Operation Of High-speed Railway Research Articles

Modeling and Verification for Track Circuit Encoding in Train Control Center Based on UML and TA

The correct implementation of Train Control Center (TCC) software has great significance on the safe operation of high-speed railways. There are some problems in the currently used timed automata (TA) method for modeling TCC software, such as subjectivity and uncertainty in the modeling. In order to better verify the features of TCC software, this paper presents a new modeling method which combines Unified Modeling Language (UML) and Timed Automata (TA). As track circuit encoding function is a key function in TCC software, this paper takes it as an example to show the effectiveness of the proposed modeling method. Firstly, the UML class diagrams and state diagrams of TCC software were established based on the detailed analysis on TCC software. Secondly, the TA models are built according to the corresponding rules between UML and TA model. Finally, TA models were simulated and validated in the validation tool, UPPAAL. The simulation results show that TCC software can meets its functional requirements and performance requirements.

Service Planning System for Large-scale High Speed Railway Network

Due to its important role in high speed railway operation, service planning is always focused on by the researchers. With the development of computer technology, some systems have been researched to help operators and researchers to get satisfied service plan. The paper researches such a system for large-scale high speed railway network. It analyzes the main process of service planning firstly and presents the mainframe of the system based on the construction principle of multi-stages and multi-levels. The related key technologies are researched consequently. For highly applicable system control, a highly configurable system control method is put forward to control the runtime environment and optimizing process flexibly. Then a system construction technique based on multi-level loosely coupled bus and hierarchical control is proposed. The multi-granularity data management with strong constraints is also researched for the large-scale data management with complicated relationship. Finally, the demonstration of train service planning in multi-granularity is researched in order to provide strong and intelligent support for users’ decision from different views. The system has been developed by C#. Its feasibility and effectiveness have been proven by a sample of service planning for a network relative to Jinghu high speed railway.

Survey on High-Speed Railway Train Plan Design Issues

High-speed railway passenger train operation plan is an important basis to ensure the quality of transportation services. With construction and development of the country's high-speed railway, design and evaluation of railway passenger train plan theory need to be improved and perfected. On the basis of reading and studying a large amount of the references, this paper summarizes the domestic and overseas high-speed running railway operation modes, the high speed railway train operation programs design and other aspects. Besides, according to the related problems and shortcomings, this paper illustrates the meanings and necessities of analyzing the high-speed railway passenger train program.

High speed railway environment safety evaluation based on measurement attribute recognition model.

In order to rationally evaluate the high speed railway operation safety level, the environmental safety evaluation index system of high speed railway should be well established by means of analyzing the impact mechanism of severe weather such as raining, thundering, lightning, earthquake, winding, and snowing. In addition to that, the attribute recognition will be identified to determine the similarity between samples and their corresponding attribute classes on the multidimensional space, which is on the basis of the Mahalanobis distance measurement function in terms of Mahalanobis distance with the characteristics of noncorrelation and nondimensionless influence. On top of the assumption, the high speed railway of China environment safety situation will be well elaborated by the suggested methods. The results from the detailed analysis show that the evaluation is basically matched up with the actual situation and could lay a scientific foundation for the high speed railway operation safety.

Research on CRTSIII Ballastless Track Slab Cracks of High-Speed Railway

At present ballastless track has been widely applied to railway line for passenger in our country, therefore it has broad prospect. Cracks in ballastless track slabs are inevitable in the construction and operation of high-speed railway. Based on comprehensive investigation of documents, and taking cracks in ballastless track slabs as the main object, systematic and deep research has been done within this paper. The main research contents are as follows: First of all, the structure characteristics of CRTSIII ballastless track in high-speed railway are briefly introduced; Secondly, the paper mostly introduces the impacts what cracks make, the characteristics of cracks and how they form. Subsequently the paper introduces what are made to prevent cracks.

Train Detection by Magnetic Field Measurement with Giant Magnetoresistive Sensors for High-Speed Railway

Train detection, as part of the railway signaling system, is important for safe operation of high-speed railway. The recent flourishing development of high-speed railway stimulates the research need of train detection technology to enhance the safety and reliability of train operation. This paper proposes a new technique for train detection through magnetic field measurement by giant magnetoresistive sensors. This technology was studied by the analysis of magnetic field distribution in the high-speed rail system obtained from modeling and simulation. The results verify the feasibility for detection of train presence, number of rolling stocks, speed, and length. It can overcome the limitations of track circuits and provide additional measurement capabilities to the signaling system. This detection system can be built with low cost and minimal maintenance load as well as compacted construction. Therefore, it may serve as a new train detection system to help improve the current systems, enhancing and promoting the safety and reliability of high-speed rail system.

