Smart Railway Research Articles

Multicarrier Tandem Spreading Multiple Access (MC-TSMA) for High-Speed Railway (HSR) Scenario

As the paradigm of the next high-speed railway (HSR) evolution, the smart railway attracts increasing attention from various professionals. With the maturity of 5G technologies, numerous intelligent applications are expected to be enabled. Therein, the Internet of Things (IoT) for railway can be supported by the massive machine-type communications (mMTCs) system. Recently, a novel multiple access scheme named tandem spreading multiple access (TSMA) has been proposed for the grant-free random access procedure in mMTC. However, high mobility has not been considered in TSMA so that it cannot be employed in IoT for railway currently. In this article, multicarrier TSMA (MC-TSMA) is introduced and the high-speed adaptability is investigated. Particularly, the impact of Doppler shift and time-varying channel is analyzed. In the meantime, the corresponding improvement designs are proposed. The simulation results show that the proposed scheme can effectively mitigate the impact of high mobility on MC-TSMA.

Multitime-Scale Optimal Dispatch of Railway FTPSS Based on Model Predictive Control

The flexible traction power supply system (FTPSS) integrates back-to-back converter, and hybrid energy storage system (HESS) and photovoltaic (PV) generation system will be an important part of the smart railway. The FTPSS not only cancels the neutral zone but also facilitates the utilization of regenerative braking (RB) and renewable energy, but the random fluctuation of PV and the sudden change of traction load will exert influence on the safe and efficient operation of the FTPSS. To improve the benefits of FTPSS and compensate for the imbalance between supply and demand in short-term operation, a multitime-scale optimal dispatch method is proposed for flexible railway energy management (FREM), which integrates day-ahead dispatch and intraday feedback correction. During the day-ahead dispatch, the minimizing operating costs problem is formulated as a mixed linear programming model by coordination between HESS, RB, and PV output. For intraday energy adjustment dispatch, a rolling optimization based on model predictive control combined with the feedback correction method is proposed, with aim of minimum operation deviation of FTPSS because of adjusting the HESS dispatch plan drew up at day-ahead. Finally, the effectiveness of the proposed FREM control strategy is verified by the detailed real case study of a railway line in China.

5G Key Technologies for Smart Railways

Railway communications has attracted significant attention from both academia and industries due to the booming development of railways, especially high-speed railways (HSRs). To be in line with the vision of future smart rail communications, the rail transport industry needs to develop innovative communication network architectures and key technologies that ensure high-quality transmissions for both passengers and railway operations and control systems. Under high mobility and with safety, eco-friendliness, comfort, transparency, predictability, and reliability. Fifth-generation (5G) technologies could be a promising solution to dealing with the design challenges on high reliability and high throughput for HSR communications. Based on our in-depth analysis of smart rail traffic services and communication scenarios, we propose a network slicing architecture for a 5G-based HSR system. With a ray tracing-based analysis of radio wave propagation characteristics and channel models for millimeter wave (mmWave) bands in railway scenarios, we draw important conclusions with regard to appropriate operating frequency bands for HSRs. mymargin Specifically, we have identified significant 5G-based key technologies for HSRs, such as spatial modulation, fast channel estimation, cell-free massive multiple-input-multiple-output (MIMO), mmWave, efficient beamforming, wireless backhaul, ultrareliable low latency communications, and enhanced handover strategies. Based on these technologies, we have developed a complete framework of 5G technologies for smart railways and pointed out exciting future research directions.

Smart Railway Operation Aid System for Facilities With Low-Safety Requirements

Rail traffic control systems are undergoing an important transformation. ERMTS/ECTS, CBTC, PTC and other train control systems based on radio communication are being deployed in different countries. These systems meet the high safety requirements for passenger traffic, and cover from congested urban areas to high-speed trains. However, there is a set of facilities, such as ports, dry ports, facilities for the repair and maintenance of trains, logistic centers, mines, etc., whose trains, that only carry freight, circulate in a controlled environment at a low speed. These facilities have low safety requirements. For them, present commercial systems become too expensive, so that, in most cases, railway traffic is still handled manually. This paper presents a system to aid in the exploitation of rail traffic for this type of facilities, called SFPS (Seville Ferro-Port System). SFPS presents many of the features of the most advanced traffic control systems, but incorporates innovations based on Information and Communications Technologies to reduce costs. To this end, train location is based on a satellite global positioning system, physical signs are replaced by virtual ones, displayed in an On-Board Unit, and communication is almost entirely wireless. SFPS has been in a trial phase since March 2016, covering part of the railway facilities of the Port Authority of Seville, with satisfactory results.

