions are made to verify the effectiveness of the method.","PeriodicalId":23260,"journal":{"name":"Transport","volume":"15 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77046645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article analyzes the transport component of the country's economic security. As one of the connecting links in the economic chains between producers and end consumers, transport and transport infrastructure form the basis for the implementation of logistics, trade, investment and other operations aimed ultimately at the economic development of individual territories and regions, as well as the entire country as a whole.
{"title":"Transport Security as the Basis of Economic Stability in Russia","authors":"Sergei Taradonov, O. Antonov","doi":"10.2139/ssrn.3868783","DOIUrl":"https://doi.org/10.2139/ssrn.3868783","url":null,"abstract":"The article analyzes the transport component of the country's economic security. As one of the connecting links in the economic chains between producers and end consumers, transport and transport infrastructure form the basis for the implementation of logistics, trade, investment and other operations aimed ultimately at the economic development of individual territories and regions, as well as the entire country as a whole.","PeriodicalId":23260,"journal":{"name":"Transport","volume":"216 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2021-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77220477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-04DOI: 10.3846/TRANSPORT.2021.14676
Li Li, Dong Zhang, Xiaoyun Cheng, Ke Wang, Guiping Wang
This study analysed unbalanced traffic distribution on Triple Left-Turn Lanes (TLTLs) at signalized intersections that is caused by left-turn drivers’ unequal lane preferences. To develop statistical bonding between the multilane traffic flow and individual lane choices, the lane volumes are formatted as compositional data to subject the sum-constant constraint. One-way and two-way Compositional ANalysis Of VAriance (CANOVA) models were formulated respectively to estimate the independent effect of one factor and its joint effects with other factors on the multilane traffic distribution. TLTL volume composition was the dependent variable of the models, while the factors of geometric design and traffic control that could affect left-turn drivers’ lane choice were the independent variables. Results indicate that variance of vehicle turning curve, length of the upstream segment, the location of triple left-turn sign, signal phase / cycle length, could affect the traffic distribution, and its balance could be achieved at specific levels of a factor. The joint effects of some factor couples could improve the unbalanced traffic distribution while others could not work.
{"title":"A COMPOSITIONAL APPROACH FOR TRAFFIC DISTRIBUTION EVALUATION OF TRIPLE LEFT-TURN LANES FROM AN INDIVIDUAL PERSPECTIVE","authors":"Li Li, Dong Zhang, Xiaoyun Cheng, Ke Wang, Guiping Wang","doi":"10.3846/TRANSPORT.2021.14676","DOIUrl":"https://doi.org/10.3846/TRANSPORT.2021.14676","url":null,"abstract":"This study analysed unbalanced traffic distribution on Triple Left-Turn Lanes (TLTLs) at signalized intersections that is caused by left-turn drivers’ unequal lane preferences. To develop statistical bonding between the multilane traffic flow and individual lane choices, the lane volumes are formatted as compositional data to subject the sum-constant constraint. One-way and two-way Compositional ANalysis Of VAriance (CANOVA) models were formulated respectively to estimate the independent effect of one factor and its joint effects with other factors on the multilane traffic distribution. TLTL volume composition was the dependent variable of the models, while the factors of geometric design and traffic control that could affect left-turn drivers’ lane choice were the independent variables. Results indicate that variance of vehicle turning curve, length of the upstream segment, the location of triple left-turn sign, signal phase / cycle length, could affect the traffic distribution, and its balance could be achieved at specific levels of a factor. The joint effects of some factor couples could improve the unbalanced traffic distribution while others could not work.","PeriodicalId":23260,"journal":{"name":"Transport","volume":"36 1","pages":"110-122"},"PeriodicalIF":1.7,"publicationDate":"2021-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87423988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-02DOI: 10.3846/TRANSPORT.2021.14519
M. Milenković, S. Val, Dejan Lutovac, N. Bojovic, Nikola Knezevic
Freight transport represents a very dynamic and competitive market with high requirements for reliability, lead time, cost, flexibility and visibility of transport service. Rationalization of transport service, reduced travelling time and reliable delivery times represent the main prerequisites for lowering the costs and increasing the efficiency of entire transport chain. These performance indicators actually represent the main factors affecting the shipper’s mode choice. Improvement of these factors could be achieved by improved coordination between rail and non-rail-related stakeholders involved in freight transport service planning and realization. Since this solution requires a multi-stakeholder collaboration, it is needed to evaluate the interests of each of them in order to derive a preferred set of indicators, which will facilitate a collectively accepted solution and value alignment of all involved actors. In this paper, the preferred set of indicators was selected by using the DEcision MAking Trial and Evaluation Laboratory (DEMATEL) model technique integrated with the Analytic Network Process (ANP). DEMATEL is applied to analyse the causal relationships among the relevant dimensions and among the criteria within each dimension. The causal relationships are then used in ANP for determining the weights of the criteria. An empirical case study based on implementation of information sharing platform in rail intermodal transport chain is presented to demonstrate the effectiveness of the proposed approach. Based on this study the attributes that belong to reliability (“departing / arriving on-time”, “cancelled services”), lead time (“idle time”) and investment cost (“organizational culture”, “business process redesign”) dimensions represent five the most critical factors for obtaining a collectively accepted solution. This effective evaluation model enables policy makers and stakeholders in transportation / logistics to understand and conduct appropriate actions towards fulfilling the objectives for greener transportation.
