| 1. |
- Asplund, Fredrik, et al.
(author)
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Tool Integration Beyond Wasserman
- 2011
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In: Advanced Information Systems Engineering Workshops. - Berlin : Springer-Verlag. - 9783642220555 ; , s. 270-281
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Conference paper (peer-reviewed)abstract
- The typical development environment today consists of many specialized development tools, which are partially integrated, forming a complex tool landscape with partial integration. Traditional approaches for reasoning about tool integration are insufficient to measure the degree of integration and integration optimality in today’s complex tool landscape. This paper presents a reference model that introduces dependencies between, and metrics for, integration aspects to overcome this problem. This model is used to conceive a method for reasoning about tool integration and identify improvements in an industrial case study. Based on this we are able to conclude that our reference model does not detract value from the principles that it is based on, instead it highlights improvements that were not well visible earlier. We conclude the paper by discussing open issues for our reference model, namely if it is suitable to use during the creation of new systems, if the used integration aspects can be subdivided further to support the analysis of secondary issues related to integration, difficulties related to the state dependency between the data and process aspects within the context of developing embedded systems and the analysis of non-functional requirements to support tool integration.
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| 2. |
- Asplund, Fredrik, et al.
(author)
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Tool Integration, from Tool to Tool Chain with ISO 26262
- 2012
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In: SAE Technical Paper Series. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191.
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Conference paper (peer-reviewed)abstract
- The use of innovative power sources in future cars has long-ranging implications on vehicle safety. We studied these implications in the context of the guidance on software tool qualification in the then current ISO 26262 draft, when building an urban concept vehicle to participate in the 2011 Shell Eco-Marathon. While the guidance on tool qualification is detailed, the guidance in regard to tools integrated into tool chains is limited. It only points out that the environment that tools execute in needs to be taken into consideration.In this paper we clarify the implications of tool chains on tool qualification in the context of ISO 26262 by focusing on answering two questions; first, are there parts of the development environment related to tool integration that are likely to fall outside of tool qualification efforts as currently defined by ISO 26262; secondly, can we define if, and -if so- how, tool integration is affected by ensuring functional safety.We conclude by identifying two areas related to tool integration that are likely to fall outside the tool qualification efforts (data integrity and process logic) and describing how different constraints imposed by ISO 26262 in relation to tool qualification conflict when tool integration is improved (improvements aimed at supporting completeness, consistency and the safety lifecycle vs. tool qualification cost).We are able to make additional conclusions in relation to the State of the Art discussion on software tool qualification according to ISO 26262. First, reference tool chains and guidelines on which characteristics tool qualification should ensure for tool chains are needed to complement ISO 26262. Secondly, guidance on tool integration can be found in the completeness characteristic, the consistency characteristic and the ISO 26262 safety lifecycle process. Finally, qualification efforts should ideally target tool chains rather than individual tools.
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| 3. |
- Asplund, Fredrik, et al.
(author)
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Towards the Automated Qualification of Tool Chain Design
- 2012
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In: SAFECOMP 2012 Workshops. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783642336744 ; , s. 392-399
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Conference paper (peer-reviewed)abstract
- The development of safety-critical embedded systems is supported by a number of development tools, which are increasingly integrated into automated tool chains. Safety standards require these tool chains to be qualified, which is costly and requires a large effort. To reduce cost and effort tool chains can be composed of pre-qualified tools and then themselves pre-qualified by identifying the parts of tool chain software that have an impact on safety more exactly. In this paper we propose the use of a modeling language to describe this tool chain composition. This allows us to reduce effort even further by automatically analyzing the tool chain model for safety issues. It also promises to reduce the effort and cost of later steps in the deployment of the tool chain by formalizing the communication of safety issues and automating the generation of code for tool chain software.
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| 4. |
- Asplund, Matthias, et al.
(author)
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A Nordic heavy haul experience and best practices
- 2017
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In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit. - : Sage Publications. - 0954-4097 .- 2041-3017. ; 231:7, s. 794-804
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Journal article (peer-reviewed)abstract
- This article summarizes the experiences gained at the Nordic heavy haul line “Malmbanan” located in Northern Sweden and Norway during the years 2007 to 2015 and the resulting best practice. Unique long-term information of field trials and monitoring from the on-going development for maintenance of rail and wheel has been described. The reported results come from the rail profile measurements using MiniProf and HC-recordings with Eddy-current devices and visual inspection on 43 test sections. The monitoring has been continuous since the project started, to reveal a deep insight into the complex wheel–rail interaction and provide understanding of the effect of applying optimized specifications. This was particularly important in view of the increasing traffic load that contributed to doubling of the yearly grinding campaigns. This article presents in particular the new MB5 profile, the wear rate behaviour between two different curves, impacts of gauge widening on rail rolling contact fatigue and the speed of gauge widening as well as the seasonal impact on the crack propagation. The presently applied maintenance strategy is discussed together with other experiences. The article finishes with some conclusions and an outlook into further work.
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| 5. |
- Asplund, Matthias, et al.
(author)
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A study of railway wheel profile parameters used as indicators of an increased risk of wheel defects
- 2016
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In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit. - : SAGE Publications. - 0954-4097 .- 2041-3017. ; 230:2, s. 323-334
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Journal article (peer-reviewed)abstract
- The capacity demands on the railways will increase in the future, as well as the demands for a robust and available system. The availability of the railway system is dependent on the condition of the infrastructure and the rolling stock. To inspect the rolling stock and to prevent damage to the track due to faulty wheels, infrastructure managers normally install wayside monitoring systems along the track. Such systems indicate, for example, wheels that fall outside the defined safety limits and have to be removed from service to prevent further damage to the track. Due to the nature of many wayside monitoring systems, which only monitor vehicles at definite points along the track, damage may be induced on the track prior to fault detection at the location of the system. Such damage can entail capacity-consuming speed reductions and manual track inspections before the track can be opened for traffic again. The number of wheel defects must therefore be kept to a minimum. In this paper wheel profile parameters measured by a wayside wheel profile measurement system, installed along the Swedish Iron Ore Line, are examined and related to warning and alarm indications from a wheel defect detector installed on the same line. The study shows that an increased wheel wear, detectable by changes in the wheel profile parameters could be used to reduce the risk of capacity-consuming wheel defect failure events and its reactive measures.
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| 6. |
- Asplund, Matthias, et al.
(author)
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Assessment of the data quality of wayside wheel profile measurements
- 2016
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In: International Journal of COMADEM. - 1363-7681. ; 19:3, s. 19-25
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Journal article (peer-reviewed)abstract
- To evaluate the behaviour and the condition of a railway wheel in relation to performance and safety criteria, the wheel profile can be measured. This can be achieved using manual methods or automatic systems mounted along the railway track. Such systems have the advantage that they can measure a vast number of profiles, enabling new possibilities of performing statistical analyses of the results and pinpointing bad wheels at an early stage. These wayside measurement systems are, however, subjected to different environmental conditions that can affect the data quality of the measurement. If one is to be able to use automatic wheel profile measurements, the data quality has to be controlled in order to facilitate maintenance decisions. This paper proposes a method for the data quality assessment of an automatic wayside condition monitoring system measuring railway rolling stock wheels. The purpose of the assessment method proposed in this paper is to validate individual wheel profile measurements to ensure the accuracy of the wheel profile measurement data and hence the following data analysis. The method consists of a check routine based on the paired t-test, which uses a hypothesis test to verify if the null hypotheses are true. The check routine compares measurements of passing wheels rolling to a certain destination with measurements of the same wheels returning from that destination. The routine of comparing measurements of the same wheel, which is performed by four sensors (one on each side of each rail), will ensure that the sensors generate the same data for the same sample. A case study is presented which shows how the method can detect a faulty setup of the measurement system and prevent incorrect interpretations of the data from different measurement units in the same system. The paper ends with a discussion and conclusions concerning the improvements that are presented.
