scholarly journals Evaluating Line Capacity with an Analytical UIC Code 406 Compression Method and Blocking Time Stairway

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1853
Author(s):  
Ruxin Wang ◽  
Lei Nie ◽  
Yuyan Tan
Keyword(s):  
High Speed ◽  
Operating Conditions ◽  
Compression Method ◽  
High Speed Railway ◽  
Traffic Demand ◽  
Scheduling Model ◽  
Actual Operating ◽  
Significant Research ◽  
Positive Capacity

Railways around the world are experiencing growth in traffic flow, but the problem concerning how to optimize the utilization of capacity is still demands significant research. To accommodate the increasing traffic demand, the high-speed railway operator in China is interested in understanding the potential benefit of adopting reasonable headway to balance the safety and efficiency of train operations. In this study, a compress timetable scheduling model based on the UIC Code 406 method is presented to evaluate the line capacity. In this model, train headway is not pre-fixed as in the existing research, but considers the actual operating conditions and is calculated using actual running data. The results of the case study show that refined headway calculations generally have positive capacity effects.

scholarly journals Using Improved Ant Colony Algorithm to Investigate EMU Circulation Scheduling Problem

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Yu Zhou ◽  
Leishan Zhou ◽  
Yun Wang
Keyword(s):  
High Speed ◽  
Ant Colony Algorithm ◽  
Travel Demand ◽  
Maintenance Cost ◽  
High Speed Railway ◽  
Scheduling Scheme ◽  
Scheduling Model ◽  
Traditional Approaches

High-speed railway is one of the most important ways to solve the long-standing travel difficulty problem in China. However, due to the high acquisition and maintenance cost, it is impossible for decision-making departments to purchase enough EMUs to satisfy the explosive travel demand. Therefore, there is an urgent need to study how to utilize EMU more efficiently and reduce costs in the case of completing a given task in train diagram. In this paper, an EMU circulation scheduling model is built based on train diagram constraints, maintenance constraints, and so forth; in the model solving process, an improved ACA algorithm has been designed. A case study is conducted to verify the feasibility of the model. Moreover, contrast tests have been carried out to compare the efficiency between the improved ACA and the traditional approaches. The results reveal that improved ACA method can solve the model with less time and the quality of each representative index is much better, which means that efficiency of the improved ACA method is higher and better scheduling scheme can be obtained.

Notch-based speed trajectory optimisation for high-speed railway automatic train operation

2021 ◽  
pp. 095440972110421
Author(s):  
Minling Feng ◽  
Chaoxian Wu ◽  
Shaofeng Lu ◽  
Yihui Wang
Keyword(s):  
High Speed ◽  
Applied Force ◽  
Mixed Integer ◽  
High Speed Railway ◽  
Train Operation ◽  
Train Speed ◽  
Automatic Train Operation ◽  
The Impact ◽  
Trajectory Optimisation

Automatic train operation (ATO) systems are fast becoming one of the key components of the intelligent high-speed railway (HSR). Designing an effective optimal speed trajectory for ATO is critical to guide the high-speed train (HST) to operate with high service quality in a more energy-efficient way. In many advanced HSR systems, the traction/braking systems would provide multiple notches to satisfy the traction/braking demands. This paper modelled the applied force as a controlled variable based on the selection of notch to realise a notch-based train speed trajectory optimisation model to be solved by mixed integer linear programming (MILP). A notch selection model with flexible vertical relaxation was proposed to allow the traction/braking efforts to change dynamically along with the selected notch by introducing a series of binary variables. Two case studies were proposed in this paper where Case study 1 was conducted to investigate the impact of the dynamic notch selection on train operations, and the optimal result indicates that the applied force can be flexibly adjusted corresponding to different notches following a similar operation sequence determined by optimal train control theory. Moreover, in addition to the maximum traction/braking notches and coasting, medium notches with appropriate vertical relaxation would be applied in accordance with the specific traction/braking demands to make the model feasible. In Case study 2, a comprehensive numerical example with the parameters of CRH380AL HST demonstrates the robustness of the model to deal with the varying speed limit and gradient in a real-world scenario. The notch-based model is able to obtain a more realistic optimal strategy containing dynamic notch selection and speed trajectory with an increase (1.622%) in energy consumption by comparing the results of the proposed model and the non-notch model.

scholarly journals A Study on the Practical Carrying Capacity of Large High-Speed Railway Stations considering Train Set Utilization