Delay Adjustment Method at Transfer Station of High-Speed Railway

Passenger transfer is one of the important research contents after the network operation of high-speed railway. Due to the high operation speed and high frequency, delays at transfer stations may occur frequently, leading to some potential safety problems. Main influence factors such as schedule time, transfer buffer time, waiting time, and delay time of delay and passengers classification during transfer were analyzed. A delay adjustment model of passengers at a transfer station was presented with minimal delay cost, waiting time cost, and adjustment cost as the optimization goal. Two adjustment strategies were proposed, including transfer passengers departure time adjustment and connecting trains departure time adjustment. And a delay adjustment algorithm at transfer station was designed for the optimal adjustment scheme. A case study proves the effectiveness of the method on optimal scheme design for passengers transferbased on the lowest delay cost of all passengers.

Competition between Wuhan-Guangzhou High-speed Railway and Civil Aviation Based on Disaggregate Model

With the operation of high-speed railways, the market share of air transportation has certain decrease, and there exist intense competitions between these two modes. Bases on the field data from the Wuhan-Guangzhou high-speed railway and the data from some air companies, this paper, develops a competition binary Logit model for Wuhan-Guangzhou high-speed rail and air transport with the non-set design model and relevant principles. The stated preference (SP) data are revised under revealed preference (RP) data, and the competition degree between high-speed railway and air transportation are measured by different air ticket price discount. The results indicate that when the ticket price discount of Wuhan-Guangzhou air is higher than 30%, there exist keen competitions between the high-speed railway and air transportation, and the higher the discount is the more competitions exist. This research is beneficial for balance the development of high-speed rail and air transportation and avoiding blind competitions of these two modes.

High-Speed Railway PFV Prediction Model Research Under Regional Economic Conditions

Under the regional economic conditions, a passenger flow prediction model is proposed in the paper. It can predict high-speed railway passenger flow volume under the conditions of multi-mode, and guide the reasonable operation of high-speed railway effectively. According to the data analysis of Beijing and Tianjin railway stations, we can know that the reasonable ticket price plays an important role in high-speed railway operation benefit under regional economic conditions.

A New Monitoring Method of Wheel/Rail Contact Forces Caused by Out-of-Round Railway Wheels

Traditional methods of wheel-rail contact forces measurement all need strain gauges on wheel sets or rails. The shortcomings of strain gauges such as zero-drift, poor anti-interference property and instability of test system can’t meat wheel/rail force test requirements in high-speed railways. A method based on PVDF piezoelectric sensing technology is presented for the test of wheel/rail contact force. Firstly, on the basis of the theory of vehicle-track coupling dynamics and by means of simulation software ADAMS/Rail, a three-dimensional train-track simulation model is established. Secondly, the modes and characteristics of wheel/rail impact vibrations due to non-roundness of railway wheels are investigated in high-speed railway operation. The relationship between the range for acceptable roundness values and vehicle speed is determined. Finally, the view that it is of important significance to establish wheel/rail force real-time monitoring system is expanded, so that abnormal conditions caused by out-of-round wheels can be detected in time, to ensure high-speed railway traffic safety. The study is very important for enhancing the stability and economy signification of rail transmission.

Operation and Organization Management of High-speed Railway in Japan

Under the background of the rapid development of high-speed railway in China, the paper analyzes the world's first operational high-speed railway—Japan Shinkansen to get a clear solution to the problems of the organization and management operations of high-speed railway. On the basis of actual operating data, the means and measures in organization and operational management of Japan Shinkansen are evaluated by horizontal and vertical comparison. And then, the paper makes the judgment to the related issues of the development of China's high-speed railway. Some conclusions are made, such as the development speed should not be too fast. The high-speed railway should be operated at the same railway station with the traditional railway with multi-parking program train. The competitive advantage within 600 km should be extensively explored. And it is essential to conduct scientific fare adjustment mechanism and put the energy consumption and emissions in the first place. The research provides reference for high-speed railway sustained and healthy development in China.

Optimization of target speeds of high-speed railway trains for traction energy saving and transport efficiency improvement

In the pursuit of higher operation speed at the passenger train services in China, the impacts of high-speed operation on energy consumption and transport efficiency are however not clearly identified. This research attempts to analyze the traction energy cost and transport operation time per 10,000 passenger-kilometers of high-speed railway (HSR) trains with a range of target speeds on certain HSR lines in China through a simulation approach. Having considered the effect of inter-stop transport distances, traction characteristics of HSR trains and gradients, curvatures, etc. of the rail lines, this study has deduced that the target speed of a HSR train for an inter-stop transport distance shorter than 100 km should be below 190 km/h from the perspectives of traction energy saving and transport efficiency improvement. Moreover, the study results also indicate that, unlike the actual HSR operation, the target speed should be dynamically adjusted according to the transport distances between stops if the transport capacity of the rail line is not extensively used. The exact target speed for each inter-stop transport distance shorter than 100 km should be further determined according to the traction characteristics of the train and the track geometry of the rail line.

