scholarly journals A Prognostic Framework for Wheel Treads Integrating Parameter Correlation and Multiple Uncertainties

2020 ◽  
Vol 10 (2) ◽  
pp. 467 ◽  
Author(s):  
Guifa Huang ◽  
Yu Zhao ◽  
Han Wang ◽  
Xiaobing Ma ◽  
Deyao Tang
Keyword(s):  
High Speed ◽  
Process Model ◽  
Quantitative Relationship ◽  
Model Parameters ◽  
Accuracy Improvement ◽  
Safety Risks ◽  
Proposed Model ◽  
Effective Technology ◽  
High Speed Trains ◽  
Multiple Uncertainties

As crucial rotary components of high-speed trains, wheel treads in realistic operation environment usually suffer severe cyclic shocks, which damage the health status and ultimately cause safety risks. Timely and precise health prognosis based on vibration signals is an effective technology to mitigate such risks. In this work, a new parameter-related Wiener process model is proposed to capture multiple uncertainties existed in on-site prognosis of wheel treads. The proposed model establishes a quantitative relationship between degradation rate and variations, and integrates uncertainties via heterogeneity analysis of both criterions. A maximum-likelihood-based method is presented to initialize the unknown model parameters, followed by a recursive update algorithm with fully utilization of historical lifetime information. An investigation of real-world wheel tread signals demonstrates the superiority of the proposed model in accuracy improvement.

SIMPLIFIED DYNAMIC MODEL FOR HIGH-SPEED CHECKWEIGHER

2013 ◽  
Vol 24 ◽  
pp. 1360036 ◽  
Author(s):  
YUJI YAMAKAWA ◽  
TAKANORI YAMAZAKI
Keyword(s):  
Dynamic Model ◽  
Measurement System ◽  
High Speed ◽  
Mass Measurement ◽  
Conveyor Belt ◽  
Open Loop ◽  
Model Parameters ◽  
Proposed Model ◽  
Control Scheme ◽  
Mass Damper

In this paper, we concern with the dynamic behaviors of a high speed mass measurement system with conveyor belt (a checkweigher). The goal of this paper is to construct a simple model of the measurement system so as to duplicate a response of the system. The checkweigher with electromagnetic force compensation can be approximated by the combined spring-mass-damper systems as the physical model, and the equation of motion is derived. The model parameters (a damping coefficient and a spring constant) can be obtained from the experimental data for open-loop system. Finally, the validity of the proposed model can be confirmed by comparison of the simulation results with the realistic responses. The simple dynamic model obtained offers practical and useful information to examine control scheme.

scholarly journals Influence of Posture Change on Train Running Safety under Crosswind

2021 ◽  
Vol 11 (13) ◽  
pp. 6067
Author(s):  
Jian Yan ◽  
Tefang Chen ◽  
Shu Cheng ◽  
E Deng ◽  
Weichao Yang ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Aerodynamic Load ◽  
Lateral Direction ◽  
Running Safety ◽  
Derailment Coefficient ◽  
Safety Risks ◽  
High Speed Trains ◽  
Computational Fluid Dynamics Cfd

High-speed trains serving in a crosswind region are bearing more significant safety risks. Based on the three-dimensional (3D) Unsteady Reynolds-Averaged Navier–Stokes (URANS) turbulence model, a Computational Fluid Dynamics (CFD) computational work was conducted in the present study to predict the transient aerodynamic load of the train. The transient aerodynamic load was then employed as the input of the dynamic system to perform a dynamic analysis of running safety. Noticeable changes in the aerodynamic coefficients were found when the train entered and left the crosswind region due to the dramatic change in flow patterns. The original posture also provided significant changes to the train’s aerodynamic responses. A slightly larger maximum derailment coefficient was found on the first bogie of the leading car with a preset posture. There were obvious differences in the displacement characteristics of the three cars in the lateral direction and the rolling rotation, and the magnitude of the posture changes decreased from the leading car to the trailing car. The train with the consideration of posture was proven to withstand weaker crosswinds.

