Optimization on Train Operation Adjustment on Single-track Railway from Discrete Perspective

A simulation model of discrete system is constructed from a perspective of system simulation to solve theproblem of adjusting multi-class train operation on a single-track railway , considering key constraints such as the typeof technical operation and the number of arrivals and departure tracks at each station. Based on the existing train advance strategy, an event transfer function is designed to avoid the repeated execution of the adjustment strategy duringinterval operation and the minimum stopping time of the train at the station. In this way,the system timeliness isstrengthened during the simulation of adjusting multi-class train operation.Considering the difficulties caused bymulti-class trains for conflict reliefs,a finite random strategy adjustment for same-class trains and a layered randomstrategy adjustment for multi-class trains are sequentially designed using the advantage of hierarchical decision making in predicting crossing stations and overtaking stations. It can improve the global searching ability of the discretesimulation system during adjusting train operation.Finally, the effectiveness and rationality of the simulation model ofthe discrete system,as well as the strategy adjustment,are verified through an example analysis. The results areshown as follows: ① The strategy adjustment designed in the work can improve the quality of the solution by about 5.77%.② The event transition function in the strategy adjustment can improve the timeliness of the system simulationby about 34.47%.③ Although the hierarchical strategy can ensure the timeliness of high-class trains,it needs to sacrifice the timeliness of low-class trains,losing the system's timeliness by about 45.3%