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| 7. |
- Asplund, Matthias, et al.
(author)
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Automatic laser scanning of wheel profiles: condition monitoring to achieve greater capacity for existing infrastructure in an extreme climate
- 2013
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In: Automatic laser scanning of wheel profiles. - India : Indian Railways, the host of 10th IHHA Conferance. - 9788192651910 ; , s. 445-451
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Conference paper (peer-reviewed)abstract
- The Iron Ore Line (Malmbanan) is a 473 km long track section located in northern Sweden and has been in operation since 1903. It is mainly used to transport iron ore and pellets from the mines in Kiruna and Malmberget to Narvik Harbour (Norway) in the northwest and Luleå Harbour (Sweden) in the southeast. The track section on the Swedish side is owned by the Swedish Government and managed by Trafikverket (the Swedish Transport Administration), while the ore wagons are owned and managed by the freight operator (LKAB). Due to the high axle load exerted by the iron ore transports, 30 tonnes, and the high demand for a constant ore/pellets flow, the track and wagons must be monitored and maintained on a regular basis. The condition of the wagon wheel profile is one of the most important aspects in this procedure. For this reason an automatic laser-based wheel profile monitoring system has been installed on this line. This system can automatically measure and monitor the wagon wheel profiles at speeds up to 130 km/h. The system was installed and is being operated in a collaboration project between the freight operator and infrastructure manager. The information generated is collected by the e-maintenance personnel at Luleå Railway Research Center (JVTC). The measurements will be used to diagnose the condition of the wheel and rail, and to optimize their maintenance further. This paper presents a study of the selection and the installation of the equipment. Some results from the measurements are shown. The system’s availability during performance in extreme climate conditions, with severe cold and large quantities of snow, is presented. Then the benefits and perceived challenges of the system are discussed. Some potential improvements in rail and wheel maintenance, to achieve more capacity, are analysed.
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| 8. |
- Asplund, Matthias, et al.
(author)
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Combating curve squeal noise
- 2016
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In: Combating curve squeal noise.
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Conference paper (peer-reviewed)abstract
- Society demand for more sustainable transports is increasing, starting a modal shift from road to railway. The resulting increase in railway traffic intensity is leading to more activities on the track, even during the night time. For many years continuous urbanization has been resulting in a higher density of residents in areas close to railway tracks. The combination of these factors is raising the issue of noise disturbances from railway transports, which is forcing infrastructure managers to take action to combat noise from railway traffic systematically. There are different types of noise emanating from railways and one of the most annoying is curve squeal noise. This paper deals with the curve squeal phenomenon, the places where it occurs, and different methods for reducing it. The curving behaviour of a vehicle plays an important role in the generation of curve squeals, and therefore the way in which different rail profiles affect the capability to steer in a sharp curve is dealt within this paper. The paper is based on two case studies with investigated curves in urban regions that suffer from squeal noise, and in which comparisons between measurements and simulations were performed. The outcome of these studies is a workflow for combating squeal noise, results concerning the effects of a top-of-rail friction modifier on noise mitigation, and a proposed rail profiles for improving the steering capability of vehicles.
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| 9. |
- Asplund, Matthias, et al.
(author)
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Comparison of TOR lubrication systems on the iron ore line
- 2015
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Conference paper (peer-reviewed)abstract
- The Iron Ore Line (IOL) is a 473 km long track section which is located in northern Sweden and northern Norway, and has been in operation since 1903. The northern part is located above the Arctic Circle. The IOL is mainly used to transport iron ore and pellets from the mines in Kiruna and Malmberget to Narvik Harbour (Norway) in the northwest and Luleå Harbour (Sweden) in the southeast. The track section on the Swedish side is owned by the Swedish Government and managed by Trafikverket (the Swedish Transport Administration), while the ore wagons are owned and managed by the freight operator (LKAB).The IOL has seen a considerable increase in the axle load and traffic volume recently. Due to the introduction of new vehicles with a 30-ton axle load, the rails were gradually replaced between 2006 and 2009 with heavier rails, generally with a steel grade of 350LHT. The rail and wheels suffer from rolling contact fatigue (RCF) due to high friction between the rail and wheel. To control the wheel-rail interface, wayside top-of-rail (TOR) lubrication can be used. The reliability of the TOR lubrication equipment and the lubricants in northern conditions has not been investigated, and the long-term maintenance support required for TOR lubrication is unknown to the infrastructure manager. Furthermore, can TOR lubrication reduce the rail and wheel maintenance costs? This project has been conducted through collaboration between the main operator (LKAB) and the infrastructure manager (Trafikverket); the costs have been shared and the results analysed in collaboration. This paper describes the test period of two years, using two different TOR lubrication systems in two different places on the IOL, one situated in the northern loop and one in the southern loop, each with different operational conditions. The paper shows the actual operational conditions for the pilot test locations, the friction value close to the systems, the rail forces during the test period and some results for the noise measurements. Furthermore, the paper includes the improvements of system resulting from the test operation, and ends with recommendations for the continued use of TOR lubrication on the IOL.
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| 10. |
- Asplund, Matthias, et al.
(author)
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Condition monitoring and e-maintenance solution of railway wheels
- 2014
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In: Journal of Quality in Maintenance Engineering. - 1355-2511 .- 1758-7832. ; 20:3, s. 216-232
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Journal article (peer-reviewed)abstract
- Purpose – The purpose of this paper is to investigate the failure-driven capacity consumption of wheels on the track, to determine whether there are some relations to vehicle wheel configurations that show a larger amount of failures, and to ascertain the influence of the temperature and the travelling direction of the train on the number of events. This information can be used to develop prognostic health management (PHM) so that more track capacity can be gained without modifications, re-building or re-investments. Design/methodology/approach – This paper presents a study of 1,509 warning and alarm events concerning train wheels. The data come from the infrastructure manager’s wheel defect detectors and wheel profile measurement system. These data have been analysed and processed to find patterns and connections to different vehicles, travelling directions and temperatures. Findings – Lower temperatures increase the probability of wheels having high vertical forces. Trains with different wheel configurations show different results. With high vertical forces, the probability of wheel failures at axle 6 and 7 is high for locomotives with two bogies and three axles in each bogie (2x3). All these findings can be used to develop the maintenance, monitoring and inspection principles for wheels. Practical implications – The inspection of wheels to detect failures needs to be more frequent on days and in seasons with lower temperatures. The wheel inspection should be performed more frequently at axle 6 and 7 for locomotives with a 2x3 wheel configuration. The inspection and monitoring of wheels need to be carried out more carefully for trains travelling south, to avoid a large amount of wheels with high force levels rolling in the southern direction. Originality/value – The analysis carried out in this paper identifies important factors that correlate with the high occurrence of wheel defects. It also proposes a conceptual e-maintenance model for the combination of wheel condition monitoring data from different system. The value of this study is the provision of information to support prognostic and health management system to support proactive maintenance.
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| 11. |
- Asplund, Matthias, et al.
