Railway Train Research Articles

Integrated train timetable with supply–demand interactions at the Chinese high-speed railway

In traditional Chinese railway operations, train timetable and unit assignment are usually separated from pricing and seat allocation, resulting in a decrease in revenue and an increase in operating costs. In this paper, we study the integrated problem of train timetable, unit assignment, pricing, and seat allocation, where passenger choice behavior is modeled by the multinomial logit (MNL) model. This integration enables us to explicitly capture supply–demand interactions. The problem is formulated as a mixed integer nonlinear programming model with the objective of maximizing total profit. By converting the MNL model into its equivalent convex form, we recast the model as a tractable reformulation, allowing the use of a general-purpose solver to solve practical-sized instances. Based on real data from high-speed railway lines in China, three sets of case studies are conducted to validate the effectiveness and efficiency of the proposed approach.

Routing and scheduling of trains and engines in a railway marshalling station yard

In a busy railway marshalling station, train and engine traffic management in the receiving/departure yard plays a crucial role in efficient and stable operations. Traditionally, a track assignment problem (TAP) is solved to assign tracks to trains for berthing at a receiving/departure yard. However, the TAP does not encompass shunting operations in the yard (e.g., engine replacement and train disassembly), which can result in additional scheduling challenges for dispatchers and route conflicts between operations. This paper investigates a train and engine routing and scheduling problem (TERSP) in a receiving/departure yard of railway marshalling stations, which involves simultaneously assigning routes and scheduling route-setting start times for both train and shunting operations to be conducted in the yard. By introducing the concepts of task, activity, and pattern, we transform the original problem into assigning pre-generated patterns incorporating both route and route-setting start time alternatives to activities. The transformed problem is formulated into a compact binary integer linear programming model with a linear number of constraints and the objective of minimizing the total time deviation of all involved tasks. An improved technique that relies on listing all maximal (bi)cliques in a constructed graph is designed to effectively model the time coherence and track section occupation constraints. A heuristic that gradually expands the patterns for the identified key activities by adding more start time alternatives is applied to remedy an infeasible model caused by potential route conflicts. In addition, a rolling horizon algorithm that decomposes the original problem into consecutive smaller stages using either a time-rolling or a train-rolling rule is developed to efficiently solve instances. Finally, numerical experiments based on the physical layouts and real timetables of a receiving yard and a departure yard of a large marshalling station in China are conducted to assess the performance and applicability of our proposed approaches. The results demonstrate that our approaches typically find (near-)optimal solutions within several minutes for the investigated instances by simultaneously addressing different classes of yard operations and resources.

Optimizing passengers’ experience: A goal-oriented reinforcement learning speed control approach for urban railway trains

Prolonged vibration can be uncomfortable for passengers utilizing urban rail transit systems. This study proposes an automatic speed control framework for urban railway trains to reduce vertical vibrations experienced by passengers. We suggest the concept of the “segmented comfort speed limit” to represent the vertical passing comfort of oncoming sections. This speed limit is calculated from 1/3 octave band acceleration and smoothed through lag-type speed control mode. The deep deterministic policy gradient algorithm with hindsight experience replay mechanism (HER-DDPG) is designed, to balance safety, comfort, and energy efficiency driving. Verify the speed control framework based on HER-DDPG through the rail data collected from Dalian Metro Line 12. Compared with the DDPG-based model, the vertical comfort is improved by 2.34%, and the longitudinal acceleration and total energy consumption are reduced by 45% and 8.1%. Compared with the real-world train control trajectory, HER-DDPG improves vertical comfort by 9.76% and reduces energy consumption by 12.4%. The results show that the proposed framework can effectively improve the ride experience of passengers.

Harmonic resonance evaluation and suppression of railway power conditioner-network-train coupling system

The coupling of railway power conditioner (RPC), network, and train will change the impedance characteristics of the existing traction power supply systems, which will lead to the unclear law of high-frequency harmonic resonance. This paper aims to study the resonance mechanism of the RPC-network train coupling system, and then solve the resonance problem of the existing traction power supply system from the perspective of reshaping the high-frequency impedance of the system. Firstly, the RPC-network-train coupling system’s dynamic node admittance matrix is established. After that, a comprehensive resonance evaluation method is proposed to obtain the resonance impact factors (RIFs) of multiple virtual impedances in the control strategy and the filtering parameters, which can realize the comparison and selection of five existing impedance reshaping strategies. To ensure the safe and stable operation of the RPC-network-train coupling system, a multi-objective sorting optimization strategy (MOSOS) considering resonance suppression, harmonics filtering, filter cost, and control system stability is proposed for the RPC based on the RIFs. Finally, the effectiveness of the proposed method is verified by the simulation result in MATLAB/Simulink and the experiment result in the StarSim hardware-in-the-loop (HIL) platform respectively.