Stability Analysis of a DC MicroGrid for a Smart Railway Station Integrating Renewable Sources

A low-level distributed nonlinear controller for a DC MicroGrid integrated in a Smart Railway Station capable to recover trains’ braking energy is introduced in this paper. The DC MicroGrid is composed by a number of elements: two different types of renewable energy sources (regenerative braking energy recovery from the trains and photovoltaic panels), two kinds of storages acting at different time scales (a battery and a supercapacitor), a DC load representing an aggregation of all loads in the MicroGrid, and the connection with the main AC grid. The nonlinear model of the MicroGrid is introduced, and a complete stability analysis is investigated to the purpose to meet power balance and grid voltage stability requirements. An Input-to-State Stability (ISS)-like Lyapunov function is obtained with a System-of-Systems approach, and it is utilized to develop the control laws for the converters in order to fulfill the dedicated objective each of them has. Simulation results, showing the desired grid behavior using the proposed nonlinear control laws, are introduced and compared with classical Proportional Integral (PI) linear controllers, with respect to performances and parametric robustness. The DC MicroGrid is shown to be able to operate braking energy recovery while performing load feeding and renewable energy integration and guaranteeing a proper DC voltage profile.

A Review Paper on "Smart Railway Crossing using Microcontroller"

A Review Paper on "Smart Railway Crossing using Microcontroller"

Zero On-Site Testing Strategies for Wireless TCMS

TCMS is a key element for smart railway operation and maintenance. In order to reduce costs and train weight, EU-funded projects are working on the development of wireless TCMS. The data exchanges between trains and ground will be based on wireless technology such as WiFi or Long Term Evolution. First prototypes are available at the European level. To facilitate the testing of the TCMS interface to ground systems, it is important to develop tools able to represent railway environments without going on tracks (zero on-site testing). In this context, we present two strategies to simulate and emulate a complete wireless network (including the core network), based on the Riverbed Modeler and OpenAirInterface platform, able to take into account various train-to-ground contexts (environment, communication and railway networks load). This work considers LTE technology but can be transposed to other types of technology if representative system models are available. As a proof of concept of the test environment, we present results in terms of delay and delivery rates considering TCMS traffic and various railway scenarios such as train speed and wireless network load.

Propagation and safety analysis of the train‐to‐train communication system

Smart railway transportation systems aim to make the trains operate in a more intelligent and flexible manner. Reliable train-to-train communication, which can increase the efficiency and safety of the train operation, is getting more concern in recent researches, and different communication solutions can be applied to carry out the data communication. However, its propagation and safety analysis is not systematically put forward. In this work, the structure and working principle of a train-to-train communication system are proposed. In order to have a better performance, multi-communication channels are involved. Three different modems are applied to make sure that the system can implement the communication task in different situations. What is more, the long-range communication modem provides not only long distance communication but also distance measurement between two trains. The propagation analysis based on different carrier waves and application scenarios is discussed. The system safety is evaluated by means of Petri nets, and the analysis procedure can be reused for analysing different system structures.

Smart Railway System

Smart Railway System

Modeling and field-test of a compact electromagnetic energy harvester for railroad transportation

To enable the smart technologies and safe operation of transit and rail transportation, such as hot box detector, track health monitoring and wireless communication on the railroad side, a cost-effective energy source is in need. This paper presents the design, modeling, in-lab experiment and field-test results of a compact ball-screw based electromagnetic energy harvester with a mechanical motion rectifier (MMR) mechanism for smart railway transportation. The MMR mechanism is realized by the embedded one-way clutches in the bevel gears, which converts the bi-directional track vibration into the unidirectional rotation of the generator. Compared to previous designs, the proposed harvester has reduced backlash and thus can harvest energy from a small input of the track deflection induced by the moving train. Two prototypes with different key design parameters were built and tested. A comprehensive model considering the train-rail-harvester interaction was developed to analyze the dynamic characteristics of the coupled system and predict the energy harvesting performance of the harvesters at different train speeds. Both in-lab and field tests were carried out to examine the energy harvesting performance of the harvesters and validate the model. Field test results illustrated that an average power of 1.12 W and 2.24 W were achieved for two prototypes respectively when a Type A rapid transit passed by with a 30 km/h vehicle speed.