(author)
-
Condition monitoring of rolling stock wheels : approach towards maintenance decision making
- 2014
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In: 27th International Congress on Condition Monitoring and Diagnostic Engineering (COMADEM 2014). - : COMADEM International.
-
Conference paper (peer-reviewed)abstract
- Due to the more or less fixed inherent capacity of a railway system, capacity consuming events like failures within a railway network should be kept to a minimum. This could be achieved by the use of existing and new condition monitoring systems which can detect, report and predict failure events in an early stage. Demands for higher service quality, higher capacity, network availability and track quality together with less human intervention on tracks, drive the development of railway condition monitoring systems.Failure driven capacity consumption due to worn or defected rolling stock wheels have a big impact on the capacity and the infrastructure condition. Wheel defects such as out-of-round wheels, generates high forces, and could result in large capacity consumption especially for areas with cold climate conditions. Bad wheels cause even higher track wear that reduce the life length of the track. Wheels with fatigue defects could also influence the track safety issues. This paper presents how different wheel defects can be monitored; together with a review of the most common wayside condition monitoring systems on the Swedish railway network. The study also describes how the decision making process could take advantage of the condition monitoring data in order to increase the achieved network capacity.
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| 12. |
- Asplund, Matthias, et al.
(author)
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Data quality assessment of automatic wheel profile measurement systems
- 2016
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In: Current Trends in Reliability, Availability, Maintainability and Safety. - Cham : Encyclopedia of Global Archaeology/Springer Verlag. - 9783319235967 - 9783319235974 ; , s. 717-738
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Conference paper (peer-reviewed)abstract
- The aim of this paper is to present a method for the quality assessment of data from a condition monitoring system for rolling stock wheels to ascertain if the data have the right quality to be used for further analyses. This quality assessment will also show if there are variations between different measurement units for the same system, and if there are relations between different wheel parameter measurements, speed and time. The assessment of data is accomplished using the quality dimension freedom of error. There are two different data sources, namely an automatic wheel profile measurement system and a manual wheel profile measurement device. The manual measurements of wheel profiles are used for verifying the accuracy of the automatic wheel profile measurements, which constitute the larger data set. The proposed method for evaluating the data quality is demonstrated using the data from a specific condition monitoring system. The results show some inconsistencies indicating that this system lacks quality in the dimension of freedom of error and that there is need for internal calibration or self-adjustment of the studied system for quality reasons.
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| 13. |
- Asplund, Matthias, et al.
(author)
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Detector response from a defective wheel
- 2024
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In: Wear. - : Elsevier. - 0043-1648 .- 1873-2577. ; 542–543
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Journal article (peer-reviewed)abstract
- This paper deals with field validation of the force response from a defective wheel after normal service. The defective wheel represents a typical defect arising from normal winter operation in a cold climate. The current detector is a typical wheel load impact detector that has been in use for about fifteen years; this type of detector is widely used in the infrastructure. The wheel has defects of up to1.8 mm in depth and an un-roundness of 0.2 mm. The results from this investigation, pertaining to the particular vehicle and wheel defect, show a linear correlation of speed and force response. Each change in speed of 1 km/h changes the force response by about 0.9 kN.
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| 14. |
- Asplund, Matthias, et al.
(author)
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Enhancing the quality of data from a wheel profile measurement system : a proposed approach
- 2015
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Conference paper (peer-reviewed)abstract
- This investigation proposes a method for increasing the quality of data from an automatic condition monitoring system for railway rolling stock wheels, in order to assure the right data quality for further use of the data. The data quality improvement is used to ensure a higher reliability of the data analysis and to propose a new check routine to ensure that the sensors generate the same data for the same sample. A case study on field data shows how the data from different measurement setups differ for three of four measurements and why this check routine is needed. The paper ends with a discussion and conclusions concerning the improvements that are presented.
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| 15. |
- Asplund, Matthias, et al.
(author)
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Evaluation of wheel profile measurements by means of the contact-point function for the wheel-rail interface
- 2018
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In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit. - : Sage Publications. - 0954-4097 .- 2041-3017. ; 232:4, s. 1225-1239
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Journal article (peer-reviewed)abstract
- This study examines the accuracy of a wayside train wheel profile measurement system. This was accomplished by an evaluation of the contact-point function for the wheel–rail interface. The wheel profile measurement system in question generates data about the wheel profiles of passing trains. These data are used for improving the wheel maintenance procedures for the rolling stock operator. Recent work shows that there are differences between the data from the two different units in the system, but how this influences further use of the data, e.g. in wheel–rail contact analysis, has not been investigated so far. Accordingly, this article shows how two key wheel measures (the wheel flange thickness and the wheel profile) impact on the contact-point function and which of these measures has the largest impact on the contact-point function. The data used in this study were generated by two different measurement units for the same wheel and with the same wheel status. The results show that the different units produce different results and that these differences are more prominent when a difference in the flange thickness is detected, with a resulting shift of the front side of the flange and of the tread. With no difference in the flange thickness, i.e. no shift of the front side of the flange and of the tread, a difference was still detected in the contact conditions. Furthermore, this investigation shows that the shape of the tread has a greater impact on the contact-point conditions compared to a change in the flange thickness of up to 2.5 mm. This difference in the tread shape could have originated in measurement noise or different wheel measurement positions. The results of the study also show the importance of managing the measurement quality before using the data, for example for maintenance decisions.
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| 16. |
- Asplund, Matthias, et al.
(author)
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Field Validation of Force Response from Defective Wheel
- 2022
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In: CM 2022 - 12th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems, Conference Proceedings. - : International Conference on Contact Mechanics of Wheel / Rail Systems. ; , s. 444-448
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Conference paper (other academic/artistic)
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| 17. |
- Asplund, Matthias, et al.
(author)
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Improved wheel-rail system of Sweden’s iron ore line
- 2017
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In: Proceedings of the 11th International Heavy Haul Association Conference (IHHA 2017), Cape Town, South Africa, 2–6 September 2017. - 9780911382662 ; , s. 759-766
-
Conference paper (other academic/artistic)abstract
- ABSTRACT: The Swedish Iron Ore Line (IOL) is the only heavy haul line in Europe. The northern part of the line is located above the Arctic Circle, a very harsh climate. Because of the introduction of new vehicles with a 30-tonnes axle load, the track were gradually replaced between 2006 and 2009 with heavier rails, mostly with a steel grade of R350LHT. Just after the first replacement of track in 2006, the project presented herein was established with the primary goal of improving the life length of the rail, and monitoring activities started. This project now has a unique database of rail degradation data. So far, the information has been used to improve the performance of the wheel-rail system and thus extend the life length of the rail, as well as to improve our knowledge of heavy haul operations in a cold climate. The paper discusses the project progress in general and gives some examples of improvements that have been successfully implemented, such as new rail profiles and a higher grinding frequency. Finally, it discusses the challenges of future capacity improvements, such as an increase in the axle load, and how these can be addressed.
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| 18. |
- Asplund, Matthias, et al.
