Optimization Of Route Assignment Problem At High-speed Railway Station

In the condition of large-scale construction of high-speed railway stations and growing number of trains received and dispatched at station in China,formulating reasonable and feasible route allocation scheme is of great significance for improving the efficiency of station operation and the stability of station operation plan.The operation process corresponds to the train route one by one,without consideration of the route release by section,the throat area and arrival-departure track are occupied at the same time of preparing train route until the end of the station operation process.On the basis of analyzing the application elements of throat area and arrival-departure track,defining the part of the throat area occupied by the train route as throat area channel,there may be mutual interference between different throat area channels,one throat area channel may be connected to many arrival-departure tracks,and there may be multiple throat area channels can be selected when trains arrival or departure.Considering the restriction between throat area and arrival-departure track in high-speed railway station,the connection between the operation process and equipment,and the cohesive relation between different operation process which belong to the same train,in combination with the method of turnout grouping,considering the minimum disequilibrium use of arrival-departure track and that of turnout group as the optimization objectives,the optimization model M1 of train route allocation scheme was established,which is based on the integrated application of throat area and arrival-departure track.With the train route allocation scheme presumed by model M1 as established scheme and put it into effect.In this process,when some trains are late and cause cross interference of subsequent train routes,On the basis of model M1,considering the minimum number of trains that not use established track and the minimum average delay time of operation process as the optimization objectives,the adjustment model M2 of train route allocation scheme for the following trains was established.Model M1 and M2 are large-scale linear programming models,both of them were solved by the method of MATLAB loading YALMIP and then calling CPLEX software.Finally,in the peak period of 18:00 to 21:00,the Beijing-Shanghai field of Nanjingnan Railway Station receive and dispatch 57 trains,with the 57 trains as research object,the rationality of model and the feasibility of algorithm were verified.The results show that model M1 ensure that trains pass in and out station according to the train diagram,the optimization scheme compare with the original scheme,the disequilibrium index of arrival-departure track was reduced from 15.08 to 2.28,the disequilibrium index of turnout group was reduced from 19.5 to 17.11,the effect of optimization was obvious.When G1927 and G9410 are both 5 minutes late and cause cross interference of subsequent train routes,model M2 effectively ensures the train route unimpeded.If the model M2 focus on the minimum number of trains that not use established track,the adjustment scheme I compare with the optimization scheme,the equilibrium use of arrival-departure track and that of turnout group are both unchanged,all trains access to established track,5 trains are delayed,and the average delay time of the following train is 0.41 min.If the model M2 focus on the minimum average delay time of operation process,the adjustment scheme II compare with the optimization scheme,the unequilibrium index of arrival-departure track increased from 2.28 to 6.5,the equilibrium use of arrival-departure track become poor,the equilibrium use of turnout group is unchanged,one train does` t use established track,3 trains are delayed,and the average delay time of the following train is 0.21 min.