Investigation into the braking performance of high-speed trains in the complex braking environment of the Sichuan-Tibet Railway

2021 ◽  
pp. 095440972110418
Author(s):  
Wentao Zhao ◽  
Jianming Ding ◽  
Qingsong Zhang ◽  
Weiwei Liu
Keyword(s):  
Parallel Computation ◽  
Dynamic Model ◽  
Control Strategy ◽  
High Speed ◽  
Spatial Dynamics ◽  
Dynamics Model ◽  
Braking Performance ◽  
High Speed Trains ◽  
Braking Control ◽  
Different Altitudes

The Sichuan-Tibet Railway is an east-west rapid plateau railway under construction from Chengdu to Lhasa. One of its most remarkable features is the high altitude and notable altitude fluctuations. High altitudes will result in low atmospheric pressures and temperatures. The freezing caused by low temperatures will lead to low wheel-rail adhesions. Altitude fluctuations will generate complex spatial railway tracks. To investigate the braking performance of a train in such a complex braking environment, a train spatial dynamics model, a model of a direct pneumatic brake system and a model of a braking control strategy are constructed. A comprehensive analysis model for investigating the braking performance of high-speed trains in a complex braking environment is proposed based on the constructed train spatial dynamics model, direct pneumatic brake system model and braking control strategy model. A simulation computation platform for train braking performance analysis on the Sichuan-Tibet Railway is established based on SIMPACK, AMESim, Simulink and their interfaces. The braking performance under the different altitudes, different spatial railway tracks and low adhesions are analysed in detail and summarized. Computation time are compared in different altitudes and track conditions. Computational efficiencies of the dynamic model with multi-thread parallel computation are discussed. The results indicate that an increasing altitude and the alteration of railway track conditions have a remarkable influence on the braking distance, brake cylinder pressure, instantaneous deceleration, maximum wheel-load reduction rates and maximum longitudinal impact forces of high-speed trains. The track conditions in the dynamic model have a greater impact on the computation speed. Compared to single-thread parallel computation, the computational efficiency using 2-thread parallel computation can be promoted by 22.97%. These results will provide a reference for the Sichuan-Tibet Railway design and the optimization of train braking systems.

scholarly journals Prescribed Performance Active Braking Control with Reference Adaptation for High-Speed Trains

Actuators ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 313
Author(s):  
Rui Zhang ◽  
Jun Peng ◽  
Bin Chen ◽  
Kai Gao ◽  
Yingze Yang ◽  
...  
Keyword(s):  
Steady State ◽  
Feedback Linearization ◽  
High Speed ◽  
Adhesion Force ◽  
Unscented Kalman Filter ◽  
Nonlinear Function ◽  
Slip Ratio ◽  
Prescribed Performance ◽  
High Speed Trains ◽  
Braking Control

Active braking control systems are vital for the safety of high-speed trains by leading the train operation at its maximum adhesion state. The train adhesion is a nonlinear function of the slip ratio and varies with the uncertain wheel-rail contact conditions. A nonlinear active braking control with rapid and accurate tracking performance is highly required for train braking systems. This paper proposes a novel prescribed performance active braking control with reference adaptation to obtain the maximum adhesion force. The developed feedback linearization controller employs a prescribed performance function that specifies the convergence rate, steady-state error, and maximum overshoot to ensure the transient and steady-state control performance. Furthermore, in the designed control approach, a continuous-time unscented Kalman filter is introduced to estimate the uncertainty of wheel-rail adhesion. The estimation is utilized to represent uncertainty and compensate for the prescribed performance control law. Finally, based on the estimated wheel-rail adhesion, an on-line optimal slip ratio generation algorithm is proposed for the adaptation of the reference wheel slip. The stability of the system is provided, and experiment results validate the effectiveness of the proposed method.

scholarly journals Multi-Objective Optimization Study of Regenerative Braking Control Strategy for Range-Extended Electric Vehicle

2020 ◽  
Vol 10 (5) ◽  
pp. 1789 ◽  
Author(s):  
Hanwu Liu ◽  
Yulong Lei ◽  
Yao Fu ◽  
Xingzhong Li
Keyword(s):  
Control Strategy ◽  
Regenerative Braking ◽  
Multi Objective Optimization ◽  
Braking Performance ◽  
Multi Objective ◽  
Capacity Loss ◽  
Battery Capacity ◽  
Braking Control ◽  
Braking Energy Recovery ◽  
Adhesion Condition