Research on Train Loading and Unloading Mode and Scheduling Optimization in Automated Container Terminals

In some automated container terminals, railway lines have been implemented into the port, saving container transfer time. However, the equipment scheduling level of the railway yard needs to be improved for managers. In the equipment scheduling of loading and unloading containers for railway trains, the operation modes “full unloading and full loading” and “synchronous loading and unloading” are often adopted. Due to the long length of the railway yard and the line of one train, there are two ways to arrange loading and unloading tasks for automated rail-mounted gantry cranes (ARMGs): one is to pre-assign tasks for ARMGs, and the other is to not pre-assign tasks for ARMGs. To investigate the efficacy of these different operation modes and methods of assigning tasks, this study formulated three mixed-integer linear programming (MILP) models with the goal of minimizing the ARMG task completion time. An adaptive large neighborhood search algorithm was used to tackle the scheduling problem. The scheduling effects of different operation modes and methods for assignment tasks were compared in terms of their calculation time and the completion time of ARMG tasks. Notably, the findings reveal that, with an increase in the number of tasks, the “pre-assign” task arrangement had a limited effect on the completion time of the ARMG tasks, made the calculation time shorter, and reduced the complexity of the problem. From the perspective of the completion time of ARMG tasks, the time under the “synchronous loading and unloading” operation mode was less than that of the “full unloading and full loading” operation mode. Therefore, it is recommended that the managers of the railway yard in an automated container terminal adopt the “synchronous loading and unloading” operation mode but determine the task assignment method according to decision time requirements. In addition, when the number of tasks is large, to decrease the time to complete ARMG tasks, the manager can adopt the “non-pre-assign” task distribution method.

A novel energy harvesting technology from the movements of air masses

The displacement of air masses caused by the movement of objects or vehicles is often characterized by considerable energy content, which, with appropriate technologies, can be partially recovered. In this sense, numerous scientific works consider rail transport as a possible context for application. However, the literature in the sector highlights how using existing wind technologies in these areas involves many difficulties, mainly related to the turbulent and impulsive nature of the airflows generated. This work presents the architecture and general aspects of an innovative technology for obtaining electrical energy from variable and impulsive airflows, such as those due to the rapid transit of railway trains in tunnels, without precluding its use in other similar fields. The innovative aspect mainly concerns the independent control of two distinct typologies of bladed elements, which can also have translational movement and drag-based and lift-based aerodynamic behavior to improve the adaptability of the embodiment to the site’s fluid dynamic and geometric characteristics. Furthermore, the structural simplification of the apparatus, shifting some of the technological complexity to the control systems, brings further advantages in terms of construction cost, robustness, maintenance, reuse, and transferability to different contexts. Of course, the counterpart of these benefits lies in the software and hardware of the control devices. Analytical models to determine the non-dimensional performance coefficients of the two basic types have been reported as has the architectural model of the control system. The technology shown in this work is protected by an EP and US Patent.

Distributed virtual formation control for railway trains with nonlinear dynamics and collision avoidance constraints

To improve the model accuracy and control efficiency for the movements of a virtual formation, this paper investigates distributed optimal control for the virtual formation control system in railways. Adopting the relative distance braking mode, a coupled optimal control problem with nonlinear train dynamics and constraints regarding collision avoidance and jerk is formulated for the virtual formation. To handle the non-convex constrained problem efficiently, a distributed augmented Lagrangian based alternating direction inexact newton (ALADIN) method under the model predictive control (MPC) framework is developed. For the execution of the distributed computational process, the copied variables are introduced to reformulate the original coupled problem in an objective separable form. By exploiting the problem separability, the ALADIN method decomposes the reformulation into a coordinated quadratic programming problem of small-scale and several local nonlinear programming problems that can be calculated in parallel, thereby facilitating real-time control and relieving communication burden. Numerical experiments on a metro line are carried out to verify the effectiveness of the proposed model and method. Experimental results demonstrate that high-performance tracking control for virtually coupled train units can be achieved in real time.