Rigid-Mass Vehicle Model for Identification of Bridge Frequencies Concerning Pitching Effect

2019 ◽  
Vol 19 (02) ◽  
pp. 1950008 ◽  
Author(s):  
Judy P. Yang ◽  
Bo-Lin Chen
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Vehicle Body ◽  
Moving Loads ◽  
Vehicle Model ◽  
Test Vehicle ◽  
Single Degree Of Freedom ◽  
Proposed Model ◽  
High Speed Trains ◽  
Rigid Mass

The concept of vehicle-bridge interaction (VBI) was originally developed to investigate the dynamic behavior of bridges subjected to moving loads such as high-speed trains. In recent years, the VBI system was introduced to further explore the possibility of identifying bridge frequencies in order to monitor the health of bridges via the use of passing vehicles. Among the models of test vehicles, the sprung mass vehicle model with a single-degree-of-freedom vehicle body is the most common adopted one due to its simplicity. Nevertheless, for a test vehicle moving over the uneven pavement, the pitching effect arising from the vertical and rotational movements of the vehicle actually influences the identification of bridge frequencies. As such, a rigid-mass vehicle model is proposed in this work to improve the sprung mass vehicle model by including both vertical and rotational deflections. The analytical solutions to the rigid-mass VBI system are derived to verify the proposed model, and the numerical examples are provided to investigate the dynamic behavior of the VBI system subjected to road irregularity.

Vibration analysis of the axle bearings considering the combined errors for a high-speed train

2020 ◽  
Vol 234 (3) ◽  
pp. 481-497
Author(s):  
Jing Liu ◽  
Xinbin Li ◽  
Wennian Yu
Keyword(s):  
High Speed ◽  
Error Model ◽  
Manufacturing Processes ◽  
High Speed Train ◽  
The Road ◽  
Critical Elements ◽  
Proposed Model ◽  
Manufacturing Errors ◽  
High Speed Trains ◽  
Track Irregularities

Axle bearings are critical elements of high-speed trains. Although the quality and precision of axle bearings have been significantly improved, the manufacturing errors, such as the roundness and waviness errors, cannot be eliminated during their manufacturing processes. The axle bearings with the roundness and waviness errors have great influences on vibration performances of the high-speed trains. To obtain an in-depth understanding of the vibrations caused by the axle bearing with the combined errors considering both the roundness and waviness errors. This work conducts an improved analytical model for a high-speed train considering the axle bearings with the combined errors, which cannot be formulated by the previous train model considering single roundness or waviness errors. The combined errors are defined to include both the roundness and waviness errors. A new multiple cosine function is presented to model the combined errors. The time-depended force excitations produced by the combined errors are also considered in the dynamic model. A track irregularities model is utilized to formulate the road spectrum displacement excitations from the rail and roadbed. The influences of the error amplitude and order on the vibrations of high-speed train are analyzed. The results for the single roundness error model, single waviness error model, and combined errors model are compared to represent the superiority of proposed model. It depicts that this work can provide a more reasonable analytical method for understanding the vibrations of high-speed train considering the axle bearings with the combined manufacturing errors compared to the reported single error models.

Experimental Study on the Ballast Pick-Up Problem in High Speed Trains

2010 ◽  
Author(s):  
Fermin Navarro-Medina ◽  
Angel Sanz-Andres ◽  
Isabel Perez-Grande
Keyword(s):  
Theoretical Model ◽  
High Speed ◽  
Experimental Results ◽  
Wind Gust ◽  
Experimental Facility ◽  
Proposed Model ◽  
Theoretical Predictions ◽  
High Speed Trains ◽  
Train Speed

A new theoretical approach on the determination of the conditions for the initiation of the motion of the ballast stones due to the wind gust created under the high-speed trains has been recently developed (Sanz-Andres & Navarro-Medina, 2009). This determination is critical to predict the starting of ballast pick-up, because once the motion is initiated a saltation-like chain reaction could take place. Sometimes the flying stones reach an height which is larger than the lowest parts of the train, striking them (and the track surroundings) producing considerable damage that are to be avoided e.g. by limiting the maximum allowed operational train speed. The aim of this contribution is to present the experimental results that have been obtained to check the validity of the proposed model. The experimental facility is a wind tunnel, with a gust generator, with a maximum wind speed of some 20 m/s (65.6 ft/s) and 10 Hz gust frequency. The test section is 0.39 m × 0.54 m (15.4 in × 21.3 in), which is suitable to perform experiments with stone models. It is shown that in the range of parameters explored, the experimental results are in good agreement with the theoretical model predictions. In this contribution the theoretical model is summarized, the experimental facility is described, showing some of its typical performances, the experimental procedure is outlined, and the experimental results are compared with the theoretical predictions.

scholarly journals Research on Passenger Flow Assignment of High-Speed Trains Based on Personalized Itinerary Choice