(author)
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Inspection of railway turnouts using camera
- 2013
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Conference paper (peer-reviewed)abstract
- The railway turnout is an essential component in a railway system, used to divert traffic along different tracks. A turnout includes a number of different parts, including the switch blade, frog, point machine, switch roller, soleplate, check rail, wing rail, drive rods, control rods and other bars. These parts must be kept in good condition, meeting functional and safety requirements. Failing to comply will result in a reduction of the network’s capacity with economic consequences. Not honouring the safety limits could result in severe accidents, including derailment, causing human casualties. By performing the right type of inspection and/or maintenance at the right time, these unwanted events can be reduced. To determine if and when a maintenance action should be performed, the condition of the turnout must be established, usually by manual inspections or with measurement vehicles. The drawback is the discrete nature of these inspection events. Failure modes with development times shorter than the inspection interval could result in a malfunction of the unit. An on-line measurement system would be able to deal with these failure events and initiate correct maintenance actions at an earlier stage. With an on-line system, remotely located turnouts could be inspected without on-site personnel. Capacity consuming failures of turnouts with a strategic location or with bottleneck characteristics could also be corrected before they affect traffic. This paper describes a feasibility study of a camera based inspection system for turnouts and discusses the effect the method could have on system reliability and capacity.
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| 19. |
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| 20. |
- Asplund, Matthias, et al.
(author)
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Reliability and measurement accuracy of a condition monitoring system in an extreme climate : a case study of automatic laser scanning of wheel profiles
- 2014
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In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit. - : SAGE Publications. - 0954-4097 .- 2041-3017. ; 228:6, s. 695-704
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Journal article (peer-reviewed)abstract
- The Iron Ore Line (Malmbanan) is a 473 km long track section located in northern Sweden and has been in operation since 1903. This track section stretches through two countries, namely Sweden and Norway, and the main part of the track runs on the Swedish side, where the owner is the Swedish Government and the infrastructure manager is Trafikverket (the Swedish Transport Administration). The ore trains are owned and managed by the freight operator and mining company LKAB. Due to the high axle load exerted by transportation of the iron ore, 30 tonnes, and the high demand for a constant flow of ore and pellets, the track and wagons must be monitored and maintained on a regular basis. The condition of the wagon wheel is one of the most important aspects in this connection, and here the wheel profile plays an important role. For this reason an automatic laser-based wheel profile monitoring system (WPMS) has been installed on this line using a system lifecycle approach that is based on the reliability, availability, maintainability and safety (RAMS) approach for railways. The system was prepared and installed and is being operated in a collaborative project between the freight operator and infrastructure manager. The measurements are used to diagnose the condition of the wheels, and to further optimize their maintenance. This paper presents a study of the concepts and ideas of the WPMS, and the selection, installation and validation of the equipment using a system lifecycle approach that is based on RAMS for railways. Results from the profile measurements and validation are shown. The system’s reliability during performance in extreme climate conditions, with severe cold and large quantities of snow, is presented. Then the benefits, perceived challenges and acquired knowledge of the system are discussed, and an improved V-model for the lifecycle approach is presented.
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| 21. |
- Asplund, Matthias, et al.
(author)
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Slutrapport avseende hjulprofilmätare i Sunderbyn
- 2014
-
Reports (other academic/artistic)abstract
- Bakgrunden till projektets genomförande har varit den ökande mängden rälsbyten och mängden trafik med 30 tons axellast på Malmbanan. Spårunderhållet och hjulunderhållet har idag de överlägset högsta underhållskostnaderna av järnvägens olika system. Hjulprofilmätaren sågs som en möjlighet att kunna plocka ut de hjul som närmade sig underhållsgränserna för slitage, och därigenom kunna styra underhållet mer kostnadseffektivt.LKAB och Trafikverket enades därför att sätta upp ett gemensamt projekt där en ny typ av mätutrustning utprovades. För att få stöd med datalagring, bearbetning av data mm anlitades LTU och eMaintenanceLAB. Syftet med projektet har varit att undersöka och verifiera att en utrustning för automatisk hjulprofilmätning kan klara av att registrera och larma vid hjulpassager som avviker från de säkerhetsgränser och underhållsgränser som definieras i projektet med hänsyn till vårt klimat och våra förhållanden på Malmbanan. Den bärande idén i detta projekt har varit att man genom en kontinuerlig mätning av hjulprofiler ska kunna ta ut fordon ur trafik innan den avvikande hjulprofilen ger upphov till ett accelererande hjul- och rälslitage och därigenom sänka underhållskostnaden och öka livslängden på både hjul och räl. Projektet har även lett till en högre säkerhet på spåret då man kan mäta hjul som passerat säkerhetsgränsen för hjulparametrar och plockar bort dem, detta var inte var möjligt tidigare. De slutsatser som kan dras från detta projekt är följande:• Utvecklingsprojekt kan med fördel genomföras gemensamt mellan industri, infrastrukturförvaltare och akademi. • För att säkerställa ett bra resultat är det viktigt att genomföra alla steg i ett projekt från koncept till överlämnande. Som stöd för detta har V-modellen används som representerar livscykeln för systemet enligt EN-50126.• Val av tekniklösning och leverantör har gjorts utifrån tekniknivå, referensanläggningar samt drift- och supportmöjlighet och inte enbart utifrån pris. Ett utvecklingsprojekt likt detta handlar inte primärt om att få en utrustning i drift utan överföring av ”know how” kring vilka möjligheter och begränsningar det finns med denna teknik.• Resursbehovet för test och utvärdering underskattades och gjorde att projektet försenades ett år jämfört med ursprunglig tidplan. • Informationen som genereras från denna utrustning är mycket användbar för alla parter som arbetar med utveckling av underhåll inom järnvägen. • Utmaningen för att tillgodogöra sig nyttan från mätstationen ligger i att kunna förädla och integrera de genererade tillståndsdata till respektive underhållsorganisation.
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| 22. |
- Asplund, Matthias, et al.
(author)
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The wheel profile measurement system at Sunderbyn, Sweden : final report
- 2014
-
Reports (other academic/artistic)abstract
- The background to the realisation of this project comprises an increasing number of rail replacements and an increasing volume of traffic with a 30-tonne axle load on the Swedish Iron Ore Line (IOL). When comparing the maintenance costs of all the different systems in the Swedish railway network, the maintenance costs for the track and wheels are by far the highest at present. The wheel profile measurement system (WPMS) was considered to provide the possibility of picking out wheels approaching the maintenance limits for wear and thereby of controlling maintenance in a more cost-effective way. Accordingly, LKAB and Trafikverket (the Swedish Transport Administration) reached an agreement concerning the initiation of a joint project in which a new type of measurement equipment would be tested. To obtain assistance with data storage and processing, etc., Luleå University of Technology (LTU) and its eMaintenance Lab were engaged in the project. The objective of the project has been to investigate and verify whether equipment for automatic wheel profile measurement is capable of registering wheel data and sending alerts concerning the passage of wheels which deviate from the safety and maintenance limits defined in the project, with regard to the climate and conditions prevailing along the Swedish IOL. The fundamental idea behind this project has been that, through continuous measurement of wheel profiles, one should be able to take vehicles out of service before any deviating wheel profiles give rise to accelerating wheel and rail wear, and that one should thereby be able to reduce the maintenance costs and increase the operational life of both wheels and rails. An additional result of the project has been increased safety on the track, since it is possible to measure wheels that have exceeded the safety limit for wheel parameters and remove them, which was impossible previously. The following conclusions can be drawn from this project.• There are benefits to be derived from development projects conducted jointly between industry, infrastructure managers and academia. • In order to ensure good results, it is important to perform all the steps in a project, from the concept phase to the handing-over phase. In support of this, the V-model was used, which represents the life cycle of the system according to EN 50126. • The selection of a technical solution and a supplier was made on the basis of the technology level, reference installations, and operation and support possibilities, and not merely based on the price. A development project of this nature is not primarily a question of putting equipment into operation, but of transferring knowhow concerning the possibilities and limitations associated with the technology in question. • The resource requirement for testing and evaluation was underestimated, which resulted in the project being delayed by one year compared with the original timetable. • The information generated by the equipment installed is very useful for all parties working with the development of railway maintenance. • The challenge with regard to utilising the benefits afforded by the measurement station at Sunderby lies in the ability to process the generated condition data for the maintenance organisations concerned and integrate these data in the operations of these organisations.
