Applied Sciences

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15 pages, 2168 KiB

Open AccessArticle

Experimental Study on a Reinforced Concrete Element to Extract the Durability Index with the Automated Visualization

by Seyed Mohammad Sadegh Lajevardi, Fereidoon Moghadas Nejad and Mehdi Ravanshadnia

Appl. Sci. 2022, 12(19), 9609; https://doi.org/10.3390/app12199609 - 24 Sep 2022

Cited by 3 | Viewed by 1513

Reinforced concrete (RC) durability is a crucial feature to estimate long-term quality and structural performance. The degradation model is vital for the resource planning of maintenance projects. This model will extract data by updating the status of structures and trending the components’ state [...] Read more.

Reinforced concrete (RC) durability is a crucial feature to estimate long-term quality and structural performance. The degradation model is vital for the resource planning of maintenance projects. This model will extract data by updating the status of structures and trending the components’ state over time in terms of durability. Surface erosion, spalling, cracks, and other defects exposed on RC components lead to increase factors adversely affecting concrete durability in structures. This research presents an approach based on automated visualization for extracting quantitative indexes as well as visual inspection without the subjective interspersion of humans or probable human errors during the inspection. The durability index (

D_{i}

) will extract according to damage probability and defects growth in order to extract the severity of failure and risk. Measurement operation by automated software has been double-checked by manual measurement tools, and data will verify randomly in this method. The results show that, in this component, the damaged area increases by 24% after a definite time. According to degradation models, this component may pass the relative thresholds for the limit for the state of operations to fail. This significant difference between expected time and designing time determines the

D_{i}

, equal to 5 out of 10. Full article

(This article belongs to the Special Issue Application of Intelligent Transportation Systems in Railway)

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17 pages, 1928 KiB

Open AccessArticle

A Maturity Model Proposal for Industrial Maintenance and Its Application to the Railway Sector

by Itxaro Errandonea, Unai Alvarado, Sergio Beltrán and Saioa Arrizabalaga

Appl. Sci. 2022, 12(16), 8229; https://doi.org/10.3390/app12168229 - 17 Aug 2022

Cited by 2 | Viewed by 2828

Abstract

Maintenance is one of the major concerns of the industrial sector. Acquiring better levels of maintenance maturity is one of the objectives to be achieved. Therefore, prescriptive maintenance is one of the areas of recent research. Current works in literature are focused on [...] Read more.

Maintenance is one of the major concerns of the industrial sector. Acquiring better levels of maintenance maturity is one of the objectives to be achieved. Therefore, prescriptive maintenance is one of the areas of recent research. Current works in literature are focused on specifics of maintenance strategies (from preventive to prescriptive), usually related to a fixed asset. No previous work has been identified regarding the methodology and guidelines to be followed to be able to evolve within the different strategies from a generic perspective. To address the lack of a methodology that shows a more evolutionary path between maintenance strategies, this paper presents Maintenance Maturity Model M3: a maturity model that identifies three areas of action, four levels of maturity, and the activities to be carried out in each of them to make progress in the maturity level of maintenance strategies. The implementation of prescriptive maintenance should be done in a gradual way, starting at the lowest levels. M3 approaches the problem from a broader perspective, analyzing the 18 different domains and the different levels of prior maturity to be considered for prescriptive maintenance. A study has also been carried out on the different maintenance actions and the applicability of the proposed M3 maturity model to the railway infrastructure maintenance is discussed. In addition, this paper also highlights future research lines and open issues. Full article

(This article belongs to the Special Issue Application of Intelligent Transportation Systems in Railway)

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12 pages, 1869 KiB

Open AccessArticle

Passenger Volumes and Dwell Times for Commuter Trains: A Case Study Using Automatic Passenger Count Data in Stockholm

by Ruben Alaric Kuipers and Carl-William Palmqvist

Appl. Sci. 2022, 12(12), 5983; https://doi.org/10.3390/app12125983 - 12 Jun 2022

Cited by 3 | Viewed by 1700

Abstract

This study investigates the relationship between passenger volumes and the frequency and size of dwell times for commuter trains. We use data collected by automatic passenger count systems in Stockholm and show that dwell times often take longer than scheduled. To understand the [...] Read more.

