Trapped Vehicle Detection System for Four-Quadrant Gates in High Speed Rail Corridors: Design Methodology and Implementation Issues

1998 ◽  
Vol 1648 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Fred Coleman ◽  
Young J. Moon
Keyword(s):  
High Speed ◽  
Detection System ◽  
Vehicle Detection ◽  
High Speed Rail ◽  
Track System ◽  
The Status ◽  
System Functioning ◽  
Status Information ◽  
Four Quadrant ◽  
And Control

The objective of this paper is to determine the location of sensors in the track system functioning as checkpoints to provide information to a train on the status of the crossing and provide evasive maneuver time for the train and trapped vehicle. Two train-operating scenarios are evaluated: the first provides no deceleration when a trapped vehicle is detected; the second scenario has the train decelerate at a tolerable deceleration rate to passengers when a trapped vehicle is detected. The findings indicate that there is a trade-off between minimizing the distances to locate the trapped vehicle detection sensors in the track system and potential issues of reliability of vehicle detection and maximization of safety. Recommendations include provision of on-board real-time status information on the crossing(s) in the train with automatic train location and control to continuously provide safe stopping distances in event of a trapped vehicle.

Illinois High-Speed Rail Four-Quadrant Gate Reliability Assessment

2010 ◽  
Author(s):  
Adrian Hellman ◽  
Tashi Ngamdung
Keyword(s):  
High Speed ◽  
Vehicle Detection ◽  
The United States ◽  
Transportation Systems ◽  
Innovative Technology ◽  
United States Department ◽  
High Speed Rail ◽  
Grade Crossings ◽  
Four Quadrant ◽  
The Impact

The United States Department of Transportation’s (USDOT) Research and Innovative Technology Administration’s John A. Volpe National Transportation Systems Center (Volpe Center), under the direction of the USDOT Federal Railroad Administration (FRA) Office of Research and Development (ORD), conducted a reliability analysis of the four-quadrant gate/vehicle detection equipment installed on the potential high-speed rail (HSR) corridor between Chicago and St Louis. A total of 69 highway-rail grade crossings on a 121-mile (195 km) segment of the 280-mile corridor were equipped with four-quadrant gates and inductive loop vehicle detection technology. This segment, between Mazonia and Springfield Illinois, may eventually carry passenger trains at speeds up to 110 mph (177 km/h), including at many of the highway-rail grade crossings. The analysis was based on maintenance records obtained from the Union Pacific Railroad (UPRR), the owner and operator of the rail line. The results were used to assess the impact of the equipment reliability on the proposed HSR timetable. The Volpe Center study showed that the total average delay to the five scheduled daily high-speed passenger roundtrips was an estimated 10.5 minutes, or approximately one minute per train. Overall, extensive analysis of the trouble ticket data showed that the four-quadrant gate and vehicle detection equipment had a minimal direct impact on the frequency and duration of grade crossing malfunctions.

Design of Gate Delay and Gate Interval Time for Four-Quadrant Gate System at Railroad-Highway Grade Crossings

1996 ◽  
Vol 1553 (1) ◽  
pp. 124-131 ◽  
Author(s):  
Fred Coleman ◽  
oung J. Moon
Keyword(s):  
High Speed ◽  
Signalized Intersections ◽  
Design Approach ◽  
Gate Delay ◽  
High Speed Rail ◽  
Interval Time ◽  
Signal Change ◽  
Gate System ◽  
Grade Crossings ◽  
Four Quadrant

A design methodology for gate delay and gate interval time for at-grade crossings using four-quadrant gates is developed. The design approach is based on the concept of dilemma zones related to signal change intervals at signalized intersections. The design approach is validated based on data from six sites in Illinois on a proposed high-speed rail corridor. Gate delay and gate interval times are determined that provide an optimal safe decision point to allow a driver to stop before the crossing or to proceed through the crossing without becoming trapped by the exit gates.

High Speed Rail: Track Construction Considerations

2011 ◽  
Author(s):  
Blaine O. Peterson
Keyword(s):  
High Speed ◽  
Optimal Solution ◽  
Rolling Stock ◽  
High Speed Rail ◽  
Track Geometry ◽  
Slab Track ◽  
Passenger Rail ◽  
Construction Methods ◽  
Track System ◽  
Ballasted Track

