Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Importance of Robotic and Autonomous Systems (RAS) in Maintenance <s> The present paper reports the results of a questionnaire-based survey of night train operators’ attitudes toward management, operating procedures, and other organisational issues that potentially impact on safety. Responses were collected from all of the operators of track maintenance trains servicing the Japanese high-speed railway (Shinkansen). Two versions of the questionnaire, the TMAQ (Train Management Attitudes Questionnaire), were developed based on Helmreich’s FMAQ (Flight MAQ) and its derivative, the SMAQ (Ship MAQ). The TMAQ and its progenitor seek to elicit respondents’ views of, and attitudes to, a range of safety related factors including morale, motivation, leadership and human relations in their organisation.To identify dimensions of safety culture as elicited through the TMAQ, a principal component analysis was applied to the questionnaire responses of the original TMAQ. The analysis yielded seven attitude factors, including morale and motivation. Of the seven factors, a close correlation was identified between the factor scores representing operators’ morale and motivation and the actual accident/incident rates for each of the five branches belonging to a single-track maintenance company. A branch that employed train operators having relatively higher morale and motivation exhibited a lower accident/incident rate. Furthermore, the very same correlation was also found for company based responses collected from all track maintenance companies working for the high-speed railway.In addition to the branch and company based comparisons for track maintenance train operators, we also compared attitude factors between different groups of operators (drivers and supervisors), and between two different periods surveyed in a two year interval. Finally, we examined differences in terms of attitude factors between track maintenance operators and seafarers surveyed by applying slightly different variants of the same generic form of questionnaire (Helmreich’s SMAQ). Based on these survey results, we discuss potential risk factors for accidents of track maintenance trains and some implications for improving railway safety. <s> BIB001 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Importance of Robotic and Autonomous Systems (RAS) in Maintenance <s> In risk management research, risk-taking is mostly treated as deviation that calls for improved risk communication. I argue, however, that risk-taking should be seen as expressing a rationale of its own; thus, improving safety requires that this rationale be adequately understood and that the conditions that reproduce risk-taking be changed. This argument is supported by an ethnography of railway maintenance in Sweden. Railway technicians are charged with maintaining the railway infrastructure to support safe and punctual trains, an assignment that exposes them to occupational hazards. The technicians' claim of occupational responsibility for transportation safety risks is framed by two notions in occupational discourse: first, the safety-critical nature of their tasks, and second, the notion of service to the general public. Technician interdependence in achieving occupational safety requires mutual responsibility in the team. Technicians justify occupational risk-taking, claiming it is sometimes needed to achieve production goals given the available time and resources and the manageability of the risks taken. Finally, I stress the need for technicians to change their frames of reference and for employers to assume responsibility for reducing the need for risk-taking. <s> BIB002 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Importance of Robotic and Autonomous Systems (RAS) in Maintenance <s> The detection of fastener defects is an important task in railway inspection systems, and it is frequently performed to ensure the safety of train traffic. Traditional inspection is usually operated by trained workers who walk along railway lines to search for potential risks. However, the manual inspection is very slow, costly, and dangerous. This paper proposes an automatic visual inspection system for detecting partially worn and completely missing fasteners using probabilistic topic model. Specifically, our method is able to simultaneously model diverse types of fasteners with different orientations and illumination conditions using unlabeled data. To assess the damages, the test fasteners are compared with the trained models and automatically ranked into three levels based on the likelihood probability. The experimental results demonstrate the effectiveness of this method. <s> BIB003 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Importance of Robotic and Autonomous Systems (RAS) in Maintenance <s> This study examines the economies of scale and the determinants of rolling stock maintenance costs for 24 urban rail transit operators. The estimates reveal significant returns to scale in maintenance for both per car and per car km. The econometric analysis also provides statistically significant cost elasticities for wages and staff hours suggesting substitution effects between factors. Staff outsourcing is found to significantly decrease costs, whereas higher