This study investigates the relationship between passenger volumes and the frequency and size of dwell times for commuter trains. We use data collected by automatic passenger count systems in Stockholm and show that dwell times often take longer than scheduled. To understand the effect of passenger volumes on delays, we use the frequencies of delays for different passenger volumes and delay sizes. We find that these frequencies differ significantly from a frequency distribution independent of passenger volumes, indicating that passenger volumes have an effect on the frequency of dwell time delays. Neglecting passenger volumes underestimates the frequency of delays in most cases, especially for smaller delays. Although the frequency of dwell time delays increases as passenger volumes increase, the same is not necessarily true for their size. The relationship between passenger volumes and delay sizes is thus non-linear, and it depends on scheduled dwell times. We conclude that small increases in dwell times can result in sharp increases in on-time performance but that only increasing dwell times is not sufficient. Measures to speed up the boarding and alighting process are also necessary. Full article

(This article belongs to the Special Issue Application of Intelligent Transportation Systems in Railway)

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24 pages, 1001 KiB

Open AccessArticle

Measures and Methods for the Evaluation of ATO Algorithms

by Patrick Bochmann and Birgit Jaekel

Appl. Sci. 2022, 12(9), 4570; https://doi.org/10.3390/app12094570 - 30 Apr 2022

Cited by 1 | Viewed by 1714

Abstract

There is increasing interest in automating train operations of mainline services, e.g., to increase network capacity. Automatic train operation (ATO) is already achieved by several pilot projects, but is still not implemented on a large scale. Functional, interoperability and performance tests are necessary [...] Read more.

There is increasing interest in automating train operations of mainline services, e.g., to increase network capacity. Automatic train operation (ATO) is already achieved by several pilot projects, but is still not implemented on a large scale. Functional, interoperability and performance tests are necessary before ATO can be introduced generally. Virtual preliminary analysis will contribute to the validation process to ensure a safe and successful implementation. This paper aims to present an approach that applies to the performance testing of ATO systems. Therefore, methods and test standards for technologies enabling automatic operation in other transport sectors are reviewed. The main findings have been adapted, transformed and combined to be used as a general strategy for virtual performance testing in the railway sector. Specifically, universal performance indicators commonly used in the railway sector, namely punctuality, accuracy, energy consumption, safety and comfort, are presented. They are refined by adding sub-indicators specific to the performance evaluation of ATO algorithms. A layer model for scenario description is adapted from the automotive sector, as well as the definition of different scenario types. Lastly, factors that can influence the performance of an ATO algorithm are identified. For demonstration purposes, a simple case study is conducted. Thereby we exemplarily show-cased the approach for ATO performance testing using a microscopic train simulator in combination with an ATO algorithm. Full article

(This article belongs to the Special Issue Application of Intelligent Transportation Systems in Railway)

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17 pages, 2296 KiB

Open AccessArticle

Environment Representations of Railway Infrastructure for Reinforcement Learning-Based Traffic Control

by István Lövétei, Bálint Kővári, Tamás Bécsi and Szilárd Aradi

Appl. Sci. 2022, 12(9), 4465; https://doi.org/10.3390/app12094465 - 28 Apr 2022

Cited by 2 | Viewed by 1862

Abstract

The real-time railway rescheduling problem is a crucial challenge for human operators since many factors have to be considered during decision making, from the positions and velocities of the vehicles to the different regulations of the individual railway companies. Thanks to that, human [...] Read more.

The real-time railway rescheduling problem is a crucial challenge for human operators since many factors have to be considered during decision making, from the positions and velocities of the vehicles to the different regulations of the individual railway companies. Thanks to that, human operators cannot be expected to provide optimal decisions in a particular situation. Based on the recent successes of multi-agent deep reinforcement learning in challenging control problems, it seems like a suitable choice for such a domain. Consequently, this paper proposes a multi-agent deep reinforcement learning-based approach with different state representational choices to solve the real-time railway rescheduling problem. Furthermore, comparing different methods, the proposed learning-based approaches outperform their competitions, such as the Monte Carlo tree search algorithm, which is utilized as a model-based planner, and also other learning-based methods that utilize different abstractions. The results show that the proposed representation has more significant generalization potential and provides superior performance. Full article

(This article belongs to the Special Issue Application of Intelligent Transportation Systems in Railway)

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20 pages, 3834 KiB

Open AccessArticle

Identity Management in Future Railway Mobile Communication System

by Evelina Pencheva, Ivaylo Atanasov and Ventsislav Trifonov

Appl. Sci. 2022, 12(9), 4293; https://doi.org/10.3390/app12094293 - 24 Apr 2022

Cited by 4 | Viewed by 1441

Abstract

The Future Railway Mobile Communication System (FRMCS) has emerged as a worldwide standard for railway communication. This technology enables the operational efficiency and safety of railways to be improved by providing mission critical communications, machine-type communication for the railway system on board, in [...] Read more.