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Jinzi Zheng
Keyword(s):  
High Speed ◽  
Ticket Sale ◽  
Passenger Flow ◽  
Assignment Method ◽  
Assignment Model ◽  
Proposed Model ◽  
Flow Assignment ◽  
High Speed Trains ◽  
Time Minimization ◽  
Passenger Flow Assignment

Under the condition that ticket fare for high-speed train could fluctuate around a benchmark price in China, aimed at predicting how the passengers will distribute among different trains given a ticket fare, the passenger flow assignment method for high-speed trains is studied. Different from the classical researches on the passenger flow assignment, by introducing a variable that represents the value of time, this research allows passengers to make their personalized choice between the principles of time minimization and expense minimization, so as to demonstrate how the passengers holding different time values respond to each ticket fare scheme. An equilibrium passenger flow assignment model based on personalized choice is built and an improved Monte-Carlo random simulation algorithm is designed for solving the model. The actual ticket sale data for Beijing-Shanghai high-speed railway are used to verify the feasibility of the proposed model and algorithm. The passenger flow assignment results under various fare schemes show how the distribution of passenger flow changes with the adjustment of ticket fare.

scholarly journals Model-Independent Adaptive Fault-Tolerant Tracking Control for High-Speed Trains with Actuator Saturation

2019 ◽  
Vol 9 (19) ◽  
pp. 4146 ◽  
Author(s):  
Chuanfang Xu ◽  
Xiyou Chen ◽  
Lin Wang
Keyword(s):  
Tracking Control ◽  
High Speed ◽  
Actuator Saturation ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Upper Bounds ◽  
Model Parameters ◽  
Actuator Faults ◽  
High Speed Trains ◽  
Model Independent

This paper investigates the fault-tolerant tracking control problem of high-speed trains (HSTs) subject to unknown model parameters with unavailable uncertainties, unmeasurable additional disturbance, and unpredictable actuator faults constrained by actuator saturation. An adaptive passive fault-tolerant tracking control strategy based on variable-gain proportion-integral-derivative (PID)-type sliding mode surface is proposed to handle the problem. Unknown model parameters, gains of the PID-type sliding mode surface, and upper bounds of the lumped system uncertainty which includes additional disturbance, modeling uncertainties, and uncertainties resulting from actuator faults, are estimated online by adaptive technology. The input saturation (actuator output saturation) constraint is handled by introducing an auxiliary signal. The proposed controller can compensate for the effects of the lumped uncertainty and the actuator faults effectively. Moreover, the controller is model-independent, which means it requires no prior knowledge of model parameters and upper bounds of the lumped uncertainty, and does not depend upon fault detection and diagnosis module. The asymptotic stability of the closed-loop train system is demonstrated by Lyapunov theory. Good fault-tolerant tracking capacity, effective anti-actuator saturation ability, and strong robustness of the proposed controller are verified via numerical simulation.

Battery Self-Traction System for High-Speed Trains

2020 ◽  
Vol 140 (5) ◽  
pp. 349-355
Author(s):  
Hirokazu Kato ◽  
Kenji Sato
Keyword(s):  
High Speed ◽  
High Speed Trains ◽  
Traction System

In-Plane Flexible Ring Tire Model—Part 1: Modeling and Parameter Identification

2018 ◽  
Vol 46 (3) ◽  
pp. 174-219 ◽  
Author(s):  
Bin Li ◽  
Xiaobo Yang ◽  
James Yang ◽  
Yunqing Zhang ◽  
Zeyu Ma
Keyword(s):  
Static Load ◽  
Model Parameters ◽  
Tire Model ◽  
Test Results ◽  
Lumped Mass ◽  
Virtual Test ◽  
Proposed Model ◽  
Particle Swarm Method ◽  
Vehicle Dynamic Simulation ◽  
Flexible Ring

ABSTRACT The tire model is essential for accurate and efficient vehicle dynamic simulation. In this article, an in-plane flexible ring tire model is proposed, in which the tire is composed of a rigid rim, a number of discretized lumped mass belt points, and numerous massless tread blocks attached on the belt. One set of tire model parameters is identified by approaching the predicted results with ADAMS® FTire virtual test results for one particular cleat test through the particle swarm method using MATLAB®. Based on the identified parameters, the tire model is further validated by comparing the predicted results with FTire for the static load-deflection tests and other cleat tests. Finally, several important aspects regarding the proposed model are discussed.

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