Optimization on Resource-Constrained Multi-Project Scheduling of Electric Multiple Unit Overhaul

2013 ◽  
Vol 748 ◽  
pp. 457-462
Author(s):  
Peng Sun ◽  
Tian Yun Shi ◽  
Wei Jiao Zhang
Keyword(s):  
High Speed ◽  
Regular Production ◽  
High Speed Trains ◽  
Business Requirement ◽  
Multiple Unit ◽  
Dynamic Resource ◽  
Task Splitting ◽  
And Performance ◽  
Soft Precedence Constraints ◽  
Multiple Units

As the numbers and running distance of Chinese high-speed trains increase, many electric multiple units (EMU) gradually enter into overhaul stage, EMU maintenance bases face challenges of transition from practical exploration, regular production to lean production. In accordance of business requirement, built a model of dynamic resource allocation, task splitting, and soft precedence constraints. By the design of nonlinear decline inertia weight factor, a refined particle swarm optimization (PSO), as well as the corresponding parallel transformation scheme from particle to schedule, is presented. Finally, computational analysis is performed to validate the model and algorithm on optimization capabilities, resource utilization and performance.

scholarly journals Effect of the turning characteristics of underfloor wheel lathes on the evolution of wheel polygonisation

2018 ◽  
Vol 233 (5) ◽  
pp. 479-488 ◽  
Author(s):  
Dabin Cui ◽  
Boyang An ◽  
Paul Allen ◽  
Ruichen Wang ◽  
Ping Wang ◽  
...  
Keyword(s):  
Fourth Order ◽  
High Speed ◽  
Higher Order ◽  
Ride Quality ◽  
Sustained Use ◽  
High Speed Trains ◽  
Cut Quality ◽  
Multiple Unit ◽  
Component Failures

During both running and wheel cut operations, wheels of railway vehicles and the friction rollers that support and drive the wheelset on a typical wheel cut lathe are subject to wear and hence are likely to develop out-of-round characteristics after sustained use. The resulting out-of-round wheels can significantly affect the ride quality and can potentially increase the incidence of fatigue-related component failures due to the resulting higher intensity loading cycles. Furthermore, the corresponding out-of-round characteristics of the lathe's friction rollers will continue to degrade the subsequent cut quality of wheels. For the analysis of the out-of-round characteristics caused by an underfloor wheel lathe used for the high-speed trains in China, a mathematical model based on a typical electric multiple unit (EMU) vehicle's wheelsets and their interactions with the wheel lathe friction rollers was established. Factors influencing the cut quality of the wheels, including the number of cuts, eccentricity forms of the friction rollers and the longitudinal spacing of the two rollers, have been analysed. The results show that two cuts can effectively remove the higher order polygon on the wheel surface. The eccentricity and phase angle of the friction rollers have no influence on the cut quality of higher order polygons, whereas they are the primary cause for the fourth-order polygons. The severity of the fourth-order polygon depends on the level and the phase of the eccentricity of the friction rollers. The space of the two rollers can also significantly affect the cut quality. Obtaining the theoretical and practical value for the maintenance of polygonised wheels using the underfloor lathe is the main outcome of this study.

Compliant Variation Analysis for High-Speed Train With Consideration of Welding Distortion

2018 ◽  
Author(s):  
Tao Liu ◽  
Yongjun Li ◽  
Baowang Li ◽  
Zhimin Li ◽  
Limin Yao ◽  
...  
Keyword(s):  
High Speed ◽  
Manufacturing Industry ◽  
Structural Deformation ◽  
Angular Distortion ◽  
Welding Distortion ◽  
Variation Analysis ◽  
Analysis Model ◽  
Variation Propagation ◽  
High Speed Trains ◽  
And Performance

An important goal of the manufacturing process is to achieve high accuracy and reliability of products. For modern equipment manufacturing industries, such as high-speed trains (HST), the assembly performance is guaranteed by the product design and manufacturing technique. Since dimensional control is much related to manufacturing quality, assembly variation analysis methods play an increasingly crucial role in advanced manufacturing industry. Nevertheless, the relationship between welding distortions and tolerance design has not been considered in most existing assembly variation analysis models, which lack of quantitative analysis between precision and performance. In this study, a compliant variation analysis methodology considering both static structural deformation and welding distortion is developed and applied to predict assembly variation of the roof of HST. Firstly, welding simulation is carried out to predict welding shrinkage and angular distortion with different welding configurations. Then, welding distortion is equivalent to dimensional variation and considered in the compliant variation analysis model with offset tolerance technique. Finally, a compliant variation simulation is carried out to investigate the variation propagation influence of welding shrinkage and distortion on the final dimension of assembly. The presented methodology provides an efficient tool for variation analysis of HST, also offers a theoretical basis and experimental support for mechanical properties of compliant assembly.

