Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Discussion <s> Despite the recent achievements in stable dynamic walking for many humanoid robots, relatively little navigation autonomy has been achieved. In particular, the ability to autonomously select foot placement positions to avoid obstacles while walking is an important step towards improved navigation autonomy for humanoids. We present a footstep planner for the Honda ASIMO humanoid robot that plans a sequence of footstep positions to navigate toward a goal location while avoiding obstacles. The possible future foot placement positions are dependent on the current state of the robot. Using a finite set of state-dependent actions, we use an A* search to compute optimal sequences of footstep locations up to a time-limited planning horizon. We present experimental results demonstrating the robot navigating through both static and dynamic known environments that include obstacles moving on predictable trajectories. <s> BIB001 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Discussion <s> The task of cleaning a vertical flat surface with the help of a standing humanoid robot is considered. A trajectory/force tracking controller is introduced that is implemented under a mixed position/torque control mode. The arm joints are controlled with a conventional PD controller working under position control, while the ankle joints are torque controlled. The desired force is realized via a force tracking controller using CoM and ZMP position readings obtained from the pressure sensors in the feet. The trajectory/force tracking controller is implemented and experimentally evaluated with a miniature humanoid robot HOAP-2. <s> BIB002 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Discussion <s> The HIT load-carrying exoskeleton is designed for enhancing the operator’s load-carrying capability. Human walking has the characteristics of diversity and randomness. It requires that the sensing system of exoskeleton could detect and identify the random motion of human body. In this article, a human–machine force interaction designing architecture is proposed for HIT load-carrying exoskeleton. The human–machine interactive forces at the kinematic terminals (the back and feet) are detected for the human movement identification. Four basic body modalities during the movement process are proposed, which could be automatically identified by the sensing system. The kinematic models for the swing leg and supporting leg are established, respectively. A positional deviation feedback control method based on the interaction force detection is designed. The experiments show that the human–machine interaction force detection at the back and feet and the identification of different body modalities and movement inten... <s> BIB003 </s> Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review <s> Discussion <s> Adaptation is critical for effective team collaboration. This paper introduces a computational formalism for mutual adaptation between a robot and a human in collaborative tasks. We propose the Bounded-Memory Adaptation Model, which is a probabilistic finite-state controller that captures human adaptive behaviors under a bounded-memory assumption. We integrate the Bounded-Memory Adaptation Model into a probabilistic decision process, enabling the robot to guide adaptable participants towards a better way of completing the task. Human subject experiments suggest that the proposed formalism improves the effectiveness of human-robot teams in collaborative tasks, when compared with one-way adaptations of the robot to the human, while maintaining the human’s trust in the robot. <s> BIB004
The study reveals a strong case for the necessity of RAS in railway maintenance to improve the safety of passengers and railway workers, quality and reliability of the service, and to mitigate unpredicted expenses through preventive maintenance. It has been revealed that the majority of RAS developments focus on rolling-stock and rail track maintenance tasks, which are justifiable, as said constituents play a major role in the railway industry. Further, it has been realized that the majority of RAS developments in the subject area focus on inspection and monitoring, which are maintain the advantage of computer vision and supervised machine learning algorithms. Therefore, it would be advantageous if more research were conducted on applied robotics to elevate the mechanical engineering aspect of such systems. For instance, introduce collaborative robots to support maintenance technicians in railway depots BIB004 , develop a robotic system to conduct scheduled maintenance tasks, such as front end inspection and service of rolling-stocks or to service rolling-stock brake system, equip railway workers who handle heavy tasks with load carrying exoskeletons to minimize muscular fatigues BIB003 , or adopt humanoid robots from service robotic sector to handle complex railway maintenance tasks BIB002  BIB001 . On the other hand, the majority of inspection tasks tend to exploit SVM, which is a supervised machine algorithm to detect the presence of components or to classify the condition of a component as good or damaged. For example, there are several applications for detecting missing bolts and screws, but it emerges that there is not enough research to detect a loose screw or bolt. Further, more examinations are required to exploit different classification algorithms other than SVM in the railway maintenance field. In addition, the detection of smaller railway components in unstructured and dynamic environments is non-trivial. For instance, the detection and localization of connectors of the automatic train coupler electric head pins or detection of wire-locks used to secure drain/filler plugs in certain rolling-stock gearboxes, such as Siemens Class 380  . Furthermore, it is required to make robotic systems as flexible as possible while using off the shelf robots than introducing fully customized designs that yield higher costs, deficit in flexibility, and longer development periods  . Flexible and easily reconfigurable RAS developments will provide the ability to deploy the RAS in multiple tasks to attain benefits, such as shorter financial recovery periods and space saving. Further, such systems are viable through the proper design of layout, path planning, and development of intelligent and reconfigurable end of arm tooling. For instance, deploy a robot mounted on a rail or a scissor lift to clean train cab front and inspect automatic train coupler or utilize a robot that is mounted on a moveable platform to perform both transmission fluid and brake service tasks.