levels of fleet availability at the peak and rolling stock failures increase it. The effect of the age of rolling stock and the network is negligible on rolling stock maintenance costs although the analysis reveals a downward trend in rolling stock costs among the CoMET-Nova metros. <s> BIB004 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Importance of Robotic and Autonomous Systems (RAS) in Maintenance <s> Abstract This paper formulates a control and path planning approach for a Cab Front Cleaning Robot. Currently, the operation of cleaning the front part of a train cab is performed manually under challenging conditions. The aim of this work is to formulate a control and path planning solution for the employment of a robot manipulator for such cleaning activity. The proposed solution comprises the study of the interaction between the robotic manipulator and an unknown surface, and consists in using an Operational Space Formulation implementation of simultaneous force and position control. The end-effector trajectory results from projecting a raster scan onto the surface to be cleaned, in real-time, with path adaptation to local surface geometry nuances. This paper also presents a list of criteria to validate future results. <s> BIB005
Railway companies drive towards continuous improvements of existing infrastructure, fleets, resources, and processes due to increased competition and rapid expansion. For example, it is projected to increase the UK's national rail traffic in passenger miles by 100% over the next 30 years, resulting in an increase of 11,566 rolling-stock fleets in 2046 when compared to 2017  . Therefore, optimizing inspection and repair of the rail network, facilities, and rolling-stocks in a cost-effective manner, whilst preserving or enhancing the safety, quality, and reliability of the service remains a key challenge BIB004 . For instance, Office of Rail and Road, UK expects Network Rail to carry out its maintenance 17% more efficiently by the end of 2019. Further, to reach efficiency targets, the Network Rail plans to reduce its maintenance staff by 8% over the 2014-2019 control period  . In addition, railway maintenance technicians risk own safety to assure the safety of passengers and to keep trains operating. In most occasions, these railway employees perform their jobs in unfavourable and unergonomic environments. For instance, railway track maintenance technicians and engineers that are constantly exposed to severe weather conditions and encounter risks while working on active railway tracks with live power transmission lines/rails in the vicinity, trains travelling at high speeds from adjacent tracks, working at heights, or in unergonomic postures for prolonged periods BIB002 BIB003 . In addition, the workers in rolling-stock maintenance and service within depots face a similar amount of risks. For example, in the UK, the cab front cleaning is manually conducted, which exposes workers to highly dampened environments close to high voltage overhead power lines or electrified third rails BIB005 . Another hazardous rolling stock maintenance task is transmission fluid changing process, where technicians need to execute the bulk of work beneath rolling-stock in unergonomic environments, while getting exposed to hazards, such as oil spill slip/trip risks or working too close to electrified third rails  . Therefore, the introduction of RAS to such dull, dirty, and dangerous maintenance tasks could potentially minimize the health and safety risks on technicians. The majority of railway maintenance tasks are monotonous and possibly depend on attitude and self-discipline of technician towards the job BIB001 . When considering Japanese high-speed railway track maintenance-which involves a train driver and a supervisor who perform well defined simple series of tasks over a prolonged period, where it is easy to lose focus and motivation to accomplish an immaculate job BIB001 . Besides, human errors are inevitable. Such human errors in the railway include disassembly errors, inspection errors, assembly errors, decision-making errors, and installation errors. Human errors can cause disastrous failures, and subsequently the loss of lives  . In contrast, present-day robots and autonomous systems are renowned for their high accuracy and path repeatability. Therefore, railway companies should consider such capabilities and utilize RAS to handle monotonous or non-value-added maintenance tasks and utilize railway technicians to do advanced, challenging, and value-added tasks. Further, it has been revealed that rolling stock maintenance could be clustered and distributed over local contractors. This will encourage them to be specialists in the field, and apply techniques to achieve increased productivity through automation  . Additionally, it has been identified that increased automation is a key objective in the Rail Technical Strategy 2012, and it is expected to obtain operational cost benefits by intelligent maintenance techniques   . Therefore, the introduction of autonomous systems in order to eliminate or minimize human intervention in maintenance processes would be an ideal technique, and it can be viewed that the railway industry in the UK, including many other countries, is in the right stage to invest in automation   .