Investigation of low damped carbody oscillation for Korean high-speed EMU experimental train

2021 ◽  
pp. 095440972110082
Author(s):  
Joonhyuk Park
Keyword(s):  
High Speed ◽  
Damping Ratio ◽  
Field Tests ◽  
Lateral Movement ◽  
Vehicle Model ◽  
High Speed Trains ◽  
Parametric Studies ◽  
Multiple Unit ◽  
Wheel Profile ◽  
Equivalent Conicity

This study describes the low damped carbody oscillations of the HEMU-430X, a high-speed electric-multiple-unit experimental train of Korea. The HEMU-430X had already undergone a kind of hunting problem in the test period, but it was effectively suppressed through several measures and the test was finished successfully. However, recently, the HEMU-430X again experienced the similar but slightly different problem after its wheel profile was changed to XP55, which is widely used in high-speed trains in Korea. In this paper, the eigenbehavior and system damping ratio are analyzed using a linearized vehicle model to more systematically investigate the cause of the carbody oscillation of the HEMU-430X. The results show that the bogie lateral movement coupled with carbody upper sway has the least damping ratio in the case of the HEMU-430X and the magnitude of yaw directional constraints of the bogie plays an important role in causing the carbody oscillation. Parametric studies for suspension, equivalent conicity and creep coefficients are carried out. A solution is suggested and it is validated using field tests.

A method for assessing resilience of high-speed EMUs considering a network-based system topology and performance data

2021 ◽  
pp. 1748006X2110045
Author(s):  
Shuai Lin ◽  
Limin Jia ◽  
Hengrun Zhang ◽  
Yanhui Wang
Keyword(s):  
System Performance ◽  
High Speed ◽  
Performance Data ◽  
Mathematical Expressions ◽  
Resilience Index ◽  
And Performance ◽  
Definition Of ◽  
Chinese Standard ◽  
Multiple Units ◽  
System Topology

The high complexity of the system topology and the uncertainty of threats necessitate the consideration of the resilience of high-speed electric multiple units (EMUs). This paper first gives a definition of high-speed EMU resilience. Then, the structure of a high-speed EMU is described in the form of a network to enable the application of network science for resilience evaluation based on corresponding mathematical expressions. Afterward, a measure of system performance (MSP) is constructed that considers the influence of the high-speed EMU topology and performance data. According to the definition of resilience of a high-speed EMU, a system resilience measurement (SRM) is proposed that comprehensively considers the degree and time of the change in system performance. The validity of our method is then illustrated by applying it to the system topology and performance data associated with the Chinese standard electric multiple units (CEMUs) that serve on high-speed railways in China. Experiments are reported to illustrate the concept of resilience and the procedure for its measurement and to present comparisons with an existing resilience index. Our results indicate that the SRM proposed here can capture the sensitivity of the response of high-speed EMUs to the disturbances, thereby supporting the optimal design and risk management.

Study on Dynamic Marshalling and Coupled Control of China’s High-Speed Electric Multiple Unit

2014 ◽  
Vol 1046 ◽  
pp. 315-322 ◽  
Author(s):  
Yang Liu ◽  
Chang Xian Li ◽  
Tong Zhang ◽  
Yan Nan Sun
Keyword(s):  
Communication Technology ◽  
High Speed ◽  
Development Trend ◽  
Network Communication ◽  
Market Demand ◽  
Transport Capacity ◽  
High Speed Railway ◽  
Multiple Unit ◽  
Multiple Units ◽  
Operation Cost

In order to reduce operation cost and improve transport capacity of China high-speed railway, train dynamic marshalling often need to be implemented between different kinds of China’s high-speed Electric Multiple Units (EMUs). Based on the operation situation of China high-speed railway, this paper analyzes the market demand and feasibility of dynamic marshalling between different kinds of EMUs, and describes the principle how to realize it by using TCN and UIC network communication technology. Some key problems which need to be solved in the process of realizing coupled control between different kinds of EMUs are pointed out, and corresponding suggestions how to solve these problems are proposed as well. Moreover, according to the technical development trend of the EMU, this paper predicts the possibility of using network communication technology based on real-time Ethernet to realize EMU marshalling and coupled control.

scholarly journals HIGH SPEED RAILWAY LINES – FUTURE PART OF CZECH RAILWAY NETWORK?