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| 23. |
- Asplund, Matthias, et al.
(author)
-
Towards perfected rail maintenance : combining routine and long-term research activities
- 2015
-
Conference paper (peer-reviewed)abstract
- In 2007 the new grinding strategy with “Malmbanan”, Europe’s only heavy-haul railway, has been presented at the IHHA-conference in Kiruna. Four years later an update was given, as in between some adaptations concerning the target profiles and the metal removal requirements have been introduced. The monitoring process on selected test sections using MiniProf- and Eddy-current devices never stopped and provided since valuable understanding of the effect of applying optimized specifications. This was particular important in view of the increasing traffic load and the hence required doubling of the yearly grinding campaigns. The combination of the once fixed routine grinding operations with the research activities resulted in a consistently good rail surface situation and revealed further insight in the complex matter of wheel-rail interaction. The latest findings and further development is presented in this article.
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| 24. |
- Asplund, Matthias
(author)
-
Wayside Condition Monitoring System for Railway Wheel Profiles : Applications and Performance Assessment
- 2016
-
Doctoral thesis (other academic/artistic)abstract
- The railway is an important mode of transport, due to its environmental friendliness, high safety level, and low energy consumption combined with a high transport capacity, among other factors. The Swedish railway network is old, there has been almost no expansion of the network during the past few decades, and more traffic is expected. Therefore, there is currently a demand for more track capacity and, in the short term, the existing network is expected to deliver the increased capacity. The railway operators in the network have a large impact on train delays, and wheel failures are one large contributor of delays. Delays destroy capacity and, therefore, capacityconsuming failures, such as abnormal wheels, need to be minimised. This can be achieved by using appropriate condition monitoring for the wheels on the track to find potential capacity consumers before failures happen. Therefore, the condition of the wheel-rail interface is important, since the state of the wheel influences that of the rail and vice versa. The monitoring of rail profiles is already being performed, but the monitoring of wheel profiles is still in the development phase. This thesis treats the applications and performance assessment of a wheel profile measurement system (WPMS), and presents case studies focusing on its system and measurement performance. The proposed applications concern how the information from the WPMS can be integrated with information from other data sources and with physical models to obtain a true current picture of the wheel behaviour. The thesis investigates the measurement performance of the WPMS by using a paired T-test and a number of quality measures, e.g. the reproducibility and repeatability, the precision-to-tolerance ratio and the signal-to-noise ratio. In conclusion, this thesis shows that the WPMS works well with an expected level of reliability in a harsh climate with respect to its measurement and system performance. By combining other data with the data from the WPMS, potentially abnormal wheels can be found in an early stage if the proposed new maintenance limit for the wheel parameter of the flange height is implemented. Furthermore, through adding a physical model to the process, the real contact condition of the actual wheel-rail interface can be evaluated and measurement deviations can be found. However, the wheel parameters, as well as the entire profile, need a high measurement quality with little variation, which seems to be an issue with respect to the measurement performance when advanced calculations are to be done. Therefore, a new approach for evaluating measurement performance has been developed using established statistical tools and quality measures with predefined acceptance limits; with the help of this approach, one can differentiate between the variation in the measurements originating in the different measurement units and the variation originating in the wheels. This new approach can be applied to judge the measurement performance of wheel profile condition-monitoring systems, and can also be implemented for other condition-monitoring systems to evaluate their measurement performance. Finally, this approach promotes the development of a condition-based maintenance policy by providing more reliable information for maintenance decision makers.
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| 25. |
- Asplund, Matthias
(author)
-
Wayside Condition Monitoring Technologies for Railway Systems
- 2014
-
Licentiate thesis (other academic/artistic)abstract
- The railway is an important mode of transport, due to its environmental friendliness, high safety level, and low energy consumption, among other reasons. Railways provide a sustainable means of transporting a large amount of freight and passengers, in a cost-effective and comfortable way. The railway system has a large number of stakeholders and a small improvement in the system will give many advantages, including financial savings and an increase in the quality of service. The Swedish railway network is old and there has been almost no expansion of the network during the past few decades. There is currently a demand for more track capacity and there are no more tracks availably at the network; therefore, the existing network is expected to deliver more capacity.The railway operators are the largest cause of train delays and wheel failures are one major contributor of the delays caused by operators. The infrastructure manager is the second largest owner of train delays, and a large contributor of their train delays is switches and crossings (S&Cs). This thesis shows proposals for how condition monitoring technology can be used more efficiently for both the infrastructure and the rolling stock to increase the reliability of their critical items by decreasing train delay. Firstly, the condition of the wheel-rail interface is important, in that a bad wheel influences the rail and vice versa. The monitoring of rail profiles is already in use, but the monitoring of wheel profiles is still in the development phase. This thesis shows the performance of a wheel profile measurement system (WPMS) for an extreme climate, and a case study of performance measures such as the accuracy and reliability of the system is presented. An additional topic dealt with is how the information from the WPMS can be combined with that from the wheel defect detectors to find early indications of wheels with bad behaviour. Secondly, the S&C is an essential component of a railway system in that it increases the flexibility by diverting traffic, but S&Cs need adequate support to work properly. A camera-monitoring method for S&Cs is presented which increases the inspection frequency and decreases the human activities on the track and the train delay. In conclusion, this thesis shows that the WPMS investigated works well with a high level of performance concerning measurement accuracy and reliability in an extreme climate, and that there is still some potential for improving the system. The combination of the WPMS and wheel defect detectors shows that wheels with a high flange height have a higher probability of ending up as wheels suffering from failures. A new maintenance limit for the flange height can reduce the number of wheel defects on the track. Camera-monitoring of the S&C will increase the availability and reliability of this item and even reduce the time on the track required for the maintenance action “check” through fewer inspections and maintenance actions. These proposed monitoring techniques can improve the railway system reliability by reducing the consequential train delay times, by decreasing the number of failures of wheels and S&Cs.
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| 26. |
- Blidberg, Karin, et al.
(author)
-
LOWNOISEPAD : Low cost noise control by optimised rail pad
- 2024
-
In: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 324-324
-
Conference paper (other academic/artistic)abstract
- Trafikverket har i samarbete med UIC (Internatinella järnvägsunionen) och Luleå Tekniska Universitet medverkat i projektet LOWNOISEPAD. Syftet är att utveckla mellanlägg (pads) som är optimerade ur bullersynpunkt, utan att andra tekniskt viktiga egenskaper försämras. Slutrapport från UIC och mätrapporter från LTU förväntas bli klara under hösten 2023. Projektet har bestått av sex arbetspaketWP1: Preparation of proceduresWP2: Analysis of the current situationWP3: Selection of the rail pads to be testedWP4: Test site selection and rail pad installationWP5: MeasurementsWP6: Data processing and dissemination och genomförts parallellt med samma metod på järnvägen i tolv Europeiska länder.I projektet påvisas möjliga källbullerreduktioner på 1-5 dBA. De dynamiska egenskaperna på mellanlägg (gummiplattor mellan betongslipers och räl) påverkar bulleremissionerna från järnväg och det är tekniskt möjligt att minska bullret från järnvägen genom att förändra dessa egenskapskrav.