Design of PID control model for reducer based on Simulink simulation

At present, modern industry is developing rapidly, and the level of industrial automation is gradually improving. Many production lines use a large number of mechanical equipment and robots, and reducers play a key role in these equipment, helping to control and adjust the speed and torque of various moving parts, achieving efficient production. At the same time, in high-speed railway trains and airplanes, reducers improve the efficiency of engines and turbines, reduce fuel consumption, and ensure safe and reliable operation. However, traditional reducers have drawbacks such as low accuracy and long adjustment time in controlling speed. This article adopts the method of PID control of the reducer, and uses the Simulink platform of Matlab to build a control model of the reducer. At the same time, negative feedback control is applied to the speed and current, forming two PID closed-loop controls: current loop and speed loop. The speed waveform and current waveform are displayed on an oscilloscope, and the simulation control results are analyzed. The simulation results show that by using a PID controller to control the speed of the reducer, the maximum overshoot can be reduced, the adjustment time can be shortened, the adjustment process can be smoother, and the set value can be reached quickly.

A passenger service revolution? Transport design and passenger experience on Tokyo’s urban railway network, c. 1945–2010

This article discusses the history of efforts to shape passenger experience aboard urban railways through transport design. Taking Japan National Railways (JNR) trains as a case study, it examines the development of design interventions and organisational polices seeking to increase passenger comfort on Tokyo’s urban railway network in the second half of the 20th century. Industry and popular accounts have often tied the improvement of transport quality and passenger experience aboard JNR trains to its privatisation in 1987. In contrast, this article shows that passenger-oriented transport design has been an integral component in a continuous project to make urban railway travel more pleasant that long preceded this 1987 change in governance structures but has been held back by organisational and structural challenges. In doing so, it highlights that transport design involves the conscious shaping of both the “hardware” (i.e. physical transport infrastructure) and “software” (i.e. passenger-staff interactions) of service, as well as the backstage modification of organisational structures and processes that facilitate this framework. Built on a qualitative analysis of Japanese industry publications, newspapers, and secondary sources, the article thus contributes to literature on passenger experience, mobilities design, and transport history.

Bayesian Spatio-Temporal Graph Convolutional Network for Railway Train Delay Prediction

Bayesian Spatio-Temporal Graph Convolutional Network for Railway Train Delay Prediction

High-speed train drivers’ human error under fatigue and stress: the role of situation awareness and individual differences

Fatigue and stress are critical variables that impair railway train drivers’ safety performance, and individual differences may influence these effects. This study investigates how fatigue and stress affect high-speed train drivers’ human error and the role of individual differences. We hypothesised that situation awareness (SA) mediates the effects of fatigue and stress on human error, and individual differences (age and work experience) moderate these effects. We surveyed 1,391 male drivers from eight Chinese railway bureaus and used PROCESS Macro for data analysis. The results revealed that fatigue and stress increased human error, directly and indirectly through SA. Age and work experience moderated the effect of fatigue and stress on SA, respectively. Older drivers had better SA under high fatigue, while more experienced drivers had better SA under high stress. These findings can inform more tailored safety management strategies to lower human error and enhance the safety of high-speed train operations.

Innovative approaches to developing national railway safety policy and training safety leaders

Innovative approaches to developing national railway safety policy and training safety leaders

Mechanics based lateral stability design for a railway Electric Multiple Unit

This paper presented a mechanics-based method to address the typical lateral stability issue of railway trains. A Base Electric Multiple Unit (Base EMU) and an upgraded EMU were used as the research objects. Mechanics-based models were developed for both systems; the Base EMU model was validated using actual test data. Different wheel-rail equivalent conicity values and suspension parameters were investigated. The results showed that inadequate wheel-rail guiding capacity under low conicity can led to the occurrence of lateral stability issues. When the train is pushed by motor cars, coupler lateral forces aggravate stability issues. Altering the yaw damper’s angle and damping properties can significantly reduce lateral swaying and improve the ride index. This represents a low-cost and favored solution. Decreasing the stiffness of the axle box pull rod is also effective in mitigating low-frequency lateral swaying.

