Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> RAS in Rolling-Stock Cleaning <s> Cleaning of rolling stock and stations is very important work in supplying comfortable service to customers. However, there are some problems with cleaning work, e.g. lack of workers who are getting older. To improve these problems, the East Japan Railway has developed several kinds of robots for cleaning. Here, I explain four types of floor cleaning robots. The first is a dust-collecting robot (the sweeper-type robot) for corners of station floors, the second is a cleaning robot (the scrubber-type robot) for use throughout a station and the third is a floor cleaning robot for commuter rail cars, all of which are self-propelled. The last one is a bonnet cleaning robot for Shinkansen rolling stock which has special axis mechanisms and a running mechanism. <s> BIB001 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> RAS in Rolling-Stock Cleaning <s> The tractor-model washing system is usually used in the technical process of maintenance for the vehicles in urban mass transit system and its efficiency is lower. On the basis of study and investigation, a self-traction model system has been developed. After a vehicle set is driven by its motors to go through the washing section and the trainset stopped at certain place, the mobile robotic platform will move to the vehicle set by its two propulsive wheels driven by VVVF (variable speed and variable voltage) inverter. The washing motion of shape-adaptation and the synchronized drive of robotic platform are implemented by neutral cell self adaptive algorithm and Cross-Coupling Control (CCC) algorithm. A variable quantity water control algorithm is designed for the goal of energy-saving and water-saving. Several-year actual running shows that it can work effectively and durably. <s> BIB002 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> RAS in Rolling-Stock Cleaning <s> Abstract This paper presents and briefly describes the methodology used to get the systems and conceptual design of a train cab front cleaning robot. While the sides of the trains are cleaned by a mechanised washer, the cab fronts are cleaned manually which imply a number of health and safety issues. The aim of this project is first to carry out an analysis of the current procedures in order to detect the possible gaps in the process, generating a list of requirements that will make possible the conceptual design of a cleaning system that fulfil those requirements. The proposed solution includes the division of the system in various subsystems where different solutions for each subsystem will be considered, analysed and selected as a final option to develop a prototype. This paper focuses in the main structure of the robot that holds the end-effector; different conceptual designs are shown that comply with the requirements set in the systems design. <s> BIB003 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> RAS in Rolling-Stock Cleaning <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> BIB004
Hiroshi Yaguchi BIB001 has successfully introduced two robots to clean rolling-stock in East Japan Railway company, one to clean commuter rail car floors and another to clean the bonnet of Shinkansen, high-speed Japanese trains. A mobile robot is developed to clean the commuter rail car floors in conjunction with Toshiba Co. Ltd. The developed robot weighs approximately 93 kg, which consists of ultrasonic sensors and encoders for navigation, and optical and touch sensor for safety. This robot can be operated in both automatic and manual modes, and its capabilities include sweeping the floor, collecting dirt, sprinkling water, mopping the floor, pulling dirty water, and polishing the floor. The robot takes about 15 min. to clean a single car. The navigation of robot is done by dead reckoning-tracking the desired path and its position by encoder data, while any positional error is corrected using distance sensors BIB001 . The second robot is developed to clean the Shinkansen train bonnet with the collaboration of Uchida Oil Hydraulics Mfg Co. Ltd. and ShinMaywa Industries Ltd. Previously, the cleaning process of Shinkansen bonnet was carried out by six maintenance workers. The design challenges of the robotic system included demand for a large work envelope, compact rest position, and ability to move along and lateral directions to the train. Therefore, researchers have designed an eight-axis articulated robot mounted on a mobile platform that was capable of moving along the full-length of a Shinkansen train and across three service bays in the lateral direction. The main control method of the robot was point-to-point teaching and playback. Hiroshi has concluded the main challenges in both RAS applications to be cost and ability to sense environment/target effectively BIB001 . A self-traction-model to clean urban mass transit vehicles was proposed by Xu et al. The washing apparatus is mounted on a mobile vehicle platform, which is driven by a variable speed and voltage inverter. The motion and path planning of the manipulator is achieved by the neutral cell self-adaptive and Cross-Coupling Control algorithm. Further, a novel variable water control algorithm is incorporated into the system to make it energy and water efficient. The researchers claim that the system has gone through years of testing in various depots and was proven to work efficiently and robustly BIB002 . Further, there are some conceptual designs and ongoing research to introduce RAS in rolling-stock cleaning tasks. For example, Tomiyama et al. BIB003 have presented a systematic analysis of the train cab front cleaning task and generated subclasses that will enable researchers to efficiently and effectively find solutions to each sub-task. Further, this study presents several conceptual designs of cab front cleaning robots and two illustrations of robotic arms are provided. In contrast to Hiroshi Yaguchi's bonnet cleaning robot, Tomiyama et al. have divided the work envelope into two along the vertical symmetric line of the train and positioned two identical robots in each side BIB001 BIB003 . Furthermore, Moura and Erden BIB004 presented a theoretical control and path planning methodology for a train cab front cleaning robot by exploiting the operational space formulation and simultaneous force and position control introduced by Khatib [31,32].