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| 27. |
- El-khoury, Jad, 1975-, et al.
(author)
-
A Roadmap Towards Integrated CPS Development Environments
- 2013
-
Conference paper (peer-reviewed)abstract
- Cyber Physical System (CPS) development is highly heterogeneous, involving many stakeholders, each of which interacts with its development artifacts through a variety of tools, and within several engineering processes. Successful CPS development requires these tools to be well-integrated into a Development Environment (DE) in order to support its many stakeholders and processes. In this paper we identify the main challenges facing DE development for CPSs, and presents a roadmap to meet these challenges. We here take the position that focus should be redirected from trying to achieve a single, one-size-fits-all solution to such a heterogeneous problem. Instead, focus should be placed on supporting the development of highly-customized DEs, which readily can be applied to industrial development. Such a highly-customized DE should fit the needs of a particular development organization, while at the same time taking advantage of relevant standardization efforts.
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| 28. |
- Eriksson, Olle, 1967-, et al.
(author)
-
Statistical analysis of curve squeal based on long-term onboard noise measurements
- 2022
-
Conference paper (other academic/artistic)abstract
- Curve squeal with large magnitude tonal components in the frequency range up to 10 kHz is a cause of annoyance without any satisfying solution. This might be partly due to the gaps in the current understanding of the phenomenon within the research community (e.g. the open question whether the fundamental excitation mechanism is due to “falling friction” or “modal coupling”). Rail-bound traffic is expected to become a backbone in the future sustainable public transportation system. This makes it urgent to increase the state of knowledge in order to develop effective mitigation measures against the problem.Noise recorded by an onboard monitoring system during one year of traffic on the Stockholm metro is studied. The influence of selected variables on the generation of curve squeal is investigated in a statistical assessment. The influence of curve radius on curve squeal probability is estimated by calculating the quotient of squealing samples with respect to the total number of samples captured in circular curve sections. Vehicle speed (operative conditions) is modelled by the introduction of a classification representing different speed profiles (e.g. constant, linear acceleration or deacceleration, etc.). Environmental conditions are accounted for by using humidity and air temperature as predictor variables.A general trend of increased probability of curve squeal for decreasing curve radius is observed. Several subsequent regression analyses could not find a consistent influence of air temperature and humidity on the occurrence of curve squeal. Moreover, preliminary results indicate the existence of a vehicle speed for which a curve is particularly prone to generate squeal noise.
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| 29. |
- Eriksson, Olle, 1967-, et al.
(author)
-
Survey of Curve Squeal Occurrence for an Entire Metro System
- 2024
-
In: Noise and Vibration Mitigation for Rail Transportation Systems. - : Springer. - 9789819978519 - 9789819978526 ; , s. 483-490
-
Book chapter (peer-reviewed)abstract
- The current work presents a statistical analysis based on data collected during approximately 1.5 years of regular operation by two vehicles equipped with an on-board noise monitoring system on the Stockholm metro. Data covers 379,776 passages through 143 curves with radii up to 1000 m. Binary logistic regression is used to investigate the importance of curve radius, vehicle speed, relative humidity, air temperature, rail grinding and vehicle individual on curve squeal. Curve squeal occurrence shows an inverse proportionality with respect to curve radius. This trend is particularly pronounced for curve radii below 600 m. The two vehicles accounted for in the study show differences in propensity to generate squeal. The influence of temperature and relative humidity, and their interaction, on curve squeal is described by an estimated response surface. Results show the occurrence of curve squeal to increase after rail grinding. No strong relationship between curve squeal occurrence and vehicle speed is identified.
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| 30. |
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| 31. |
- Famurewa, Stephen Mayowa, et al.
(author)
-
Analysis of gauge widening phenomenon on heavy haul line using measurement data
- 2014
-
In: Proceedings of the 3rd international workshop and congress on eMaintenance. - Luleå : Luleå tekniska universitet. - 9789174399721 - 9789174399738 ; , s. 9-15
-
Conference paper (peer-reviewed)abstract
- The operational safety and maintenance cost of railway transportare largely influenced by the geometric characteristics of thetrack. One of the major geometric parameters essential for safeand high performance of railway track is the gauge. Thephenomenon of gauge widening is the gradual increase of thegauge size and it is one of the major track failure modes that couldcause derailments if it is not effectively restored in due time.Excessive gauge widening is as a result of inadequate lateral trackresistance and lateral rail strength capacity as influenced bysleeper, fastener ballast or subgrade conditions. This paperpresents an exploratory analysis of gauge measurement data tosummarize the main characteristics and explain the progression ofgauge widening in different curve types. The measurement datawere collected from 2007 to 2013 in curves with different layoutsand structures. The growth of gauge over time is analysed andalso the variation in the gauge dimension with the layout of thetrack is presented for engineering considerations. Apparently,gauges of all the curves studied are above the nominal dimensionof 1435mm but below the immediate action limit. The resultshows that curve radius has significant effect on the rate of gaugewidening as it has been shown that tight curves A and B have highrates of deterioration while curves D and E with large radius haverelatively low rates of deterioration. A practical application of thisstudy is the use of the presented quality assessment procedure andthe estimated gauge widening rate for condition evaluation andmaintenance planning.
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| 32. |
- Famurewa, Stephen Mayowa, et al.
(author)
-
Composite indicator for railway infrastructure management
- 2013
-
Conference paper (peer-reviewed)abstract
- The assessment of efficiency and effectiveness of past maintenance decisions and actions is an essential element in maintenance process. The significance of this is not only limited to communicating the value contribution of maintenance to overall business objectives but also to drive maintenance for improvement and towards excellence. However the existence of numerous maintenance result areas and many operational level indicators often lead to distributed information that is not in a suitable format required to support decision making. This paper motivates the use of fuzzy logic approach to aggregate selected indicators to appreciate the information bit distributed in each indicator. The selected indicators include measures related to safety, comfort, punctuality, availability and reliability aspects of maintenance. Linguistic description and fuzzy sets are developed for each of the indicators which are regarded as input parameters. Also domain experts are employed to develop inference rules for the aggregation process. The methodology of using fuzzy inference system for aggregating maintenance performance indicators is demonstrated with selected line sections of Trafikverket (Swedish Transport Administration). The resulting composite indicator gives a reliable quantification of the health condition of the asset and performance of maintenance within the period under consideration. This can be easily communicated and benchmarked within the organization of the infrastructure manager.
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| 33. |
- Famurewa, Stephen Mayowa, et al.
(author)
-
Composite indicator for railway infrastructure management
- 2014
-
In: Journal of Modern Transportation. - : Springer Science and Business Media LLC. - 2095-087X .- 2196-0577. ; 22:4, s. 214-224
-
Journal article (peer-reviewed)abstract
- The assessment and analysis of railway infrastructure capacity is an essential task in railway infrastructure management carried out to meet the required quality and capacity demand of railway transport. For sustainable and dependable infrastructure management, it is important to assess railway capacity limitation from the point of view of infrastructure performance. However, the existence of numerous performance indicators often leads to diffused information that is not in a format suitable to support decision making. In this paper, we demonstrated the use of fuzzy inference system for aggregating selected railway infrastructure performance indicators to relate maintenance function to capacity situation. The selected indicators consider the safety, comfort, punctuality and reliability aspects of railway infrastructure performance. The resulting composite indicator gives a reliable quantification of the health condition or integrity of railway lines. A case study of the assessment of overall infrastructure performance which is an indication of capacity limitation is presented using indicator data between 2010 and 2012 for five lines on the network of Trafikverket (Swedish Transport Administration). The results are presented using customised performance dashboard for enhanced visualisation, quick understanding and relevant comparison of infrastructure conditions for strategic management. This gives additional information on capacity status and limitation from maintenance management perspective.