The Influence of EMU Driver Education and Training on Train Driver Competency Indonesian High Speed Rail “Whoosh”

The Jakarta Bandung High Speed Train is a mass transportation that is a long-term permanent solution that is expected to overcome road traffic congestion on urban roads and roads to Bandung, two areas that are projected in the future to become megapolitan areas, roads in the surrounding area, reduce carbon emissions and air pollution, as well as effective steps to shift private vehicle users to mass transportation effectively (Ministry of Transportation, 2022). In order to increase the competence of the crew of fast train railway facilities, PT Kereta Cepat Indonesia China (PT.KCIC) in collaboration with the Indonesian Railway Polytechnic in Madiun organized EMU Driver education and training. The following is the number of EMU Driver education and training participants who do not yet have a certificate of competence for the crew of fast train railway facilities. While the questionnaire results on the Railway Suggestion crew competency variable are also dominated by answers agreeing or with an average of 82.99%. With these results it can be interpreted that after attending EMU Driver education and training affects the Competence of the Railway Facilities Crew where the results of the regression analysis obtained Y21.323 + 0.412. The intercept value is 21,323 which means that without the X variable, the competence of the crew of the railway facilities remains the value, namely 21,323. The t test data has a t count of 5.821 while the t table at the 5% level for 32 respondents is 2.014. Because t count t table then Ho is rejected and Ha is accepted. with a significance value of 0.000 (0.0000.05) This can be interpreted that EMU Driver education and training has a positive and significant effect on the competence of the crew of railway facilities.

О моделировании развития и тушения пожара при паромной перевозке железнодорожных составов

В статье рассмотрена проблема моделирования пожаров железнодорожных составов, перевозимых паромами. Показано, что такие пожары могут принимать каскадный характер, т.е. возгорание одного вагона может привести к возгораниям соседних вагонов, в результате чего масштаб пожара значительно возрастает. Показано, что такие пожары на паромах в плавании могут привести к трагическим последствиям, в том числе и к масштабному экологическому инциденту ввиду низкой огнестойкости корпуса судна и невозможности оказания оперативной помощи извне. Для описания процессов горения и тушения вагонов применён математический аппарат цепей Маркова с непрерывным временем. Получены аналитические выражения для характерных сценариев пожара и приведены соответствующие расчётные оценки вероятностей состояния парома. Сделаны выводы о целесообразности дальнейших исследований в части моделирования пожароопасных ситуаций с разными типами перевозимых вагонов и совершенствования соответствующих нормативных документов. The article considers the problem of modeling fires of railway trains transported by ferries. It is shown that such fires can take on a cascading character, i.e. the ignition of one car can lead to fires of neighboring cars, as a result of which the scale of the fire increases significantly. It is shown that such fires on ferries during navigation can lead to tragic consequences, including a large-scale environmental incident due to the low fire resistance of the vessel's hull and the inability to provide operational assistance from the outside. To describe the processes of burning and extinguishing wagons, the mathematical apparatus of Markov chains with continuous time is used. Fire Analytical expressions for typical fire scenarios are obtained and corresponding estimates of the probabilities of the ferry condition are given. Conclusions are drawn about the expediency of further research in terms of modeling fire-hazardous situations with different types of transported wagons and improving the relevant regulatory documents.

Enhanced heat transfer for subway linear motor through underbody flow regulation

The low-speed flow, restricted tunnel environment, and degraded motors have resulted in a serious challenge in the underbody equipment of subway trains, where overheating of multiple longitudinally aligned linear induction motors is one of the most urgent challenges to be resolved. In the face of this problem, the flow field distribution of a 4-car formation subway train is investigated. Two deflector installation designs are proposed to regulate the underbody flow using the passive flow control method to enhance the heat dissipation of motors. The influence of deflector installation is analyzed through an experimentally verified conjugated heat transfer numerical method. The results showed that the installation of deflectors can significantly enhance the longitudinal underbody flow. On the one hand, the deflector can effectively enhance the momentum exchange between underbody flow and the surrounding undisturbed flow field. On the other hand, the deflectors can break the large lateral vortices, such that the flow resistance along the longitudinal direction is reduced. Besides, the deflectors can also reduce the size of the wake behind the motor. As a result, the increased incoming flow rate ahead of motors effectively alleviated the overheating issue. The enhancement of heat transfer between different deflector installation designs was compared. It was found that the vertical edge of deflectors should be installed as close to the lateral edge of the subway car as possible. The maximum temperature of motors has been reduced by 9 % according to the installation design proposed in this study. The outcomes of this study can also provide theoretical guidance as well as engineering solutions for the cooling design of bottom heat sources and other similar overheating devices in thousands of railway trains with exposed underbody compartment. The convection enhancement around the heating devices can be realized by the surrounding flow field regulation method proposed in this study.