Field investigations into the performance of magnetic track brakes of an electrical multiple unit against slippery tracks. Part 1: Adhesion improvement

Some rolling stock designed for conventional and high-speed railway operation has magnetic track brakes (MTBs) to have an additional brake independent of the wheel–rail adhesion to be mostly activated in emergency situations. In recent years, interest has grown in some railways towards the possible use of MTB against slippery tracks. However, there seems to be a lack of knowledge on the major benefits and possible side effects of using MTB to overcome low-adhesion conditions. This hinders the realization of a cost-benefit analysis to look at possible implementation. In order to contribute to a better understanding, field tests have been performed with the permanent MTB of an electrical multiple unit in a stabling yard. Low-adhesion conditions have been created by three types of contamination representative of slippery tracks, i.e. leaves, water, and grease. The entire work has been divided in two parts. In this Part I, emphasis is put on the adhesion recovery, in particular the benefit for subsequent wheel (or train) passages. Baseline tests (i.e. no use of MTB) have also been performed with water and leaves. Additionally, an adhesion improver widely used in the Dutch and British railways has also been tested with leaves to allow for a comparison in effectiveness with MTB under similar operating conditions. In each test, the wheel–rail adhesion conditions along the initially contaminated track have been measured to evaluate the adhesion improvement under the different testing conditions.

Study on Data Management of High-Speed Railway Transport Equipment Based on Metadata

Data platform of data sharing and service provide technical support for high-speed railway transportation organization, it provide data parameter and data support for high-speed railway operation management, and it plays an important role in promoting national economic development. In this paper, the metadata theory is used for data storage, data cataloging, data retrieval and data discovery in the management of the Beijing-Shanghai high-speed railway transportation equipment, analyze and propose key technologies of the establishment of data sharing platform based on metadata management of high-speed railway transportation equipment, correlation analysis is made and the result of analysis indicates that data platform can greatly improve the utilization and ability to obtain high-speed railway transportation equipment data. It can also improve the ability to support organizational decision-making of high-speed railway transportation.

A full-scale experimental and modelling study of ballast flight under high-speed trains

Recent experience with the operation of high-speed railways in the UK and elsewhere has revealed the phenomenon, termed ‘ballast flight’, of ballast particles becoming airborne during the passage of trains, potentially causing damage to both the railhead and the vehicle. This article reports the results of an investigation into the mechanical and aerodynamic forces acting on ballast particles that are generated during the passage of a high-speed train and addresses the question whether these might offer a possible explanation for the initiation of ballast flight. As the high-speed trains passed, measurements were made of the air pressure and velocity at various locations across the track, and of the velocity and acceleration of the track system (sleeper and rails) and the ballast itself. The aerodynamic forces exerted on a suspended ballast particle were also measured. An analytical model of the behaviour of small ballast particles was constructed to assist in the interpretation of the measured data. Analysis of the data and modelling suggest that neither mechanical forces nor aerodynamic forces in isolation are likely to be sufficient to initiate ballast flight under the conditions investigated, but that the phenomenon could arise from a combination of the two effects. It appears that the process is stochastic in nature: further work, with an increased number of measurements, is required to explore this.

Traction, forces, wheel climb and damage in high-speed railway operations

This paper summarizes the analysis of roughly 6 h of data from four instrumented wheelsets running at speeds of up to 240 km/h on the same Amtrak Acela trainset. Comparisons are made between power car and coach car traction values, L/ V ratio, and damage (wear and RCF). The propensity for wheel climb is found to be roughly the same for power car and coach car wheels. The wear and RCF damage, as evaluated through the Tγ index, is about 50% higher for the two power car wheelsets than for the two coach car wheelsets. The peak traction coefficient on the Amtrak system is measured to have a value of about 0.65 at low speeds, declining to about 0.22 at 200 km/h. These levels are much higher than those found in the literature for high-speed trains.

Evaluation of management strategies for the operation of high-speed railways in China

High-speed train (HST) operations have recently been introduced in rail passenger transportation markets worldwide. Although the technologies for such operations have levelled at speeds of around 300 km/h, the operating parameters to be adopted in each application will differ from country to country. The operating environment will be one of the crucial success factors for the implementation of HST operations in China. This paper compares three different management/ownership models which might be used in China. The paper analyzes the characteristics of each model and proposes an optimal plan of an operational system to develop HST operations in China by using a hierarchy goal achievement matrix approach.

Control and operation of tilting train services

Discussions on the best way forward to achieve reductions in journey time without the investment normally associated with the construction of new high-speed railways tend to concentrate on the technical issues to be resolved rather than on the very significant operational, legal and human issues that affect the economies of any high-speed railway operation. Many engineers and operators associated with long-established railway systems (1-4) view the introduction of tilting trains as the best way forward in situations where speed limits are imposed by track built with the objective of minimizing expenditure on civil works. Although there are instances where the introduction of tilting trains has yielded the benefits sought, there are many situations where the environment of the railway business effectively excludes this option. The author of the present paper has attempted to review the tilt debate from an operations angle, stimulated by some comments by Meyer (5), and focuses on developments in Great Britain.

Wheel/Rail Vertical Forces in High-Speed Railway Operation

The nature and magnitude of the vertical forces between a railway vehicle wheel and the rail at a dipped rail joint is investigated using methods developed by British Rail. The dependence of these forces on the unsprung weight is determined and a procedure is given for the specification of new equipment to insure that the principal wheel/rail forces at higher speeds will not exceed those of a reference vehicle at conventional speeds.