Wei ShangGuan

Multiobjective Optimization for Train Speed Trajectory in CTCS High-Speed Railway With Hybrid Evolutionary Algorithm

A speed trajectory profile indicating the authorized train speed at each position can be used to guide the driver or the automatic train operation (ATO) system to operate the train more efficiently, which is the most important part of the Chinese Train Control System (CTCS) and will decide the safety and efficiency of train operation. The efforts produced by the train to follow the speed trajectory will directly affect the evaluation of train operation. This paper studies the optimization approach for the speed trajectory of high-speed train in a single section. First, we take the energy consumption as the measure of satisfaction of the railway company, and the trip time is being regarded as the passenger satisfaction criterion; then, we present optimal speed trajectory searching strategies under different track characteristics by dividing the section into some subsections according to different speed limitations. After that, we develop a multiobjective optimization model for the speed trajectory, which is subject to the constraints such as safety requirement, track profiles, passenger comfort, and the dynamic performance. For obtaining the Pareto frontier of train speed trajectory, which has equal satisfaction degree on all the objects, a hybrid evolutionary algorithm is designed and applied to solve the model based on the differential evolution and simulating annealing algorithms. By showing some numerical results of simulations, the efficiency of the proposed model and solution methodology is illustrated.

A GPS/compass based train integrated positioning method for high-speed railways

Accurate and real-time positioning is an important part of train control, which is crucial for safety assurance of high speed railway in China. For GPS based train positioning scheme, the signal unavailability and signal interference could not be completely solved with current configuration mode. In this paper, from the safety requirements of train positioning in high-speed railways, based on the consideration of signal availability and fault-tolerant performance, an integrated train positioning system is formed by integration of GPS and Compass. The structure and function of the integrated system are given, and the nonlinear filter solution for information fusion is presented, which is compared to traditional Kalman filter based strategies. An HTL-based integrity monitoring method is presented to enhance fault tolerant ability. Results from experiments and simulations demonstrate the integrated positioning method could meet the precision requirement with effective integrity characteristics, and keep its potential for efficiency and safety in various environments.

Research on deeply integrated GPS/INS for autonomous train positioning

With the speed-up of trains, the trains positioning environment becomes increasingly complex which requires the trains positioning system have enough anti-interference capability to ensure the precision and reliability of trains positioning. GNSS/INS deeply integrated positioning system could improve the anti-interference ability of the positioning system, achieving real-time positioning with much higher precision and reliability. In this paper, a deeply integrated GNSS/INS strategy for train locating based on vector tracking loop was proposed, and the mathematical model for GNSS/INS integrated system was established.

Research of train control system special database and position matching algorithm

The research on low-cost train control system is one of the most important part in train traffic field, using GPS data could realized real-time, safe and reliable train positioning. The train control system special database was studied systematically, the data model and mathematical topology model of data format was established, and the whole seven steps of special database creation were designed. Then according to feature of railway, using adaptive position matching algorithm in rail track positioning, the track was divided into beeline and circle curve, the algorithm base on movable distance frame could realized accurate, real-time and quick positioning. Finally, experiment was done in Sanjiadian marshalling station; the experiment result proves that the special database is valuable and effective for train positioning.

Moving Horizon Optimization of Dynamic Trajectory Planning for High-Speed Train Operation

Trajectory planning plays a crucial role in train operation by providing with the authorized speed at each position. The traditional static train trajectory planning methods are always designed offline according to a preplanned timetable, and they ignored the uncertainties of parameters, resulted by line condition, resistance coefficient, and delay. These uncertain disturbances have not been considered adequately in previous studies. This paper deals with the dynamic optimal train trajectory planning problem with uncertainties. First, in order to identify uncertain resistance coefficients and calculate the dynamic limited speed, we present the optimization framework using onboard equipment such as a global navigation satellite system (GNSS) terminal, a power supply system, and a communication device to sample the real-time traffic information. Then, by taking the energy consumption and punctuality as objectives, we propose a moving horizon train trajectory planning optimization model with an adaptive weight allocation mechanism based on trip time error. The innovation of this paper lies not only in the establishment of a novel dynamic optimization model for train trajectory planning but also the strategy that combines real-time traffic information with the trajectory planning procedure. By contrast with most existing solutions, the proposed approach fully takes advantage of the real-time information and thus avoids the difficulties for modeling the uncertain coefficients for train trajectory planning. The efficiency of the proposed approach is illustrated by showing some numerical results of simulations with the infrastructure data from Beijing-Shanghai High-speed Railway of China.