This paper discusses general High Speed Rail (HSR) track geometry, construction and maintenance practices and tolerances. The discussion will reference several key international projects and highlight different construction methods and the track geometry assessments used to establish and ensure serviceability of a typical HSR system. Historically, established tighter tolerances of “Express” HSR (i.e. operating speeds greater than 240 km/h or 150 mph) systems have favored the use of slab track systems over ballasted track systems. Slab track systems offer greater inherent stability while ballasted track systems generally require more frequent track geometry assessments and anomaly-correcting surfacing operations. The decisions related to which system to use for a given application involve numerous considerations discussed only briefly in this paper. In many cases, the optimal solution may include both track forms. Rolling stock considerations and their influence on track infrastructure design are considered beyond the scope of this paper. This paper will focus predominantly on two slab track systems widely used in international HSR projects: the Japanese J-slab track system; and the German Rheda slab track system. The French track system will be referenced as the typical ballasted track HSR design. The practices discussed in this paper generally apply to systems which are either primarily or exclusively passenger rail systems. In the U.S., these types of systems will necessarily exclude the systems the Federal Railway Administration (FRA) refers to as “Emerging” or “Regional” HSR systems which include passenger train traffic to share trackage on, what are otherwise considered, primarily freight lines.

Moving element analysis of discretely supported high-speed rail systems

2017 ◽  
Vol 232 (3) ◽  
pp. 783-797 ◽  
Author(s):  
Jian Dai ◽  
Kok Keng Ang ◽  
Minh Thi Tran ◽  
Van Hai Luong ◽  
Dongqi Jiang
Keyword(s):  
High Speed ◽  
Railway Track ◽  
High Speed Train ◽  
Element Analysis ◽  
High Speed Rail ◽  
Mass System ◽  
Rail System ◽  
Rail Systems ◽  
Track System ◽  
The Difference

In this paper, a computational scheme in conjunction with the moving element method has been proposed to investigate the dynamic response of a high-speed rail system in which the discrete sleepers on the subgrade support the railway track. The track foundation is modeled as a beam supported by uniformly spaced discrete spring-damper units. The high-speed train is modeled as a moving sprung-mass system that travels over the track. The effect of the stiffness of the discrete supports, train speed, and railhead roughness on the dynamic behavior of the train–track system has been investigated. As a comparison, the response of a continuously supported high-speed rail system that uses a foundation stiffness equivalent to that of a discretely supported track has been obtained. The difference in results between the “equivalent” continuously supported and the discretely supported high-speed rails has been compared and discussed. In general, the study found that a high-speed train that travels over a discretely supported track produces more severe vibrations than that travels over a continuously supported track of equivalent foundation stiffness.

scholarly journals Analysis of Rail Corrugation Characteristics on High-Speed Rail Based on Transient Finite Element Method

2021 ◽  
Vol 26 (3) ◽  
pp. 231-239
Author(s):  
Zhiqiang Wang ◽  
Zhenyu Lei
Keyword(s):  
High Speed ◽  
Vertical Vibration ◽  
Dynamic Responses ◽  
High Speed Rail ◽  
Relative Slip ◽  
Tangential Contact ◽  
Rail Corrugation ◽  
Track System ◽  
Characteristic Wavelength ◽  
Unbalanced Load

By using the transient finite element method, a three-dimensional wheelset-track coupled rolling contact model for high-speed rail is established, and the rationality and effectiveness of the model are verified by field measurements. Next, the wheel-rail contact stress states and relative slip characteristics are calculated and analyzed to reveal the cause of inner rail corrugation. Then, the vertical vibration acceleration of the rail/wheel is taken as the output variable to study the dynamic responses of the wheelset-track system. Finally, the parameter sensitivity analysis is carried out. The results show that the maximum normal/tangential contact stress between the inner wheel and inner rail is greater than that between outer wheel and outer rail due to the unbalanced load of inner rail caused by the excess superelevation of track structure, which indicates that the unbalanced load of the inner rail may aggravate the development of rail wear, and the rationality of the model established in this paper is verified. The wheel-rail relative slip region on the inner rail side appears periodically, and the distance between the two adjacent slip regions is close to the characteristic wavelength of the measured inner rail corrugation, which illustrates that the periodic variation of slip regions on the inner rail surface plays an important role in the formation of rail corrugation, and the validity of the model is verified. The periodic distribution of wheel-rail relative slip regions on the outer rail surface is not obvious, demonstrating that the outer rail tends to form uniform wear, which is consistent with the fact that the outer rail corrugation is slight in the measured section. The wheelset-track system has been in the process of unstable continuous oscillation in the analysis interval, combined with the analysis results of the wheel-rail relative slip characteristics, it can be concluded that the unstable self-excited vibration of wheelset-track system under the condition of tangential contact force reaching saturation is the main cause of rail corrugation. The dominant characteristic frequencies of vertical vibration accelerations of rail and wheel are all 561 Hz, the corresponding characteristic wavelength (148 mm) is close to the distance (150 mm) between the calculated adjacent slip regions, and is also close to the characteristic wavelengths (125 mm and 160 mm) of inner rail corrugation, which shows that the resonance phenomenon occurs in the wheelset-track system at the above frequency, thus leading to the increase of dynamic responses of wheelset-track system. The fastener vertical stiffness and wheel-rail coefficient of friction have significant effect on the development of rail corrugation, and the running speed determines the occurrence probability of inner/outer rail corrugation by affecting the track superelevation state.

