Virtual-Coupling Operation for High-Speed Rail based on Following- Train Speed Profile Optimization

2021 ◽  
Author(s):  
Bin Xu ◽  
Chaoxian Wu ◽  
Shaofeng Lu ◽  
Fei Xue
Keyword(s):  
High Speed ◽  
Speed Profile ◽  
High Speed Rail ◽  
Virtual Coupling ◽  
Train Speed ◽  
Profile Optimization

scholarly journals A Numerical Study of the Screening Effectiveness of Open Trenches for High-Speed Train-Induced Vibration

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Chih-hung Chiang ◽  
Pei-hsun Tsai
Keyword(s):  
Poisson’S Ratio ◽  
High Speed ◽  
Numerical Study ◽  
Cutoff Frequency ◽  
Poisson's Ratio ◽  
High Speed Train ◽  
High Speed Rail ◽  
Train Speed ◽  
Open Trench ◽  
Screening Effectiveness

This study used the 2D boundary element method in time domain to examine the screening effectiveness of open trenches on reducing vibration generated by a high-speed train. The parameters included configurations of the trench, train speed, the distance between the source and the trench, and the Poisson’s ratio of the soil. A reducing displacement level (in dB scale) was defined and used to evaluate the screening effectiveness of a wave barrier. The maximal reducing displacement level reached 25 dB when an open trench was used as a wave barrier. The depth of an open trench is a main influential parameter of screening effectiveness. The cutoff frequency of the displacement spectrum increases with decreasing trench depth. The maximal screening effectiveness occurs when the depth is 0.3-0.4 Rayleigh wavelength. Using an open trench as a wave barrier can reduce 10–25 dB of vibration amplitude at frequencies between 30 and 70 Hz. A considerable increase in screening effectiveness of the open trench was observed from 30 to 70 Hz, which matches the main frequencies of vibration induced by Taiwan High Speed Rail. The influence of trench width on screening effectiveness is nonsignificant except for frequencies from 30 to 40 Hz. Poisson’s ratio has various effects on the reduction of vibration at frequencies higher than 30 Hz.

scholarly journals Discrete Train Speed Profile Optimization for Urban Rail Transit: A Data-Driven Model and Integrated Algorithms Based on Machine Learning

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Kang Huang ◽  
Jianjun Wu ◽  
Xin Yang ◽  
Ziyou Gao ◽  
Feng Liu ◽  
...  
Keyword(s):  
Machine Learning ◽  
Energy Consumption ◽  
Urban Rail Transit ◽  
Data Driven ◽  
Support Vector ◽  
Rail Transit ◽  
Speed Profile ◽  
Urban Rail ◽  
Train Speed ◽  
Profile Optimization

Energy-efficient train speed profile optimization problem in urban rail transit systems has attracted much attention in recent years because of the requirement of reducing operation cost and protecting the environment. Traditional methods on this problem mainly focused on formulating kinematical equations to derive the speed profile and calculate the energy consumption, which caused the possible errors due to some assumptions used in the empirical equations. To fill this gap, according to the actual speed and energy data collected from the real-world urban rail system, this paper proposes a data-driven model and integrated heuristic algorithm based on machine learning to determine the optimal speed profile with minimum energy consumption. Firstly, a data-driven optimization model (DDOM) is proposed to describe the relationship between energy consumption and discrete speed profile processed from actual data. Then, two typical machine learning algorithms, random forest regression (RFR) algorithm and support vector machine regression (SVR) algorithm, are used to identify the importance degree of velocity in the different positions of profile and calculate the traction energy consumption. Results show that the calculation average error is less than 0.1 kwh, and the energy consumption can be reduced by about 2.84% in a case study of Beijing Changping Line.

scholarly journals Energy-Efficient Speed Profile Optimization for High-Speed Railway Considering Neutral Sections

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 25090-25100
Author(s):  
Zhang Bin ◽  
You Shijun ◽  
Zhang Lanfang ◽  
Li Daming ◽  
Chen Yalan
Keyword(s):  
Energy Efficient ◽  
High Speed ◽  
Speed Profile ◽  
High Speed Railway ◽  
Profile Optimization

scholarly journals Iterative Learning-Based Path and Speed Profile Optimization for an Unmanned Surface Vehicle

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 439 ◽  
Author(s):  
Yang Yang ◽  
Quan Li ◽  
Junnan Zhang ◽  
Yangmin Xie
Keyword(s):  
Vehicle Dynamics ◽  
High Speed ◽  
Measurement Accuracy ◽  
Learning Algorithm ◽  
Path Following ◽  
Iterative Learning ◽  
Speed Profile ◽  
Hydrographic Survey ◽  
Turning Radius ◽  
Profile Optimization

Most path-planning algorithms can generate a reasonable path by considering the kinematic characteristics of the vehicles and the obstacles in hydrographic survey activities. However, few studies consider the influence of vehicle dynamics, although excluding system dynamics may considerably damage the measurement accuracy especially when turning at high speed. In this study, an adaptive iterative learning algorithm is proposed to optimize the turning parameters, which accounts for the dynamic characteristics of unmanned surface vehicles (USVs). The resulting optimal turning radius and speed are used to generate the path and speed profiles. The simulation results show that the proposed path-smoothing and speed profile design algorithms can largely increase the path-following performance, which potentially can help to improve the measurement accuracy of various activities.