货运是一个充满活力和竞争的市场，对运输服务的可靠性、交货时间、成本、灵活性和可视性有很高的要求。运输服务的合理化、缩短运输时间和可靠的交货时间是降低整个运输链成本和提高效率的主要前提。这些绩效指标实际上代表了影响托运人模式选择的主要因素。改善这些因素可以通过改善铁路和非铁路相关利益相关者之间的协调来实现，这些利益相关者参与货运服务的规划和实现。由于此解决方案需要多方利益相关者的协作，因此需要评估每个利益相关者的利益，以便得出一组首选指标，这将促进所有相关参与者共同接受的解决方案和价值一致性。本文采用DEcision MAking Trial and Evaluation Laboratory (DEMATEL)模型技术和Analytic Network Process (ANP)相结合的方法选择优选指标集。DEMATEL用于分析相关维度之间以及每个维度内标准之间的因果关系。然后在ANP中使用因果关系来确定标准的权重。以铁路多式联运链中信息共享平台的实施为例，验证了该方法的有效性。基于本研究，属于可靠性(“准时出发/到达”，“取消服务”)，交货时间(“空闲时间”)和投资成本(“组织文化”，“业务流程重新设计”)维度的属性代表了获得集体接受的解决方案的五个最关键因素。这种有效的评估模型使运输/物流的政策制定者和利益相关者能够理解并采取适当的行动，以实现绿色运输的目标。
{"title":"EVALUATION OF THE INNOVATIVE VALUE PROPOSITION FOR THE RAIL FREIGHT TRANSPORT: AN INTEGRATED DEMATEL–ANP APPROACH","authors":"M. Milenković, S. Val, Dejan Lutovac, N. Bojovic, Nikola Knezevic","doi":"10.3846/TRANSPORT.2021.14519","DOIUrl":"https://doi.org/10.3846/TRANSPORT.2021.14519","url":null,"abstract":"Freight transport represents a very dynamic and competitive market with high requirements for reliability, lead time, cost, flexibility and visibility of transport service. Rationalization of transport service, reduced travelling time and reliable delivery times represent the main prerequisites for lowering the costs and increasing the efficiency of entire transport chain. These performance indicators actually represent the main factors affecting the shipper’s mode choice. Improvement of these factors could be achieved by improved coordination between rail and non-rail-related stakeholders involved in freight transport service planning and realization. Since this solution requires a multi-stakeholder collaboration, it is needed to evaluate the interests of each of them in order to derive a preferred set of indicators, which will facilitate a collectively accepted solution and value alignment of all involved actors. In this paper, the preferred set of indicators was selected by using the DEcision MAking Trial and Evaluation Laboratory (DEMATEL) model technique integrated with the Analytic Network Process (ANP). DEMATEL is applied to analyse the causal relationships among the relevant dimensions and among the criteria within each dimension. The causal relationships are then used in ANP for determining the weights of the criteria. An empirical case study based on implementation of information sharing platform in rail intermodal transport chain is presented to demonstrate the effectiveness of the proposed approach. Based on this study the attributes that belong to reliability (“departing / arriving on-time”, “cancelled services”), lead time (“idle time”) and investment cost (“organizational culture”, “business process redesign”) dimensions represent five the most critical factors for obtaining a collectively accepted solution. This effective evaluation model enables policy makers and stakeholders in transportation / logistics to understand and conduct appropriate actions towards fulfilling the objectives for greener transportation.","PeriodicalId":23260,"journal":{"name":"Transport","volume":"5 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2021-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83592391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-30DOI: 10.3846/TRANSPORT.2021.14622
V. Savkiv, Roman Mykhailyshyn, P. Maruschak, V. Kyrylovych, F. Duchoň, Lubos Chovanec
Invention proposes an adaptive gripping device of an industrial robot, which combines functions of capturing different-shape manipulation objects with control of deviations from the shape of these objects. The device is a T-shaped frame with three Bernoulli grips pivotally mounted thereon and a pneumatic sensor. Analytical dependencies are presented for determination of design parameters of adaptive gripping device and calculation of required lifting force of each of Bernoulli Gripping Device (BGD). Formula is derived for determining its position of pneumatic sensor on frame of gripping devices. In the ANSYS-CFX software environment, numerical simulation of airflow dynamics in the gap between the cooperating BGD surfaces and the offset mirror antenna plate blank. The simulation was based on the Reynolds-Averaged Navier–Stokes (RANS) equations of viscous gas dynamics, the Shear Stress Transport (SST) model of turbulence, and the y model of laminar–turbulent transition. As a result of the simulation, the effect of the curvature radius of the surface of the plates of offset mirror antennas on the BGD power characteristics was determined.
