Research On Key Technologies Of The Planning Of Dynamic Railway Freight Transportation Organization Based On Market Orientation

In order to realize the transformation of the Chinese railways from traditional transportation enterprise to modern logistics enterprise,make railway operations in line with the daily dynamic changes of market,organize transportation in strict accordance with plans,meet the frieght transport demands such as delivery time window,and improve the pricise degree of freight transport,the Chinese railways urgently need to make a breakthrough to change the railway freight transportation from the long-establised dispatching mode to a market-oriented,dynamic planning mode.This paper focuses on the study of the market-oriented,dynamic planning railway frieght transportation mode.Since the dynamic plans of railway freight transportation organization are the core and key techinical support to realize the reform of the freight transportation mode,this paper mainly studies the formulation theories of the dynamic plans,and further studies the key technologies of the dynamic plans,namely the dynamic wagon flow calculating,freight train formation planning,freight train operating planning.The main research work are:(1)This paper studies the market-oriented,dynamic planning freight transportation mode.Based on analyzing the transport principles of railway frieght,this paper defines the composition and classification of railway freight transportation mode,and then introduces the transportation plans which are the main component of transportation mode.We establish the market-oriented,dynamic planning freight transportation mode by constructing dynamic transportation plans between the basic transportation plans and the dispatching command,according to the dynamic transport demand of freight market and the change of transport resources.(2)This paper studies the formulation theories of dynamic railway transportation plans based on market orientation.Based on the point that the dynamic transportation plans are the core of the market-oriented transportation mode,we analyze the main technical contents of the dynamic plans,including dynamic wagon flow calaculation,freight train formation plan,freight train operating plan,locomotive operation implementing plan,vehicle operation implementing plan,driver crew operation implementing plan,station operation implementing plan,and also propose the formulating theroies of the dynamic plans from the aspects of significance,basis and method.(3)This paper studies the dynamic wagon flow calculating method based on implementing day.First,based on satisfying the timeliness requirement of distribution,an optimizing method for daily dynamic empty car distribution,espeically with considering multiple car types and capacity occupacy by loaded cars,is constructed to determine the movement direction and amount of emtpy cars.Then,on this basis,considering the preparation of dynamic transportation planning,a dynamic wagon flow calculating method based on Hidden Markov Model is designed to predict the position and technical status of dynamic wagon flows in different periods among the physical network.(4)This paper studies the freight train formation planning based on implementing day.We distinguish the heterogeneity of dynamic wagon flows and construct trian serivce time-space network based on blocking plan and train timetable.An integer programming model is constructed with minimizing the total costs of wagon flow movement,train operation,and shipment delay,and considering the constraints of wagon flow paths,flow conservation,operating number of trains,and transit time.To improve the solving efficiency,an improved simulated annealing algorithm is designed by increasing the solution number to achieve parallel search as well as by introducing multiple neighborhood structures.Finally,the effectiveness of the model and algorithm is illustrated by case studies from the real world.(5)This paper studies the train operating planning based on train path selection.We consider the transport characteristics of dynamic wagon flows,and propose to formulate train operating plan by selecting train paths in the basic timetable for the freight trains.A 0-1programming model is constructed by considering train uniqueness selection and train connecting constraints and minimizing the total freight train travel time and delay penalties.The numerical experiments on realistic instances demonstrate the proposed train path selection method can reduce the train travel time and ensure the freight delivery time.