The Study On Train Operation Simulation, Real-time Scheduling Model And Algorithm

ABSTRACT:Under the environment of mixed operation with different types of trains on the railway network, due to the disturbances of unexpected events, the conflict will happen to the train operation at the nodes in the network. Conflict resolution requires decision-making support system to automatically engender advanced scheduling strategies so as to improve the efficiency of train operation. The status quo and methods of train operation optimal scheduling are analyzed, and further the real-time predictive scheduling (RTPS) combined with the alternative graph model with speed adjustment is proposed based on the mechanism of model predictive control. Some research conclusions are drawn through train operation simulation.The main research contents and conclusions are as follows:1. Based on the alternative graph model in the job shop scheduling theory, train operation scheduling problem can be formulated by a series of time constrains of occupied resources. Some formulation methods are introduced about the characteristics of track traffic flow operation in the alternative graph. Alternative graph can model the real-time characteristics of train operation more effectively by adding the update of trains'speeds. And two simplifying rules are adopted in the pre-processing stage of the alternative graph model, which can greatly reduce the computation burden.2. Current algorithms for resolving train scheduling problem are analyzed. The real-time predictive scheduling (RTPS) combined with the alternative graph model is proposed based on the mechanism of model predictive control, i.e. predictive model, rolling optimization and real-time feedback adjustment. The proposed algorithm can resolve conflicts based on predicted information of train operation. This paper presents the detailed RTPS algorithm and concrete realization procedures.3. The simulation platform of train operation is implemented in C++language. What's more, the detailed design ideas and the programming procedure are presented. Its primary functions include train operation according to the initial timetable, conflict detection and algorithm implementation. A simulation with respect to a large railway network has been carried out, and four scheduling algorithms are implemented under the case of preset disturbances. The simulation results demonstrate the advantage of RTPS over the heuristic scheduling strategies such as FCFS (first come first served), FLFS (first leave first served), and AMCC (avoid maximum current Cmax) in the current literature. The proposed scheduling algorithm can provide more effective decision strategies for the dispatcher.This paper has basically accomplished the research on the real-time scheduling based on the simulation prediction of train operation by adopting the alternative graph, and combines the simulation of train operation with the scheduling-based performance optimization. The results are anticipated, and finally the future work is outlined.