Research On Optimization Method Of Train Operation Adjustment Considering In Freight Transport Timeliness

Emergencies may lead that the train can’t run by train diagram,and train delay not only affect transport efficiency but also reduce the level of safety.In order to restore its running state by train diagram,the train operation adjustment is necessary.Under the background of railway freight transport system reform,the freight transport timeliness should be fully considered when the train diagram is adjusted.Therefore,improving owner’s satisfaction for freight transport timeliness is treated as the adjustment target.Meanwhile,the microevolution algorithm is used for the train operation adjustment.In this way,freight transport timeliness reducing can be avoided in train operation adjustment.Firstly,the train operattion adjustment is summarized.Based on the background of railway freight transport system reform,the classification of railway freight transport products is analyzed.The freight transport timeliness is analyzed by freight transit period and residence time in railway station.On one hand,the concept and calculation method of freight transit period are introduced,and freight transit period has important significance for that railway transport adapts to social demand and enlarges market share.On the other hand,the measures of compressing the residence time in railway station are analyzed and discussed,and "the compression ratio of residence time in railway station" is put forward to reflect the station operation timeliness in train operation adjustment.Secondly,owner’s satisfaction for freight transport timeliness is analyzed,and the satisfaction is treated as the objective function of train operation adjustment model.Considering various factors such as trains,goods,stations and line,the evaluation index system of freight train comprehensive importance is established.The evaluation index system is evaluated based on structure entropy weight method,and the result is treated as the weight of freight train in the objective function.Thirdly,the microevolution algorithm(MEA)which is suitable for train operation adjustment is put forward.Gene structure microevolution is the core content of MEA.The dominance gene structure can be preserved in the evolution procedure,in order to more quickly and efficiently solve the problem.In addition,the primal-dual mapping operator is used for MEA in order to adapt to the change of environment information.In the process of train operation adjustment,the depart order is determined firstly with microevolution algorithm,then the specific arrival and depart time of each train are determined under the constraint conditions.Finally,a section of Lanzhou-Xinjiang Railway is selected as the case,and the section is upward direction and includes 10 stations.MEA and genetic algorithm are respectively used for train operation adjustment model.The comparison of results shows that MEA behaves much more efficiently than genetic algorithm,because the dominance gene structure is destroyed in crossover and mutation operations of genetic algorithm.