The Future Railway Mobile Communication System (FRMCS) has emerged as a worldwide standard for railway communication. This technology enables the operational efficiency and safety of railways to be improved by providing mission critical communications, machine-type communication for the railway system on board, in addition to trackside telemetry and broadband connectivity for passengers. Different equipment types, users, and functional identities can be involved in communication, and each of them is uniquely identified. Identity management is an important part of the security functions provided by the FRMCS system. This paper presents a service-oriented approach to identity management functionality, enabling service composition for railway applications and service virtualization. This paper studies functionality for the initial registration and subsequent deregistration of railway devices, users, and their functional identities, in addition to the transfer of the registered identities between different FRMCS serving areas while the train moves. Two FRMCS services that follow the principles of representational state transfer architecture are proposed. Services’ functionality is illustrated by use cases, data types, and application programming interfaces that enable services to be interacted with. Identity registration status models are developed, formally described, and mathematically verified. Discussion of the applicability of the proposed services for the implementation of FRMCS security and safety functions is provided. The presented service-oriented approach features a satisfactory level of flexibility and versatility. Full article

(This article belongs to the Special Issue Application of Intelligent Transportation Systems in Railway)

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17 pages, 5391 KiB

Open AccessArticle

Towards Intelligent, Programmable, and Open Railway Networks

by Evelina Pencheva, Ivaylo Atanasov and Ventsislav Trifonov

Appl. Sci. 2022, 12(8), 4062; https://doi.org/10.3390/app12084062 - 17 Apr 2022

Cited by 3 | Viewed by 1817

Abstract

The virtualization and automation of network functions will be key features of future high-speed railway networks, which have to provide dependable, safe, and secure services. The virtualization of railway network functions will enable functions such as train control, train integrity protection, shunting control, [...] Read more.

The virtualization and automation of network functions will be key features of future high-speed railway networks, which have to provide dependable, safe, and secure services. The virtualization of railway network functions will enable functions such as train control, train integrity protection, shunting control, and trackside monitoring and maintenance to be virtualized and to be run on general-purpose hardware. Network function virtualization combined with edge computing can deliver dynamic, low-latency, and reliable services. The automation of railway operations can be achieved by embedding intelligence into the network to optimize the railway operation performance and to enhance the passenger experience. This paper presents an innovative railway network architecture that features distributed intelligence, function cloudification and virtualization, openness, and programmability. The focus is on time-tolerant and time-sensitive intelligent services designed to follow the principles of service-oriented architecture. The interaction between identified logical identities is illustrated by use cases. The paper provides some details of the design of the interface between distributed intelligent services and presents the results of an emulation of the interface performance. Full article

(This article belongs to the Special Issue Application of Intelligent Transportation Systems in Railway)

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10 pages, 409 KiB

Open AccessArticle

The Effects of Train Passes on Dwell Time Delays in Sweden

by Kah Yong Tiong, Carl-William Palmqvist and Nils O. E. Olsson

Appl. Sci. 2022, 12(6), 2775; https://doi.org/10.3390/app12062775 - 8 Mar 2022

Cited by 2 | Viewed by 1641

Abstract

Railway traffic is growing, resulting in a highly interconnected train network. Due to the interdependence between trains’ activities, a better understanding of train passes and their effects can ensure dispatching decisions made have minimum risk of delays. The impacts of train pass on [...] Read more.

Railway traffic is growing, resulting in a highly interconnected train network. Due to the interdependence between trains’ activities, a better understanding of train passes and their effects can ensure dispatching decisions made have minimum risk of delays. The impacts of train pass on dwell time delays were investigated using historical Swedish railway operation data. Three scenarios were considered by combining the scheduled and actual operations: passes that happened as scheduled, unscheduled passes that happened in operation, and scheduled passes that were cancelled. A logistic regression model was used to explore the effects of these passes on delays. The findings show that train passes rarely occurred as scheduled, more frequently they are cancelled or unscheduled. This implies that some adjustments are required to assure the timetable’s feasibility. This study also found that the odds of delays for the cancelled pass was about 9.80 times lower than scheduled pass but 2.6 times more often for an unscheduled pass than a scheduled pass. The different types of train passes were quantified using an odds ratio to make comparisons easier for dispatching decision-making. The approach used in this study can be extended to other types of train movements, such as the meeting of trains, as well as other delay-influencing factors. Full article

(This article belongs to the Special Issue Application of Intelligent Transportation Systems in Railway)

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