Research on simulation technology of HLA-based cooperative vehicle-infrastructure system

Research of cooperative vehicle-infrastructure system (CVIS) is of great significance for the transportation system development. Firstly, introduction of multi-resolution in this paper helps to establish High Level Architecture ??HLA??-based CVIS in three dimensions. Secondly, DEVS descriptions for CVIS compatible to HLA as well as multi-resolution modeling (MRM) and simulation theory are proposed in accordance with CIVS specification. Thirdly, simulation architecture of real-time distributed, interactive extensible and invertible CVIS is established. Finally, adjustment and test on federal members in CVIS are conducted and basic functions of the platform are implemented. The results indicate that the simulation system could provide the CVIS module with practical module design and supporting environment to verify functionality of different modules.

Adaptive Fuzzy Planning of Optimal Speed Profiles for High-Speed Train Operation on the Basis of a Pareto Set

Today, one of the main concerns for railways administrations and operators is reducing energy consumption. Ecodriving design is one of the main approaches to reducing energy consumption with low levels of investment. In this paper, a Pareto set–based adaptive fuzzy approach to trajectory planning is proposed to generate energy-efficient speed profiles for high-speed train operation. First, the Pareto set for high-speed train operation is constructed by using a hybrid evolutionary algorithm based on differential evolution and simulated annealing. Second, by considering that the operational delays are variable because of the uncertainties of line conditions in practice, a system to control adaptive fuzzy predictions is proposed to regulate the coasting point dynamically so as to meet the requirements of punctuality and energy savings. The proposed approach decreases the energy consumption of high-speed trains mainly by changing the coasting point, a technique that make implementation easy and guarantees passenger comfort compared with frequent changes under different operating conditions. Finally, the proposed approach is analyzed by using real operational data from the Wuhan–Guangzhou high-speed railway line in China to assess energy savings and punctuality. The results of simulation illustrate the efficiency of the proposed approach.

Unsignalized Cooperative Optimization Control Method based on Vehicle Speed Guidance and Information Interaction

This paper introduces a new approach for optimization controlling the traffic at an unsignalized cooperative intersection under the Cooperative Vehicle Infrastructure System (CVIS) environment. An unsignalized cooperative optimization control method is proposed for effective intersection operations and management based on vehicle speed guidance and information interaction. For the features of information interaction in CVIS, the proposed method that does not require a traffic signal controller at the intersection; instead vehicle speed guidance and “right of way” information optimized by the method will be show on the DMI of On-Board Unit (OBU). Paper developed an unsignalized cooperative optimization control simulation platform based on the Q-Paramics. Experimental results show that compared with traditional actuated control method, the proposed method can effectively reduce the intersection average delay, number of stops and length of queue.

Research of information interaction simulation method in Cooperative Vehicle Infrastructure System

The efficiency and performance of simulation method for information interaction process of Vehicular Ad-hoc Network (VANET) plays a crucial role in future Cooperative Vehicle Infrastructure System (CVIS). This paper puts forward a simulation method for information interaction process in CVIS based on the High Level Architecture (HLA) platform which consists of traffic simulator based on Paramics, network simulator based on OPNET and communication evaluation system in which evaluation indexes are integrated into the evaluation architecture through link-relative method. The simulation components act in close coordination with proposed time synchronization mechanism adaptively with feedback of their time differences. The test traffic scenario was built for the simulation method. The outstanding simulation results show that the time synchronization mechanism can shorten the time difference between Paramics and OPNET with proper step size, and the communication evaluation method we proposed in simulation platform can reflect the variation tendency of communication performance of VANET simulation system.

Research on car following model based on cooperative vehicle infrastructure system

This paper selects the car following model (CFM) in Cooperative Vehicle Infrastructure System (CVIS) to study. Through the study of the traditional car following model and the problem that in car following model in Paramics the safe distance value is not accurate, we design of a new minimum safe distance car following model based on Paramics car following model and the data exchange in CVIS. And we design the CVIS traffic simulation platform and compare it with the traditional safe distance of the car following model. From the simulation data, we can see that the minimum safety distance car following model based on CVIS is more efficiency.