Study On Optimization Of The Wagon's Pick-up And Delivery On Radial Private Line

As a member of a multitude of shunting operations at the station, operations of wagons' pick-up and delivery is one of its core operations. The organizational level of the operations of wagons' pick-up and delivery directly influences the traffic capacity of the road network and order of trains. Meanwhile, it's the major part of the station shift operations plan, whether the plan is reasonable or not directly affects the wagons' resident time at the station.In this paper, the theories and methods of the optimization of wagons' pick-up and delivery on the radial private line are studied. Based on deeply understanding the previous studies and systematically analyzing the characteristics of the problem of wagons' pick-up and delivery, the main work is as follows:(1) Systematically analyzing the operations object, factors, mode of organization, organization principle and classification of wagons' pick-up and delivery, the internal and external features of the system of wagons' pick-up and delivery are analyzed as well. Combined with the assignment scheme formulated by the station and the organization principle of operations, the optimization goals of wagons' pick-up and delivery on the radial private line are put forward: in the premise of ensuring successfully complete the task, to compress the wagons' resident time at the station and reduce the cost of pick-up and delivery, and to rationally utilize the locomotives in order to improve the turnover rate of wagons in the road network and reduce the operations' cost at the station.(2) Based on the principle that ensures the pick-up and delivery operations facilitate the marshalling operations and sufficiently exert the cohesive function of pick-up and delivery operations, the operations' procedure of wagons' pick-up and delivery on the radial private line is studied: firstly, generating the demand of pick-up according to the assignment scheme; secondly, arranging the time of pick-up and delivery reasonably on the condition that there are the demands of pick-up; thirdly, batching wagons' groups in order to improve the utilization of locomotives. Thus, the purpose of this paper is obtained: to seek a more reasonable scheme of pick-up and delivery which can not only compress the wagons' resident time at the station, but also reduce the cost of pick-up and delivery.(3) In this paper, each wagons' group is taken as a study unit, and the scheme of pick-up and delivery of each wagons' group and the allocation of locomotive are regarded as a whole goal to optimize. Firstly, according to the constraints of time windows of each wagons' group and optimization objectives determined before, the optimization model of the operation of pick-up and delivery charged by two locomotives and the optimization model of the operation of pick-up and delivery charged by multiple locomotives are built. Then, algorithm ? and algorithm ? based on real updating time of task are designed to solve the models mentioned above, which can dynamically batch the wagons' groups and allocate the locomotive for each batch of task. Finally, there are some algorithms designed to achieve some functions, such as batching, allocation of locomotives and updating of task set, etc.(4) In order to test the feasibility of the model and the effectiveness of the algorithms, different examples are designed for model I and model II, the algorithms are implemented to solve the two examples with the aid of computer. The results provide the scheme of pick-up and delivery and the allocation of locomotive for the staff, and the solving speed is very fast. The feasibility of the models and the effectiveness of the algorithms designed above are verified.