Research and Analysis on the Top Design of Smart Railway

Deepening the informatization and intelligent construction of railways has become an inevitable choice to promote the innovation and development of railways and enhance their core competitiveness.At present,China has in-depth research in smart cities,smart transportation and other fields, but the research on smart railways is still in its infancy, and it is urgent to make plans for the development of smart railways to provide guiding suggestions for the development of railway informationization.Based on the research results of smart cities and smart transportation in related fields at home and abroad, combined with the application trends of internet technology and big data technology in railway informatization, this paper attempts to give a clear definition of smart railway from the perspective of smart city development. It also proposes the overall structure of the top-level design of the smart railway, and the application of the smart railway in combination with the development needs of the construction of the Jing-Zhang high-speed railway.

An Efficient MIMO Channel Model for LTE-R Network in High-Speed Train Environment

Long-term evolution for railway (LTE-R) represents a promising network for smart railway, enabling fast and reliable wireless communications on high-speed trains (HSTs) with speeds as high as 500 km/h. To the best of our knowledge, the existing channel models are insufficient to assess such performance. To fill this gap, we propose the tapped delay line model for a $2\times 2$ multiple-input multiple-output channel in typical LTE-R HST scenarios. The models are efficient, yet flexible, which can capture the essential channel characteristics in the delay domain, Doppler domain, and spatial domain. Due to the practical difficulties of HST channel measurements, the channel between the fixed transmitter and the high-mobile train cannot be recorded sufficiently for establishing these stochastic models. Therefore, we develop channel models using a ray-tracing (RT) simulator that is validated by HST channel measurements at 2.15 GHz. This paper gives a full parameterization for the proposed channel models, and presents their implementation in channel and link-level simulations. The verification is made through a comparison of the proposed models and the measurement-validated RT simulations in terms of the delay spreads, the eigenvalues, and the error vector magnitudes.

Influence Analysis of Typical Objects in Rural Railway Environments at 28 GHz

Millimeter wave (mmWave) is a key to realize high data-rate communication and enable smart railway services. There are more and more research work focusing on the algorithm and system design for railway communications in the mmWave band. A correct understanding of the mmWave channel characteristics for railway scenario is important for the estimation and evaluation of designed technologies. In this paper, the influence of typical objects in rural railway environment to the mmWave propagation channel is analyzed. Based on the channel measurement conducted at 28 GHz with train-to-infrastructure deployment in the rural railway environment, a ray tracing (RT) simulator is calibrated in terms of environment modeling and electromagnetic (EM) calculation. The dominant multipath components of the measurement are tracked and matched with corresponding objects in the propagation environment. Accordingly, dominant propagation mechanisms (direct, penetration, reflection, scattering, etc.) are determined, the three-dimensional environment model and the EM parameters of different objects are calibrated. To overcome the constraints of the measurement and analyze the influence more practically, the measurement campaign is extended to four different environment cases and four T2I deployments. With the predetermined dominant propagation mechanisms and calibrated EM parameters, reliable RT simulations are conducted. The influence of typical objects are analyzed for the considered environment cases and deployments. The analysis of this paper not only helps to understand the important influential factors of propagation channel at the object level, but also can be useful in guiding deployment of mmWave communication system. The provided EM parameters and environment modeling suggestions will enable reliable RT based channel realization in rural railway environments.

Symplectic analysis of stationary random vibration of vehicle–track coupled system with rail-borne electromagnetic generator

In this article, the authors establish the vehicle-track coupled model of smart railway track with rail-borne electromagnetic generator and conduct a symplectic analysis in frequency domain. A vehicle-track model considering vehicle traveling load is constructed, and the pseudo-excitation method is used. The frequency-dependent stiffness of rail pad is involved in the calculation model to get accurate results of rail natural frequency. The calculated results indicate that the smart railway track with electromagnetic generator will not affect the random vibration response of vehicle and bogie, but it could have certain influences on the wheelset and under-rail structure, especially the vibration response of rail, whose acceleration Power Spectrum Density difference reaches 18.6% with frequency shift of 54 Hz at basic frequency of 730.2 Hz, whereas the low frequency (below 200 Hz) rail vibration is not affected. The methods and results could serve as a guideline for the safety checking and dynamics calculation of smart railway track with rail-borne electromagnetic generator.