Currently, the researches on the regenerative braking system (RBS) of the range-extended electric vehicle (R-EEV) are inadequate, especially on the comparison and analysis of the multi-objective optimization (MOO) problem. Actually, the results of the MOO problem should be mutually independent and balanced. With the aim of guaranteeing comprehensive regenerative braking performance (CRBP), a revised regenerative braking control strategy (RRBCS) is introduced, and a method of the MOO algorithm for RRBCS is proposed to balance the braking performance (BP), regenerative braking loss efficiency (RBLE), and battery capacity loss rate (BCLR). Firstly, the models of the main components related to the RBS of the R-EEV for the calculation of optimization objectives are built in MATLAB/Simulink and AVL/Cruise. The BP, RBLE, and BCLR are selected as the optimization objectives. The non-dominated sorting genetic algorithm (NSGA-II) is applied in RRBCS to solve the MOO problem, and a group of the non-inferior Pareto solution sets are obtained. The simulation results show a clear conflict that three optimization objectives cannot be optimal at the same time. Then, we evaluate the performance of the proposed method by taking the individual with the optimal CRBP as the final optimal solution. The comparation among BP, RBLE, BCLR, and CRBP before and after optimization are analyzed and discussed. The results illustrate that characteristic parameters of RRBCS is crucial to optimization objectives. After parameters optimization, regenerative braking torque works early to increase braking energy recovery on low tire-road adhesion condition, and to reduce the battery capacity loss rate at the expense of small braking energy recovery on the medium tire-road adhesion condition. In addition, the results of the sensitivity analysis show that after parameter optimization, RRBCS is proved to perform better road adaptability regarding the distribution of solutions. These results thoroughly validate the proposed approach for multi-objective optimization of RRBCS and have a strong directive to optimize the control strategy parameters of RBS.

Dynamics modeling and analysis of a four-wheel independent motor-drive virtual-track train

2020 ◽  
pp. 146441932096401
Author(s):  
Zhonghui Yin ◽  
Jiye Zhang ◽  
Haiying Lu ◽  
Weihua Zhang
Keyword(s):  
High Speed ◽  
Load Capacity ◽  
Dynamic Performance ◽  
Spatial Dynamics ◽  
Dynamic Responses ◽  
Dynamics Modeling ◽  
Dynamics Model ◽  
Coupling Effects ◽  
Dynamic Interactions ◽  
Modeling And Analysis

Due to urbanisation and the economic challenges of traffic, it is urgently necessary to develop an environmentally friendly virtual-track train with suitable speed, high load capacity and low construction cost in China. To guide the design and evaluate this train’s dynamic behaviour, a spatial-dynamics model has been developed based on the dynamics theory and tyre-road interaction. The proposed dynamics model comprises mechanical vehicle systems, traction and braking characteristics and tyre-road dynamic interactions. The coupling effects amongst those systems of virtual track train are derived theoretically for the first time. The nonlinear characteristics of the tyre are modelled by the transit tyre-magic formula with consideration of road irregularities. Based on a designed PID controller and the comprehensive dynamics model, the dynamic performance of the system can be revealed considering motion coupling effects and complicated excitations, especially under traction and braking conditions. The dynamic responses of whole virtual track train can be obtained by numerical integration under different conditions. The vibration characteristics of such train are assessed under running at a constant speed and during the traction/braking process. The results show that the vibrations of the vehicle system are significantly influenced by road irregularities, especially at high speed ranges. The motions and vibrations of different components are intensive coupled, which should not to be neglected in the dynamics assessment of the virtual track train. Besides, the dynamics model can also be applied to dynamics-related assessment (fatigue, strength and some damage conditions, et al.) and parameter optimisation of the virtual-track train.

scholarly journals Observer Based Traction/Braking Control Design for High Speed Trains Considering Adhesion Nonlinearity

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Wenchuan Cai ◽  
Wenhao Liao ◽  
Danyong Li ◽  
Yongduan Song
Keyword(s):  
High Speed ◽  
Adhesion Force ◽  
Surface Condition ◽  
Control Design ◽  
Work Force ◽  
High Speed Trains ◽  
Train Operation ◽  
Braking Control ◽  
Key Enabling Technologies ◽  
Automatic Train Operation