A Time Headway Control Scheme for Virtually Coupled Heavy Haul Freight Trains

Abstract Virtual coupling of railway trains is an emerging technology that has the potential to significantly increase railway operational efficiency by reducing the train following distance from absolute braking distances to relative braking distances. Current research in this topic is mainly focused on passenger trains and uses distance-based headways. This paper studied virtual coupling for heavy haul freight trains and demonstrated that the distance headway scheme was challenging and sometimes impractical for heavy haul trains to achieve virtual coupling. A time-based headway scheme was then proposed to set the follower train to be a certain time behind the schedule of the leader train rather than a distance headway. The time-based headway required the follower train to reproduce the leader train's operational status at the same track location. This also allowed the follower train to copy any optimized train driving strategies from the leader train. Demonstrative simulations were carried out without the consideration of communication errors and train localization errors. The results show that a conventional distance headway simulation had maximum distance and speed errors of 716 m (36%, reference 2 km) and 24 km/h (66%, reference 36 km/h), respectively. A time-based headway simulation reduced the maximum distance and speed errors to 0.07 m (0%, reference 2 km) and 0.1 km/h (9%, reference 1.18 km/h), respectively.

Railway Train Collision Avoidance on Same track and Animal Detection Using AI - IoT

The increasing demand for safer and more efficient railway transportation systems has prompted the exploration of advanced technologies to mitigate collision risks and address emerging challenges such as animal incursions on railway tracks. This paper proposes a comprehensive solution leveraging Artificial Intelligence (AI) and Internet of Things (IoT) technologies for real-time detection and avoidance of collisions between trains operating on the same track and encounters with animals. These sensors capture various environmental and operational data such as train positions, velocities, and track conditions. The AI algorithms analyze this data to identify potential collision risks and animal intrusions. Additionally, real-time communication between trains and the centralized control system enables timely intervention and rerouting decisions to ensure safe operations. The system incorporates advanced image recognition algorithms to detect and classify animals near railway tracks. Utilizing high-resolution cameras and IoT-connected devices, the system identifies animals in the vicinity and alerts train operators or initiates automated braking mechanisms to prevent accidents caused by animal incursions. Key features of the proposed system include scalability to accommodate varying railway infrastructures, adaptability to diverse environmental conditions, and interoperability with existing railway signaling and control systems. Moreover, the integration of AI and IoT technologies enhances the system's predictive capabilities, enabling proactive risk mitigation and improving overall.

Strain Cyclic Characteristics and Ratchetting Behaviors of High-Speed Railway Train Axle Steel EA4T

Strain Cyclic Characteristics and Ratchetting Behaviors of High-Speed Railway Train Axle Steel EA4T

Railway Signal Electronic Control System Based on BP Neural Network

Railway signal system is the core system of railway command train operation. After the installation of the system equipment is completed, a comprehensive test shall be carried out through joint debugging and joint testing, and the applicability of the system to the design requirements shall be generally evaluated according to the test results. This paper focuses on the research of railway signal electronic control system. Based on BP neural network, fault information can be quickly and accurately identified in a relatively short time, and accurate electronic signal control can be realized in a complex system environment. The final result of the study shows that the difference in delay error of railway signal transmission under BP neural network technology is small, there are some subtle differences in 5 different modes, but the impact is small, in mode 1, the target time value is 0.236s, The actual reflection time is 0.322s, it can be seen that the error is controlled within 0.2s, which is feasible. Through the analysis of delay error of railway signal electronic control system, BP neural network has certain advantages in railway signal transmission.