Train delay propagation under random interference on high-speed rail network

2019 ◽  
Vol 30 (08) ◽  
pp. 1950059
Author(s):  
Ziyan Feng ◽  
Chengxuan Cao ◽  
Yutong Liu
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Sensitivity Analyses ◽  
High Speed Rail ◽  
Control Policies ◽  
Passenger Train ◽  
Delay Propagation ◽  
Rail Network ◽  
Railway Traffic ◽  
And Control

To simulate passenger train movements on the high-speed rail network, this paper proposes a new dynamic model based on the discrete time method and provides some efficient control policies correspondingly. Besides that, an improved minimum safe headway in the moving-block system on the high-speed rail network is presented. Using the proposed method, the dynamic characteristics of railway traffic flow are analyzed under random interferences on the high-speed rail network. Then, some sensitivity analyses are implemented to investigate the propagation features of delays under different interferences. The results indicate that the proposed dynamic model and control policies for the passenger train movements on the high-speed rail network are effective and can be a fundamental research for subsequent research of delay propagation, rerouting and rescheduling problems.

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

2013 ◽  
Vol 284-287 ◽  
pp. 2102-2114 ◽  
Author(s):  
Shu Qi Zhang ◽  
Wing Kin Lee ◽  
Philip W.T. Pong
Keyword(s):  
Magnetic Field ◽  
Field Measurement ◽  
High Speed ◽  
Detection System ◽  
Magnetic Field Measurement ◽  
Signaling System ◽  
High Speed Rail ◽  
High Speed Railway ◽  
Rail System ◽  
Safety And Reliability

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.

scholarly journals Moving element analysis of high-speed rail system accounting for hanging sleepers

2018 ◽  
Vol 148 ◽  
pp. 05007 ◽  
Author(s):  
Jian Dai ◽  
Kok Keng Ang ◽  
Dongqi Jiang
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
High Speed Train ◽  
Train Track ◽  
Element Analysis ◽  
High Speed Rail ◽  
Factors Affecting ◽  
Rail System ◽  
Track System ◽  
Ballasted Track

It is very common in the ballasted track system that sleepers are not well supported by the ballast materials due to the uneven settlement of the ballast under repeated train passage. These unsupported track elements are often termed as hanging sleepers and they can lead to undesirable effects due to increased dynamic response of the train-track system, especially when the speed of the train is high. In this paper, we present a computation scheme in conjunction with the moving element method for the analysis of high-speed train-track dynamics accounting for hanging sleepers. The proposed computational scheme will be first verified by comparison with available analytical results. The dynamic response of a high-speed train traveling on a ballasted track considering unsupported sleepers is next investigated. Various factors affecting the response of the high-speed rail system including the speed of the train, the number of hanging sleepers and the pattern of the hanging sleepers will be examined and discussed.

Dynamic Response of High-Speed Train-Track System Due to Unsupported Sleepers

2018 ◽  
Vol 18 (10) ◽  
pp. 1850122 ◽  
Author(s):  
Jian Dai ◽  
Kok Keng Ang ◽  
Dongqi Jiang ◽  
Van Hai Luong ◽  
Minh Thi Tran
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Numerical Study ◽  
Computational Scheme ◽  
The Finite Element Method ◽  
High Speed Rail ◽  
Factors Affecting ◽  
Track System ◽  
Three Phase ◽  
Element Method

This paper is concerned with a numerical study on the dynamic response of a high-speed rail (HSR) system subjected to unsupported sleepers using the moving element method (MEM). A three-phase computational scheme in conjunction with the MEM is proposed to account for the motion of the unsupported sleepers in relation to the truncated rail segment in the moving coordinate system. The accuracy of the proposed computational scheme is examined by comparison with available analytical results in the literature and against the finite element method using commercial software. A parametric study is conducted using a computational model consisting of a 10-degree of freedom train model and a three-layer ballasted track model to investigate the effect of unsupported sleepers on the dynamic response of the HSR system. Various factors affecting the response of the HSR system, including the speed of the train, the number of unsupported sleepers and the distance between the unsupported sleepers, are examined and discussed.

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