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| 34. |
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| 35. |
- Famurewa, Stephen Mayowa, et al.
(author)
-
Evaluation of rail wear characteristics on heavy haul track section using measurement data
- 2015
-
Conference paper (peer-reviewed)abstract
- The rail is a structural component of track that serves as the running surface, guiding element, load carrier and distributor. The wear of rail is of great interest since it is known to be an important degradation mode that can limit the performance of rail, reduce its life span and significantly increase the life cycle cost of track if not well managed. It is therefore pertinent to study the wear behaviour of rail under increased loading condition and adopted grinding strategy. In this paper, the analysis of rail profile measurement data collected between 2008 and 2013 has been carried out. This is used to evaluate the wear characteristics of curves with different radii on the Swedish iron ore line to provide engineering insight for improving maintenance for better rail performance. The result shows that the average natural wear rate on sharp curves is about 2 times the wear rate on the mild curves and 5 times the wear rate on the tangent tracks. In addition, the typical total wear on sharp curves after 6 years is over 250 mm2 which is about 1½ and 2½ times the wear on mild curves and tangent tracks respectively
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| 36. |
- Famurewa, Stephen Mayowa, et al.
(author)
-
Framework for performance based maintenance contracting
- 2012
-
Conference paper (other academic/artistic)abstract
- The achievement of maintenance objectives is the pursuit of any maintenance department, as this will support the achievement of the overall business objectives. Using in-house or outsourced maintenance service provider is a decision which poses challenge to a lot of organisations. Should the decision be for outsourcing, the next concern is the selection of the most appropriate strategy suitable for the business environment, structure and philosophy. This article gives a detailed description of innovative maintenance contracting strategy namely performance based maintenance contracting. We have presented a structured framework as well as a monitoring tool for the mentioned outsourcing strategy to facilitate easy implementation.
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| 37. |
- Famurewa, Stephen Mayowa, et al.
(author)
-
Implementation of performance based maintenance contracting in railway industries
- 2013
-
In: International Journal of Systems Assurance Engineering and Management. - : Springer Science and Business Media LLC. - 0975-6809 .- 0976-4348. ; 4:3, s. 231-240
-
Journal article (peer-reviewed)abstract
- The achievement of maintenance objectives to support the overall business objectives is the pursuit of any maintenance department. Using in-house or outsourced maintenance service provider is a decision which poses challenge in the management of maintenance function. Should the decision be for outsourcing, the next concern is the selection of the most appropriate strategy suitable for the business environment, structure and philosophy. In an effort to improve maintenance function so as to deliver set objectives, some infrastructure managers (IM) adopted the approach of outsourcing maintenance function, giving larger responsibilities to maintenance service providers called contractors. Moreover, such change requires adequate attention to meet the pressing need of achieving the designed capacity of the existing railway infrastructure and also support a competitive and sustainable transport system. This paper discusses performance based railway infrastructure maintenance contracting with its issues and challenges. The approach of this article is review of literature and as well as synthesis of practices. A framework to facilitate the successful implementation of Performance Based Railway Infrastructure Maintenance (PBRIM) is presented. Also a performance monitoring system is proposed to assess the outcome and identify improvement potentials of the maintenance outsourcing strategy. A case study is given to demonstrate the monitoring of a typical maintenance activity that can be outsourced using this outsourcing strategy.
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| 38. |
- Famurewa, Stephen Mayowa, et al.
(author)
-
Maintenance analysis for continuous improvement of railway infrastructure performance
- 2015
-
In: Structure and Infrastructure Engineering. - : Informa UK Limited. - 1573-2479 .- 1744-8980. ; 11:7, s. 957-969
-
Journal article (peer-reviewed)abstract
- Railway transport system is massive and complex, and as such it requires effective maintenance to achieve the business goal of safe, economic and sustainable transportation of passengers and goods. The growing demand for improved service quality and capacity target by railway infrastructure managers requires appropriate maintenance analysis to facilitate continuous improvement of infrastructure performance. This paper presents the application of risk matrix as a maintenance analysis method for the identification of track zones that are bottlenecks that limit operational capacity and quality. Furthermore, an adapted analysis method is proposed to create a hierarchical improvement list for addressing the problem of train mission interruption and reduced operational capacity. A case study of a line section of the Swedish network is presented. The result classifies the zones on the line section into different risk categories based on their contribution to loss of capacity and punctuality. In addition, an improvement list for the lower-level system is presented to facilitate maintenance decisions and continuous improvement at both operational and strategic levels.
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| 39. |
- Famurewa, Stephen Mayowa, et al.
(author)
-
Maintenance analytics for railway infrastructure decision support
- 2017
-
In: Journal of Quality in Maintenance Engineering. - : Emerald Group Publishing Limited. - 1355-2511 .- 1758-7832. ; 23:3, s. 310-325
-
Journal article (peer-reviewed)abstract
- PurposeThis purpose of this article is to present a framework for maintenance analytics that is useful for the assessment of rail condition and for maintenance decision support. The framework covers three essential maintenance aspects: diagnostic, prediction and prescription. The article also presents principal component analysis (PCA) and local outlier factor (LOF) methods for detecting anomalous rail wear occurrences using field measurement data.Design/methodology/approachThe approach used in this paper includes a review of the concept of analytics and appropriate adaptation to railway infrastructure maintenance. The diagnotics aspect of the proposed framework is demonstrated with a case study using historical rail profile data collected between 2007 and 2016 for 9 sharp curves on the heavy haul line in Sweden.FindingsThe framework presented for maintenance analytics is suitable for extracting useful information from condition data as required for effective rail maintenance decision support. The findings of the case study include: combination of the two statistics from PCA model (T2 and Q) can help to identify systematic and random variations in rail wear pattern that are beyond normal: the visualisation approach is a better tool for anomaly detection as it categorises wear observations into normal, suspicious and anomalous observations.Practical implicationsA practical implication of this article is that the framework and the diagnostic tool can be considered as an integral part of eMaintenance solution. It can be easily adapted as online or onboard maintenance analytic tool with data from automated vehicle based measurement system.Originality/valueThis research adapts the concept of analytics to railway infrastructure maintenance for enhanced decision making. It proposes a graphical method for combining and visualising different outlier statistics as a reliable anomaly detection tool.
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| 40. |
- Famurewa, Stephen Mayowa, et al.
(author)
-
Maintenance improvement: an opportunity for railway infrastructure capacity enhancement
- 2013
-
Conference paper (peer-reviewed)abstract
- The continually increasing demand on railway service in terms of the quantity and quality of both passenger and freight train operations is the core of the general railway capacity challenge. Moreover, this challenge has been the driver for some improvements in the technical system, traffic operation & management as well as maintenance process, although the room for improvement in the maintenance function is still large. An effective capacity management entails critical study of the three essential capacity parameters: infrastructure, traffic and operating parameters. To further explore the fundamentals of capacity management, this paper investigates some essential issues on railway infrastructure capacity. A review of the general railway infrastructure capacity challenge and management is presented, including some strategic measures to enhance capacity and quality of service of existing infrastructure. We have proposed maintenance improvement framework to explore the opportunity of improving the capacity situation on a network. This framework will facilitate the identification of both critical systems and activities with the largest impact on the capacity and also some root causes for critical system. The framework has suggested methodology to improve allocation and utilisation of track possession time, giving room for capacity expansion of existing railway infrastructure.