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Bin Guo ◽  
Leishan Zhou ◽  
Yixiang Yue ◽  
Jinjin Tang
Keyword(s):  
Carrying Capacity ◽  
High Speed ◽  
Programming Model ◽  
High Speed Railway ◽  
Railway Stations ◽  
China Studies ◽  
Important Nodes ◽  
Entire Network

Methods for solving the carrying capacity problem for High-Speed Railways (HSRs) have received increasing attention in the literature in the last few years. As important nodes in the High-Speed Railway (HSR) network, large stations are usually the carrying capacity bottlenecks of the entire network due to the presence of multiple connections in different directions and the complexity of train operations at these stations. This paper focuses on solving the station carrying capacity problem and considers train set utilization constraints, which are important influencing factors that have rarely been studied by previous researchers. An integer linear programming model is built, and the CPLEX v12.2 software is used to solve the model. The proposed approach is tested on a real-world case study of the Beijing South Railway Station (BS), which is one of the busiest and most complex stations in China. Studies of the impacts of different train set utilization constraints on the practical station carrying capacity are carried out, and some suggestions are then presented for enhancing the practical carrying capacity. Contrast tests indicate that both the efficiency of the solving process and the quality of the solution show huge breakthroughs compared with the heuristic approach.

Heterogeneous impact of high speed railway on income distribution: A case study in China

2021 ◽  
pp. 101128
Author(s):  
Mengjie Jin ◽  
Wenming Shi ◽  
Yu Liu ◽  
Xiaoling Xu ◽  
Kevin X. Li
Keyword(s):  
Income Distribution ◽  
High Speed ◽  
High Speed Railway

Application of Particle Swarm Algorithm in Train-Set Circulation Problem of China

2012 ◽  
Vol 253-255 ◽  
pp. 1235-1240
Author(s):  
Hua Li ◽  
Bao Ming Han ◽  
Fang Lu ◽  
Xiao Juan Li
Keyword(s):  
High Speed ◽  
Particle Swarm Optimization Algorithm ◽  
Programming Model ◽  
Real Life ◽  
Particle Swarm ◽  
Particle Swarm Algorithm ◽  
High Speed Railway ◽  
Railway Line ◽  
Circulation Problem

Train-set circulation problem is an important issue in operations of high-speed passenger trains in the world. On the basis of characteristics of the train-set circulation problem in China, an integer programming model is presented without considering distinct train-set types. With redefinitions of some basic mathematical objects and operations, an improved particle swarm optimization algorithm is proposed to solve the model. The algorithm is applied in a real-life case study based on the timetable of the Wuhan-Guangzhou High-speed Railway Line. The results show that the proposed algorithm is effective to find the optimized train-set circulation plan.

The Non-Uniform Preloading Effect on Stiffness Behaviour of Angular Contact Ball Bearings

2012 ◽  
Author(s):  
Wenwu Wu ◽  
Jun Hong ◽  
Xiaohu Li ◽  
Yang Li ◽  
Baotong Li
Keyword(s):  
High Speed ◽  
Ball Bearing ◽  
Operating Conditions ◽  
Structural Performance ◽  
Angular Contact Ball Bearing ◽  
Actual Operating ◽  
Bearing Life ◽  
Bearing Stiffness ◽  
Increasing Demand ◽  
Bearing System

With the increasing demand of higher operating speed for bearing system, more challenges have been exposed on the maintaining of the bearing performance. Preloading is an effective method to handle these challenges. Traditionally, the preloading of bearing system has been applied by uniform approaches such as rigid preload and constant preload. However, this treatment may hardly deal with the optimization of preloading problem due to the non-uniformity of the bearing stiffness becomes more apparent under high-speed operating conditions. A novel and practical approach is therefore presented in this paper to incorporate the non-uniformity effect to improve the structural performance of bearing under actual operating conditions. Firstly, the critical relationship between the stiffness behaviour and the non-uniform preload is evaluated for bearing system. The stiffness problem of angular contact ball bearing system is then formulated analytically by Jones’ model. With this approach, boundary conditions are achieved to solve the local contact deformation and predict the bearing life under non-uniform preload. Finally, both the uniform preload and the non-uniform preload cases for bearing system are simulated under various operating conditions. Comparing with traditional methods, the proposed method can provide a better solution in both stiffness and life that will enable a designer to obtain a deep insight on the optimization of bearing system.

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