Research On Robust Optimization Of Railway Train Stock Assignment

Railway train stock is one of the conveyance, and the important resource in the railway transportation organization. A reasonable railway train stock assignment can help saving operation cost and improve the utilization of passenger train and make the revenue maximization. At the present, train stock belong to fixed railway department and they are used on fixed lines. With the continuous increase of the number of passenger traffic, the railway passenger transport capacity is insufficient. Especially on holidays and other passenger peak hours, railway passenger transport capacity are lack. Railway company uses to take temporary additional passenger trains or Passenger Train Set Assignment Mode in order to ease transport capacity shortage. So, research on this issue is very urgent and needs.In order to analyze the situation of passenger trains, by statistic on indicators that staying time at station, train stock amount belonging to different staying period, reasons for long staying time at stations have been studied. The statistic is from 24 stations in Beijing area,Zhengzhou area, Xian area, Shanghai area and Lanzhou area, and rational train stock assignment mode has been established for decreasing staying time. Optimization model is built to reduce vehicle dwell time at stations.According to analysis of current train sets assignment, on the basis of research on uncertain railroad region, main factors which impact on train sets assignment have been studied on. At first, suppose that the passenger train is no delay, and reference the constraint conditions and objective functions in the study, then assignment optimization of railway train stock based in train string is built. Then, taking into account passenger train arrival and departure times are random uncertain. An optimization model for operations assignment of railway passenger train stock has been built to minimum unnecessary staying time at station of originating departure and terminal train stock as the objective function, and the overall consideration constraints, such as the connecting time and staying time of passenger train stock at attached station and switchback station,and the limiting requirements for train string length. At last, in order to optimize passenger train anti-jamming capability when train stock assignment, an assignment optimization of railway train stock based in the robust.A case study has been carried out taking 4 stations as an example in order to verify the validity of this model and its algorithms. The results show that the scheme which is obtained from above mentioned model and its algorithms can reduce required number of the passenger train stock and the staying time of passenger train stock at attached station and switchback station, and utilization of passenger train stock was improved. The practical problems needed to be further solved in the condition of operations assignment of train stock are analyzed, such as the effecting of delayed passenger train on the connecting of passenger train stock, and thepassenger crew how to reasonably assign.