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| 41. |
- Famurewa, Stephen Mayowa, et al.
(author)
-
Railway Maintenance Performance : Perspective for Improvement
- 2012
-
Conference paper (other academic/artistic)abstract
- Railway transport system is complex and requires effective maintenance to achieve the business goal of safe, economic and sustainable transportation of passengers and goods. The maintenance service either provided by internal or external agents is anticipated to reach specified objectives. The major objective of maintenance is to assure dependable infrastructure with the available resources, to meet operational target and other business objectives of infrastructure manager. This however requires continuous improvement through effective performance measurement and management. This article has identified some salient criteria or perspective of maintenance process that are essential to quantify the impact of past maintenance decisions and actions. The challenges of developing and implementing maintenance performance system in the railway industries are discussed. A synthesised system of maintenance performance measurement is also suggested, this emphasises the important performance aspects. A case study of a line section on the heavy haul line with mixed traffic, belonging to the Swedish railway network is presented as well to demonstrate the analytical perspective of performance indicators. This will enhance the identification of improvement opportunities in railway infrastructure maintenance. Such improvements will support the overall business goal of meeting service quality and capacity target of infrastructure manager.
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| 42. |
- Garmabaki, Amir H. Soleimani, et al.
(author)
-
A Survey on Underground Pipelines and Railway Infrastructure at Cross-Sections
- 2019
-
In: Proceedings of the 29th European Safety and Reliability Conference (ESREL 2019). - Singapore : Research Publishing Services. ; , s. 1094-1101
-
Conference paper (peer-reviewed)abstract
- Underground pipelines are an essential part of the transportation infrastructure. The structural deterioration of pipelines crossing railways and their subsequent failures are critical for society and industry resulting in direct and indirect costs for all the related stakeholders. Pipeline failures are complex processes, which are affected by many factors, both static (e.g., pipe material, size, age, and soil type) and dynamic (e.g., traffic load, pressure zone changes, and environmental impacts). These failures have serious impacts on public due to safety, disruption of traffic, inconvenience to society, environmental impacts and shortage of resources. Therefore, continuous and accurate condition assessment is critical for the effective management and maintenance of pipeline networks within transportation infrastructure. The aim of this study is to identify failure modes and consequences related to the crossing of pipelines in railway corridors. Expert opinion have been collected through two set of questionnaires which have been distributed to the 291 municipalities in the whole Sweden. The failure analysis revealed that pipe deformation has higher impact followed by pipe rupture at cross-section with railway infrastructure. For underground pipeline under railway infrastructure, aging and external load gets higher ranks among different potential failure causes to the pipeline.
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| 43. |
|
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| 44. |
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| 45. |
|
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| 46. |
|
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| 47. |
- Korchynska, Solomiia, et al.
(author)
-
Life-long impairment of glucose homeostasis upon prenatal exposure to psychostimulants
- 2020
-
In: EMBO Journal. - : EMBO. - 1460-2075 .- 0261-4189. ; 39:1
-
Journal article (peer-reviewed)abstract
- Maternal drug abuse during pregnancy is a rapidly escalating societal problem. Psychostimulants, including amphetamine, cocaine, and methamphetamine, are amongst the illicit drugs most commonly consumed by pregnant women. Neuropharmacology concepts posit that psychostimulants affect monoamine signaling in the nervous system by their affinities to neurotransmitter reuptake and vesicular transporters to heighten neurotransmitter availability extracellularly. Exacerbated dopamine signaling is particularly considered as a key determinant of psychostimulant action. Much less is known about possible adverse effects of these drugs on peripheral organs, and if in utero exposure induces lifelong pathologies. Here, we addressed this question by combining human RNA-seq data with cellular and mouse models of neuroendocrine development. We show that episodic maternal exposure to psychostimulants during pregnancy coincident with the intrauterine specification of pancreatic β cells permanently impairs their ability of insulin production, leading to glucose intolerance in adult female but not male offspring. We link psychostimulant action specifically to serotonin signaling and implicate the sex-specific epigenetic reprogramming of serotonin-related gene regulatory networks upstream from the transcription factor Pet1/Fev as determinants of reduced insulin production.
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| 48. |
- Lemma, Yonas, et al.
(author)
-
Investigation of the Top-of-Rail Friction by Field Measurements on Swedish Iron Ore Line
- 2015
-
In: International Journal of COMADEM. - 1363-7681. ; 18:2, s. 17-20
-
Journal article (peer-reviewed)abstract
- Friction management in the railway industry is a well-established technology with the aim of optimizing the friction between the wheel and rail. Determining the friction coefficient (μ) at the wheel-rail interface is therefore important especially for heavy haul lines with higher axle loads. This paper presents an initial study of the top-of-rail friction condition of a line with 30 ton axle load, the Iron Ore Line in the northern part of Sweden. The friction coefficient between the rail and the metal wheel of a portable tribometer was measured at different geographical locations and in different environmental conditions. The effects of precipitation are studied and compared with the effects of top-of-rail friction modifiers.The measurements of non-lubricated line sections showed values of μ≈0.6, compared to μ≈0.3 for areas with, for example, top-of- rail lubrication. In snowy conditions a decrease in friction could also be detected.
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| 49. |
- Lemma, Yonas, et al.
(author)
-
Top-of-Rail Friction Measurements of the Swedish Iron Ore Line
- 2014
-
In: Proceedings of the 3rd international workshop and congress on eMaintenance. - Luleå : Luleå tekniska universitet. - 9789174399721 - 9789174399738 ; , s. 3-7
-
Conference paper (peer-reviewed)abstract
- Friction management in the railway industry is a well-establishedtechnology with the aim of optimizing the friction between wheeland rail. Determining the friction coefficient (Q) at the wheel-railinterface is therefore important especially for heavy haul lineswith higher axel loads. This paper presents an initial study of thetop-of-rail friction condition of a 30 ton axel load, Iron Ore line inthe northern part of Sweden. The friction coefficient between therail and a metal wheel of a portable Tribometer was measured atdifferent geographical locations and during differentenvironmental conditions. The effects of precipitation are studiedand compared with the effects of top of rail friction modifiers. Themeasurements of not lubricated line sections showed valuesaround Q 0.6 compared to Q 0.3 for areas with e.g. top-of- raillubrication. During snowy conditions a decrease in friction couldalso be detected.
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| 50. |
- Lin, Jing, et al.
(author)
-
Analysis for Locomotive Wheels’ Degradation
- 2014
-
In: 2014 proceedings - Annual Reliability and Maintainability Symposium (RAMS 2014). - Piscataway, NJ : IEEE Communications Society. - 9781479928477
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Conference paper (peer-reviewed)abstract
- This paper undertakes a reliability study using both classical and Bayesian semi-parametric frameworks to explore the impact of a locomotive wheel's position on its service lifetime and to predict its other reliability characteristics. The goal is to illustrate how degradation data can be modeled and analyzed by using classical and Bayesian approaches. The adopted data in the case study have been collected from the Swedish company. The results show that: 1) an exponential degradation path is a better choice for the studied locomotive wheels; 2) both classical and Bayesian semi-parametric approaches are useful tools to analysis degradation data; 3) under given operation conditions, the position of the locomotive wheel could influence its reliability
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