Train traction/braking control, one of the key enabling technologies for automatic train operation, literally takes its action through adhesion force. However, adhesion coefficient of high speed train (HST) is uncertain in general because it varies with wheel-rail surface condition and running speed; thus, it is extremely difficult to be measured, which makes traction/braking control design and implementation of HSTs greatly challenging. In this work, force observers are applied to estimate the adhesion force or/and the resistance, based on which simple traction/braking control schemes are established under the consideration of actual wheel-rail adhesion condition. It is shown that the proposed controllers have simple structure and can be easily implemented from real applications. Numerical simulation also validates the effectiveness of the proposed control scheme.

scholarly journals Improving the Stability of the Passenger Vehicle by Using an Active Stabilizer Bar Controlled by the Fuzzy Method

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Tuan Anh Nguyen
Keyword(s):  
High Speed ◽  
Control Method ◽  
Spatial Dynamics ◽  
The Body ◽  
Vertical Force ◽  
Dynamics Model ◽  
Track Dynamics ◽  
The Difference ◽  
Lift Off ◽  
The Stability

The rollover phenomenon is a particularly dangerous problem. This phenomenon occurs when the driver travels at high speed and suddenly steers. Under the influence of centrifugal force, the body vehicle will be tilted and cause the wheels to lift off the road. To solve this problem, the method of using an active stabilizer bar has been proposed. The active stabilizer bar is controlled automatically by a previously designed controller. The performance of the active stabilizer bar depends on the selected control method. Previous research often only used a half-car dynamics model combined with a linear single-track dynamics model to simulate the vehicle’s oscillation. In addition, most of the research focuses only on the use of linear control methods for the active stabilizer bar. Therefore, the performance of the stabilizer bar is not guaranteed. This paper focuses on establishing the model of spatial dynamics combined with the nonlinear double-track dynamics model that fully describes the vehicle’s oscillation most accurately. Besides, the fuzzy control method is proposed to control the operation of the hydraulic stabilizer bar. This is a completely novel model, and it is suitable for the actual traveling conditions of the vehicle. Also, simulations are done based on different scenarios. The results of the paper showed that the values of the roll angle, the difference in the vertical force at the wheels, and the displacement of the unsprung mass were significantly reduced when the vehicle used the active stabilizer bar, which is controlled by an intelligent control method. Therefore, the stability and safety of the vehicle have been guaranteed. This result will be the basis for performing other more complex research in the future.

scholarly journals Dynamic characteristics of a high-speed train gearbox in the vehicle–track coupled system excited by wheel defects

2019 ◽  
Vol 234 (10) ◽  
pp. 1210-1226 ◽  
Author(s):  
Zhiwei Wang ◽  
Paul Allen ◽  
Guiming Mei ◽  
Zhonghui Yin ◽  
Yao Cheng ◽  
...  
Keyword(s):  
High Speed ◽  
Dynamic Stress ◽  
Three Dimensional ◽  
Coupled System ◽  
Transmission System ◽  
Dynamic Responses ◽  
Connected Components ◽  
Dynamics Model ◽  
High Speed Trains ◽  
Polygonal Wear

To analyse and simulate the dynamic responses of the gearbox in a vehicle–track system, a three-dimensional vehicle–track coupled dynamics model for high-speed trains has been developed in this study with a comprehensive consideration of the transmission system. Using this dynamics model, the coupling effects between the gearbox housing and its connected components were analysed. Based on the dynamic results, the dynamic stress field of the gearbox housing can be obtained using the finite element methods. The model outputs were successfully validated through comparisons with field test data. Following model validation, the dynamic stress and its distribution throughout the gearbox housing were further investigated under different excitations, including track irregularities, wheel polygonal wear and flatness. The results demonstrate a significant increase in the stress levels of the oil level window aperture and the bottom face of the housing, which coincides with the location of cracks that are formed in the gearbox housing during frequent vehicle operation. While a specific case has been studied here, the proposed dynamics model can be applied to related dynamic assessments, such as vibration or suspension parameter analyses, as well as to stress analyses of any rail vehicle transmission system to guide the maintenance and design.

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