Optimization Research On Arrival And Departure Track Utilization For Railway Marshalling Station Based On Petri Net

The utilization of arrival and departure track is the key section of railway marshalling stations’ transportation and production.It could arrange the station track rationally for the train based on the existing station equipment resources to ensure the punctual and safe reception and departure of the train. Besides, as an important part of station stage plan, the application plan of arrival-and-departure track has a close relationship with the train shunting plan and the port plan. Therefore, the optimization of arrival and departure track utilization could improve the production efficiency of the overall railway marshalling station significantly.This thesis first introduces the relevant materials including arrival and departure track operation of railway marshalling station. Further, the crossing and organization of the train operation route at the throat area is analyzed. On that basis, we compute the occupied time of the route and the track, and summarize the major factors that can affect the arrival and departure track application of the railway marshalling station.Through analyzing the characteristics of arrival and departure track utilization, many properties of DEDS can be found. Thus, this thesis proposes the ideas that model of the arrival and departure track utilization at the railway marshalling station is established by Petri net and describes the advantages of Petri network solving the problem. Then relevant conceptions of the arrival and departure track utilization are illustrated through the element of Petri net. Hence, this thesis constructs fundamental ordinal, parallel and eclectic models based on Petri net. Besides, considering the increase of scenario scale, where ordinary Petri network may incur some troubles during the modeling process such as the explosion of the state space.So by introducing the concept of colored timed Petri net, we build colored timed Petri net model respectively based on tracks allocation and routes selection.Petri net can provide graphical modeling approach, but also have the powerful ability of mathematical analysis. This thesis proposes novel operation algorithms of colored time Petri network according to the study of the existing Petri network state function, and effectively solves the problem of trains’ arrival order by introducing the concept of the token timestamp.Then, on the basis of L1 algorithm, we investigate the scheduling decision of the model deeply and design optimal heuristic dispatching algorithms in terms of minimum cross coupling and equipment balanced use, respectively.Besides, taking into account the fact that the arrival and departure track utilization could be affected by some stochastic factors during daily transportation and production such as trains delay, it is necessary to analyze the robustness of the proposed scheme. We build the time Petri network model of the known scheme and simulate the follow-up late arrivalsoccurred by the scheme to evaluate its robustness through adding late arrival disturbance.Finally, numerical results of Lanzhou North Station demonstrate the rationality and validity of proposed model, scheduling algorithms and robustness analysis, and provide theory basis for decision-making to station staffs.