Energy Management of a Smart Railway Station Considering Regenerative Braking and Stochastic Behaviour of ESS and PV Generation

The smart grid paradigm has provided great opportunities to decrease energy consumption and electricity bills of end users. Among a wide variety of end users, electrical railway systems with their huge installed power capacity should be considered as a vital option in order to avoid wasted energy, provided that an energy management system is utilized. In this study, a mixed-integer linear programming model of a railway station energy management (RSEM) system is formulated by a stochastic approach, aiming to utilize the emerged regenerative braking energy (RBE) during the braking mode in order to supply station loads. Furthermore, the proposed RSEM model is composed of an energy storage system (ESS), RBE utilization, photovoltaic (PV) generation units, and an external grid in this paper. The passengers' impact on RBE as well as the stochastic behaviour of the initial state-of-energy of ESS along with uncertainty of PV generation by the RSEM model are also evaluated. The model is tested under a bunch of case studies formed considering several combinations of the cases that an ESS or PV are available or not and using RBE is possible or not.

Influence of Typical Railway Objects in a mmWave Propagation Channel

In the future railway services, wireless communication is the fundamental part and millimeter wave (mmWave) is foreseen to be a key enabler toward the smart railway. An accurate understanding of the propagation environment can assist designing both systems and railway infrastructures for better communication services. In this paper, the influence of typical objects to the mmWave propagation channel is analyzed for “train-to-infrastructure” and “intrawagon” railway scenarios with various configurations. Propagation measurements are conducted in the mmWave band for the 12 most common railway materials. The corresponding electromagnetic parameters are obtained, and a 3-D ray tracing (RT) simulator is calibrated. The mean absolute error of the simulated $S_{21}$ parameter is $-$ 53.5 dB, indicating that the calibrated RT can be used to generate the close-to-real mmWave channel for railway scenarios. Statistically consistent scenarios and deployments are generated, which enables drawing unbiased numerical results based on intensive RT simulations. The influence of typical objects and corresponding material compositions is then compared, and significant objects are determined for each scenario. The results of this work not only imply how the propagation environment impacts on the propagation channel, but also make suggestions to efficiently reconstruct railway environment models for an accurate RT-based channel model. Moreover, the understanding of the influence of the environment at object and material levels will, in turn, guide the construction of railway infrastructure for better railway services.

Internet of Things for Smart Railway: Feasibility and Applications

The explosively growing demand of Internet of Things (IoT) has rendered broadscale advancements in the fields across sensors, radio access, network, and hardware/software platforms for mass market applications. In spite of the recent advancements, limited coverage and battery for persistent connections of IoT devices still remains a critical impediment to practical service applications. In this paper, we introduces a cost-effective IoT solution consisting of device platform, gateway, IoT network, and platform server for smart railway infrastructure. Then, we evaluate and demonstrate the applicability through an in-depth case study related to IoT-based maintenance by implementing a proof of concept and performing experimental works. The IoT solution applied for the smart railway application makes it easy to grasp the condition information distributed over a wide railway area. To deduce the potential and feasibility, we propose the network architecture of IoT solution and evaluate the performance of the candidate radio access technologies for delivering IoT data in the aspects of power consumption and coverage by performing an intensive field test with system level implementations. Based on the observation of use cases in interdisciplinary approaches, we figure out the benefits that the IoT can bring.

Smart Railway Track Pedestrain Crossing without using Staircase

Smart Railway Track Pedestrain Crossing without using Staircase

Smart Railway System

When it comes to travelling, in our country the cheapest and the most comfortable mode of transport is railway. A lot of people in India travel to other places using railways and some people use Indian Railways to travel even on daily basis. So, a lot of people trust railways with their life on daily basis and if the railways are not secure and prone to accident then life of many people are at risk. A lot of railway accidents occur at level crossing that is the point of intersection of road and railway track and the reason in most of the cases in human error. So, to avoid the accidents caused due to human failure this model is to make level crossing unmanned and smart than can reduce the chances of accidents manifold. This model automatically closes the gates of railway crossing when the train is arriving near the crossing before a safe interval of time so that there is no chance of human error. After the train has passed the gates are again opened automatically to allow people to use the roadways again. Also, our model keeps a track of the train passed from the particular crossing along with exact time of passing so that the data is maintained that too without human effort. With the help of IR sensor and using GSM, information can be sent to the authorities (loco pilot) of the train if the track has any hindrance so that accident can be avoided as far as possible.

A Proposal for Smart Railway Station at Vadodara Junction

A Proposal for Smart Railway Station at Vadodara Junction