Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Introduction <s> Purpose – The purpose of this study is to identify maintenance related losses, and their causes, in order to describe different deviations in the maintenance process that contributes to incidents and accidents at the Swedish Railway.Design/methodology/approach – In this paper incident and accident reports from 666 derailments and collisions at the Swedish Railway during 1988‐2000, stored in a national database, are studied with respect to possible maintenance related causes.Findings – The railway is a complex technical system used for both freight and passenger transportation. Maintenance is one way to achieve safety and dependability of the railway. However, at the same time badly performed maintenance may also cause accidents. The study shows that maintenance related causes represent 30 percent of all rail and track related incidents and accidents represented in the database. About 80 percent of the maintenance related accidents happen during the execution phase. The most common cause of maintenance rel... <s> BIB001 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Introduction <s> The Maintenance Management Frameworkdescribes and reviews the concept, process and framework of modern maintenance management of complex systems; concentrating specifically on modern modelling tools (deterministic and empirical) for maintenance planning and scheduling. It presents a new perspective of maintenance management by: focusing on the course of maintenance actions; presenting a structure that ensures proper support for current maintenance managers; clarifying the functionality that is required from information technology when applied to maintenance and the functions of modern maintenance engineering; and creating a set of practical models for maintenance management planning and scheduling. The discussion of all of these issues is supported through the use of case studies. The Maintenance Management Frameworkwill be beneficial for engineers and professionals involved in: maintenance management, maintenance engineering, operations management, quality, etc. It will also be of interest to graduate students and researchers in this field. <s> BIB002 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Introduction <s> Abstract ACEM–Rail is an ongoing research project supported by the 7th Framework Programme of the European Commission [www.acem–rail.eu]. It aims to improve the railway maintenance by the development of a highly integrated automatic system. It focuses on the track. The final goal is to reduce the costs and the interaction of maintenance operations with railway services as well as to improve the quality, safety, reliability and sustainability of the railway system. The ACEM–Rail project relies in five pillars: i) development of several track inspection technologies (some of them embarked on commercial trains), ii) development of predictive algorithms to estimate track defect evolution, iii) development of optimization algorithms and techniques for the planning of maintenance tasks, iv) development of an efficient and intelligent system to manage all subsystem included in the track and v) development of algorithms and tools to monitor the execution of maintenance tasks. This paper presents ACEM–Rail initial achievements in the first four pillars. <s> BIB003 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Introduction <s> The maintenance of the railway infrastructure is a complex process that represents a significant percentage of total railway infrastructure costs. The state of infrastructure depends on many factors such as the characteristics and age of the elements, the track geometry, topography and geology, weather conditions or supporting loads. Furthermore, the maintenance operations involve the track occupation that requires the planning and coordination of rail activities in order to minimize the disruption of train services. Finally, the maintenance management based on cyclical works and on corrective maintenance entails high costs in both resources reliability and availability of infrastructure. The ability of knowing the conditions of the track and predict their evolution would allow to fit the maintenance management to a model based on conditions/predictions. This will help those responsible for making decisions to achieve optimal maintenance plans that minimize the maintenance costs, ensure a satisfactory safety margin and prevent quick degradation of track quality. ACEM-Rail is a project funded by the European VIIFP for the organization and control of the maintenance of railway infrastructure. The project aims the development of new technologies for the automation of the maintenance management with the goal of reducing costs, time and resources required for maintenance activities and, therefore increasing the availability of infrastructure. ACEM-Rail project is based on five pillars: i) development of several technologies for the automated and cost effective inspection of the track (some of them on-board of commercial trains), ii) development of algorithms for assessing the state of the infrastructure and estimating the evolution of defects, iii) development of optimization algorithms and techniques for planning and scheduling the maintenance tasks in short, mid and long term, iv) development of an effective Infrastructure Management Subsystem that supports the decision-making process and is responsible of the management of the railways maintenance, v) development of technologies and tools for monitoring the proper execution of maintenance tasks. In this paper the authors set the focus on the ACEM-Rail IMS (Infrastructure Management Subsystem). This system is a modular architecture built as a composition the project subsystems (algorithms and data) with software specialized in the management of assets maintenance. The main component of the system is a commercial CMMS (Computerized Maintenance Management System) that implements LAM (linear asset management) that allows the “dynamic segmentation” of the line, permitting to specify attributes and features along the railway lines. This system also allows the definition of “Linear relationships” indicating intersections, parallel or grade crossing of linear assets. In ACEM-Rail, the railway infrastructure is decomposed into track segments that represent the smallest unit to be treated. These assets are characterized with the information required for the automation of management like classification and hierarchy, track composition, geometry, speed, breaking degree, etc. The train services are included into the system in