Research On Optimization Method Of Empty Railway Car Dynamic Dispatching Under "Real-Freight System"

To expand railway freight transport market, China takes the reform of "Real Freight System" as an important content during the process of railway transportation reform. Railway freight transport will be organized according to the market demands instead of previous plan which we used before. Principle of "open to the market and load once the freight arrived" is put forward during the reform which set an even higher demand to the dispatching of empty railway car. Under this circumstance, how to maximize the transport profits has been an essential problem for transport companies when the customer’s demands are met and the empty cars are utilized effectively as well. Combined with China’s transport reality and freight transport demands, the problem of empty railcar’s dynamic dispatching is studied in this paper taking other countries’ experiences as references listed follows:Firstly, this paper analyzed basic theory about empty railcar dispatching under the "Real Freight System" including China’s freight transport reform and empty car’s dispatching. On the aspect of transport reform, reasons and contents about railway freight transport reform are firstly elaborated as well as its meaningless. And then comparisons are made in freight business process before and after the freight reform, showing that the business process can be much simplified so as to improve the transport effectiveness under the "Real Freight System". To ensure that the freight can be transported and arrived at destination on time, analysis about the influences of "Real Freight System" on train’s organization along lines is made. Empty railcar’s sources, on the aspect of car’s dispatching, dispatching principle and method, the necessity for dynamic dispatching and the process of railcar’s dispatching are analyzed next. Then, the influences on empty railcar’s dispatching is summarized that exerted by the "Real Freight System".Secondly, the paper focuses on the study of the dynamic dispatching problem. Optimization model for empty railcar’s dynamic dispatching is built based on the service time-space network both considering the daily empty and loaded railcar’s organization and the new requirement on transport organization from "Real Freight System". The model aims to maximize the total profit of the transport company. Considering the multi-type of railcars and the demands’uncertainty, some revises are made to the model. Thirdly, a new intelligent algorithm-Microevolution Algorithm (MA) is put forward in this section considering the solving complexity once the rail network is large. Basic theories about MA are first given and then the algorithm to solve the optimization model is designed.Finally, the model and algorithm’s effectiveness are verified by a real example. The solving result and the algorithm are analyzed finally which provides a valuable reference to the practical work of dispatching empty railcars.