本发明提出了一种工业机器人的自适应夹持装置，该装置将捕获不同形状的操作对象的功能与控制偏离这些对象形状的功能相结合。该装置是一个t形框架，上面有三个伯努利手柄和一个气动传感器。给出了自适应夹持装置设计参数的确定和各伯努利夹持装置所需提升力的计算的解析依赖关系。导出了气动传感器在夹持装置框架上的位置确定公式。在ANSYS-CFX软件环境下，对协同BGD曲面与偏置镜天线板空白间隙内的气流动力学进行了数值模拟。模拟基于粘性气体动力学的reynolds - average Navier-Stokes (RANS)方程、湍流的剪切应力输运(SST)模型和层流-湍流过渡的y模型。通过仿真，确定了偏置反射镜天线表面曲率半径对BGD功率特性的影响。
{"title":"GRIPPING DEVICES OF INDUSTRIAL ROBOTS FOR MANIPULATING OFFSET DISH ANTENNA BILLETS AND CONTROLLING THEIR SHAPE","authors":"V. Savkiv, Roman Mykhailyshyn, P. Maruschak, V. Kyrylovych, F. Duchoň, Lubos Chovanec","doi":"10.3846/TRANSPORT.2021.14622","DOIUrl":"https://doi.org/10.3846/TRANSPORT.2021.14622","url":null,"abstract":"Invention proposes an adaptive gripping device of an industrial robot, which combines functions of capturing different-shape manipulation objects with control of deviations from the shape of these objects. The device is a T-shaped frame with three Bernoulli grips pivotally mounted thereon and a pneumatic sensor. Analytical dependencies are presented for determination of design parameters of adaptive gripping device and calculation of required lifting force of each of Bernoulli Gripping Device (BGD). Formula is derived for determining its position of pneumatic sensor on frame of gripping devices. In the ANSYS-CFX software environment, numerical simulation of airflow dynamics in the gap between the cooperating BGD surfaces and the offset mirror antenna plate blank. The simulation was based on the Reynolds-Averaged Navier–Stokes (RANS) equations of viscous gas dynamics, the Shear Stress Transport (SST) model of turbulence, and the y model of laminar–turbulent transition. As a result of the simulation, the effect of the curvature radius of the surface of the plates of offset mirror antennas on the BGD power characteristics was determined.","PeriodicalId":23260,"journal":{"name":"Transport","volume":"74 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76480423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-30DOI: 10.3846/TRANSPORT.2021.14370
A. Borucka
In the analysis of the readiness of means of transport, the Markov and semi-Markov processes are particularly applicable, allowing for the description of the usage process over long periods of time, determination of indicators of the exploitability and readiness of the used set of objects, as well as simulation of long-term forecasts of the usage process results. The studies presented in the literature usually concern the theoretical side of the matter, mainly the construction of formal models of the process of changing the operating states of a vehicle. Less attention is paid to the empirical side, especially with regard to the actual conditions of use. Examples of experimental observations presented in the literature most often concern individual cases. This paper lists selected irregularities and presents an example of a study of a real transport system based on semi-Markov processes.
{"title":"METHOD OF TESTING THE READINESS OF MEANS OF TRANSPORT WITH THE USE OF SEMI-MARKOV PROCESSES","authors":"A. Borucka","doi":"10.3846/TRANSPORT.2021.14370","DOIUrl":"https://doi.org/10.3846/TRANSPORT.2021.14370","url":null,"abstract":"In the analysis of the readiness of means of transport, the Markov and semi-Markov processes are particularly applicable, allowing for the description of the usage process over long periods of time, determination of indicators of the exploitability and readiness of the used set of objects, as well as simulation of long-term forecasts of the usage process results. The studies presented in the literature usually concern the theoretical side of the matter, mainly the construction of formal models of the process of changing the operating states of a vehicle. Less attention is paid to the empirical side, especially with regard to the actual conditions of use. Examples of experimental observations presented in the literature most often concern individual cases. This paper lists selected irregularities and presents an example of a study of a real transport system based on semi-Markov processes.","PeriodicalId":23260,"journal":{"name":"Transport","volume":"52 1","pages":"75-83"},"PeriodicalIF":1.7,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83716051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-21DOI: 10.3846/TRANSPORT.2021.14964
J. Tretjakovas, A. Cereska
The purpose of trucks is very diverse, but the main purpose is freight transportation. When cargos are transported, the truck’s suspensions are heavily loaded, so failures also occur most often in the suspension elements. For axles of trailers – tubular construction failures occur, they crack. Axle failure investigations are required to determine the cause of the failure. The paper analyses three-axle truck trailer suspension. Axle failure analysis and axial deformation modelling were performed to determine trends and causes of truck trailer suspension axle failures. Different cases with axles of tubular construction with wall thicknesses of 9 and 11 mm were modelled. The paper presented visual failure analysis of truck trailers suspension axles and finite element modelling results of axle’s deformation of different geometrical parameters. The results were discussed and conclusions were drawn.
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