order to provide with information about the operation in the railway network, availability time windows for maintenance and loads over the infrastructure. This database receives automated information about the state of the track and the location of warnings with its corresponding defect type and severity level. The warnings can be generated by the inspection sensors, the maintenance technician or by the preventive maintenance planning. These warnings are managed by the PMU (Process Management Unit) that determines the workflow that is required for maintenance of each problem. The system provides with different workflows depending on the detection system, the defect type, the location and the severity level. A warning may require a visual inspection to determine the type and severity of a defect, can require periodic inspections to have control on the degradation process or may need a corrective maintenance operation. A generic workflow for corrective maintenance consists of the following steps: i) the system estimates the degradation of the defect and calculates the current and future maintenance costs, ii) this information, in combination with the availability of maintenance resources and time, is used by tactical planning algorithms to generate the optimal maintenance plan for the overall railway infrastructure, iii) the system generates automatic work orders to correct the defects that are planned for the next weeks and keeps the rest of warnings until the next tactical planning execution, iv) the system manages the life cycle of work orders until the defect is corrected. <s> BIB004 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Introduction <s> The early detection of faults in rolling stock wheels and axle bearings is of paramount importance for rail infrastructure managers as it contributes to the safety of rail operations. In this paper we report on the key results that have arisen from the development and implementation of a novel condition monitoring system based on high-frequency acoustic emission and vibration analysis installed on a train. The novel system makes use of inexpensive and robust acoustic emission sensors and accelerometers, which can be easily installed on the axle bearing box with minimal intervention required. Experimental work carried out under actual conditions at the Long Marston rail track and on the Lisbon – Cas-Cais suburban line has proven that the developed system is capable of detecting wheel and axle bearing-related defects with various levels of severity. <s> BIB005 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Introduction <s> The ‘Health and Prognostic Assessment of Railway Assets for Predictive Maintenance’ (HPA) project is developing a Prognostic ::: tool, aiming to enhance the existing capability of London Underground escalators’ Remote Condition Monitoring (RCM) ::: system, with the purpose of facilitating change from preventative to predictive maintenance. This paper investigates the ::: organisational challenges associated with the introduction of this tool into the organisation. The paper will describe the approach adopted to model the extant maintenance processes and associated ::: organisational structures which revealed issues to do with unclear processes, poor communication and data sharing links and ::: problems with delineation of responsibility for decision making. It will go on to describe the development of a new maintenance ::: process model that incorporates the additional functionality provided by the newly developed Prognostic Tool, which ::: necessitate changes of roles responsibility, organisational processes and activities. <s> BIB006
Maintenance can be defined as a task or series of tasks that protect or reinstate the anticipated condition of a system, and these tasks include technical, administrative, and managerial actions taken BIB002  . In railway industry, proper maintenance of infrastructure, rolling-stock, and other resources are vital in providing a safer, reliable, efficient, and resilient output. In Swedish railway, about 30% of all rail and track related incidents and accidents that took place between 1988 to 2000 were due to maintenance related causes BIB001 . Additionally, it has been revealed that among 700 accidents reported over 23 countries, 37% were due to rolling-stock faults and 36% were due to failures in infrastructure BIB005 . Further, by referring to Pareto graph in Figure 1a , it can be realized that maintenance contributes to most 80% of the rail and track related accidents in Sweden. In addition, by referring to the Pareto graph in Figure 1b , it is evident that rolling-stock and infrastructure faults contributed almost 80% of accidents summarized by the D-RAIL FP7 project. (a) (b) Figure 1 . (a) Rail and track related incidents and accidents in Swedish railway BIB001 and (b) Railway accidents considered by cause in the D-RAIL FP7 project BIB005 . In addition, railway maintenance tasks are costly, and poor maintenance or failure to conduct Figure 1 . (a) Rail and track related incidents and accidents in Swedish railway BIB001 and (b) Railway accidents considered by cause in the D-RAIL FP7 project BIB005 . In addition, railway maintenance tasks are costly, and poor maintenance or failure to conduct preventive maintenance will lead to expensive consequences BIB006 BIB004 . According to the joint report that was published by the United Kingdom's (UK's) Department for Transport and the Office of Rail Regulation Network, rolling stock maintenance in the country accounted £0.4 bn, which is around 3% of the total railway expenditures in 2009-2010 and a typical rolling-stock maintenance would cost about 44% of its whole life costs  . Based on the report that was published by National Audit Office, UK in 2015, the annual maintenance expenditures of UK's rail infrastructure exceeds £1 bn and in 2013-2014 and more than two-thirds of 25,531 employees in Network Rail, UK were placed on maintenance related jobs  . Further, the maintenance cost in Europe railway ranges from € 30,000 to 100,000 km/year BIB003 . In the UK, it has been suggested that about 20%-30% of the service life maintenance cost of a passenger rolling-stock is associated with wheelset maintenance  . On the other hand, inadequate maintenance will reduce the reliability of services, and this leads to delays, train cancellations, and customer dissatisfactions BIB003 . Based on past data, about 23%, 17%, and 10% of the UK wide train delays were taken place due to rolling-stock faults, track faults, and power/signal faults, respectively-which could have been reduced or avoided by preventive maintenance  .