Vertical Dynamic Response of High-Speed Rails During Sudden Deceleration

2017 ◽  
Vol 14 (02) ◽  
pp. 1750014 ◽  
Author(s):  
Minh Thi Tran ◽  
Kok Keng Ang ◽  
Van Hai Luong
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Computational Study ◽  
Railway Track ◽  
Contact Theory ◽  
High Speed Rail ◽  
Nonlinear Contact ◽  
Train Speed ◽  
Euler Bernoulli Beam ◽  
Two Parameter

In this paper, a computational study using the moving element method is carried out to investigate the dynamic response of a high-speed rail (HSR) experiencing sudden braking. The train is modeled as a 10-DOF system of interconnected spring-damping units. The Hertz contact theory is employed to account for the nonlinear contact force between the wheel and rail. The railway track is treated as an Euler–Bernoulli beam resting on a two-parameter elastic damped foundation. The effects of wheel sliding, initial train deceleration, initial train speed and the severity of railhead roughness on the dynamic response of the HSR are investigated.

Dynamic response of soft soils in high-speed rail foundation: in situ measurements and time domain finite element method model

2019 ◽  
Vol 56 (12) ◽  
pp. 1832-1848 ◽  
Author(s):  
Yiqun Tang ◽  
Qi Yang ◽  
Xingwei Ren ◽  
Siqi Xiao
Keyword(s):  
Dynamic Response ◽  
Time Domain ◽  
High Speed ◽  
In Situ Measurements ◽  
Vertical Acceleration ◽  
High Speed Rail ◽  
Foundation Soil ◽  
Train Speed ◽  
The Time Domain

The dynamic response of soil to vibrations induced by moving trains has been widely studied using in situ measurements. However, few in situ tests have been conducted to measure the resulting vibration of foundation soils, especially for the foundation of high-speed rail (HSR) in a soft area. In this study, a number of field experiments were conducted on Shanghai–Hangzhou HSR in a suburb of Shanghai, China. The testing instruments were installed in foundation soils just beneath the HSR track to measure the vibration induced by trains moving at different speeds. Test results show the frequencies of foundation soil vibration are characterized by the train speed and geometrical features of the trains and slab track. In the frequency domain, the dominant frequency bands for vertical acceleration, velocity, and displacement of foundation soil decrease successively. In the time domain, the magnitudes of vibration levels at different locations in a soil foundation decrease gradually with increasing distance from the track. Furthermore, higher train speed can result in higher vibration level. Based on the field conditions, a three-dimensional dynamic finite–infinite element model is developed in the time domain. It shows the model is capable of capturing the primary characteristics of train-induced vibration in the field.

Dynamic response of high-speed rails due to heavy braking

2016 ◽  
Vol 231 (6) ◽  
pp. 701-716 ◽  
Author(s):  
Minh Thi Tran ◽  
Kok Keng Ang ◽  
Van Hai Luong
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Static Friction ◽  
Railway Track ◽  
High Speed Rail ◽  
Track Condition ◽  
Braking Torque ◽  
Train Speed ◽  
Torque Coefficient ◽  
Euler Bernoulli Beam

The dynamic response of a high-speed rail experiencing heavy braking is investigated using the moving element method. Possible sliding of train wheels over the rails as the train decelerates is accounted for. The train is modelled as a 14-DOF system comprising a car body, bogies and wheel sets interconnected by spring-damping units. The railway track is modelled as an infinite Euler–Bernoulli beam resting on a two-parameter elastic-damped foundation. A convected coordinate system attached to the moving train is employed in the formulation of the governing equations. The effects of braking torque, coefficient of static friction between wheels and rail, initial train speed and the severity of railhead roughness (track irregularity) on the dynamic response of the high-speed rail, including the occurrence of the ‘jumping wheel’ phenomenon, are examined. The phenomenon describes the momentary loss of contact between the wheel and track. A combination of high braking torque, large static friction coefficient, high initial train speed and severe track condition promotes larger dynamic effects.

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