2017 ◽  
Vol 11 ◽  
pp. 74
Author(s):  
Lukáš Týfa ◽  
David Vodák
Keyword(s):  
High Speed ◽  
Railway Network ◽  
High Speed Rail ◽  
High Speed Railway ◽  
Railway Line ◽  
High Speed Trains ◽  
The One ◽  
Infrastructure Maintenance ◽  
The Relationship ◽  
Multiple Units

The paper first describes high speed rail generally and explains the relationship between high speed and conventional railway networks (according to the vehicle types in operation on the network). The core of the paper is comprised of the methodology for choosing the best route for a railway line and its application to the high speed railway connection Praha – Brno. The Algorithm used assumes the existence of more route proposals, which could be different in terms of the operational conception, line routing or types of vehicles used. The optimal variant is the one with the lowest daily cost, which includes infrastructure and vehicle costs; investment and operational costs. The results from applying this model confirmed the assumption, that a dedicated high speed railway line, only for high speed trains, has the same or lower investment costs than a line for both high speed and conventional trains. Furthermore, a dedicated high line also has a lower cost for infrastructure maintenance but a higher cost for buying high speed multiple units.

Multi-physics analysis of a novel circular pantograph catenary system for high-speed trains

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Song Xiao ◽  
Yuanpei Luo ◽  
Jingchi Wu ◽  
Can Zhang ◽  
Yang Rao ◽  
...  
Keyword(s):  
High Speed ◽  
Electrochemical Corrosion ◽  
Superior Performance ◽  
Technical Solution ◽  
Content Type ◽  
Continuous Contact ◽  
High Speed Trains ◽  
Catenary System ◽  
And Performance ◽  
Physics Model

Purpose In high-speed trains, the energy is supplied from a high voltage catenary to the vehicle via a pantograph catenary system (PCS). Carbon pantograph strips must maintain continuous contact with the wire to ensure safety and reliability. The contact is often confined to a particular spot, resulting in excessive wear due to mechanical and thermal damage, exacerbated by the presence of an electric arc and associated electrochemical corrosion. The effectiveness and reliability of the PCS impacts on the performance and safety of HSTs, especially under high-speed conditions. To alleviate some of these adverse effects, this paper aims to propose a configuration where a circular PCS replaces the currently used pantograph strips. Design/methodology/approach Two dynamic multi-physics models of a traditional PCS with a carbon strip and a novel PCS with a circular pantograph strip catenary system are established, and the electrical and mechanical characteristics of these two systems are compared. Moreover, a PCS experimental platform is designed to verify the validity and accuracy of the multi-physics model. Findings A novel circular pantograph system is proposed in this paper to alleviate some of the shortcomings of the traditional PCS. Comparing with a traditional PCS, the circular PCS exhibits superior performance in both electromagnetic and thermal aspects. Originality/value The paper offers a new technical solution to the PCS and develops a dedicated multi-physics model for analysis and performance prediction with the aim to improve the performance of the PCS. The new system offers numerous benefits, such as less friction heat, better heat dispersion and improved catenary-tracking performance.

An Actively Controlled Hydraulic Carbody Centering System for the Lateral Suspensions of High Speed Trains

2009 ◽  
Author(s):  
Giovanni Jacazio ◽  
Alberto Magnani ◽  
Laura Gastaldi ◽  
Gualtiero Balossini
Keyword(s):  
High Speed ◽  
Fast Response ◽  
Control Law ◽  
System Control ◽  
Test Results ◽  
Damped Oscillations ◽  
Innovative Solution ◽  
High Speed Trains ◽  
And Performance ◽  
Actuation Systems

High speed trains normally use pneumatic actuation systems to recenter the carbody with respect to the bogie when the train negotiates a curve. Pneumatic systems are used because of their compliance, necessary to ensure dynamic isolation between carbody and bogie, but have the drawbacks of large dimensions and slow response, often accompanied by a few damped oscillations. An innovative solution was developed using hydraulic actuators with an adaptive control law providing the actuators with artificial compliance, hence making them suitable for this application. A carbody centering system is thus obtained presenting fast response, small volume and the necessary compliance. The optimal control law for this system was defined, the system dynamic characteristics were analyzed and a technological demonstrator was built to assess the system merits. The paper presents the theoretical grounds for the system control, its implementation and performance, and the most significant test results obtained with the technological demonstrator.

Sign in / Sign up

Export Citation Format

Share Document