Research On Trains’ Adjusting Considering Wagon Flow Connecting In Technical Stations

Technical station wagon flow organization and train adjustment in sections are the two elements which connect compactly and mutually influence each other, and then those two parts accomplish the target of wagon flow organization together by coordination. Train diagram and freight train formation plan are the crucial technical documentations which instruct the above-mentioned two elements. The freight train formationplan is used to collect wagons to form trains in technical stations, while the train diagram is used for stipulating train order. There is a progressive relationship between he train formation plan and the train diagram. In the daily dispatching and commanding, the dispatching department works out freight trainoperation plan conforming to the wagon flow volume and optimizing principal of wagon flow organization, and then divides and assigns the wagon flow and train flow organization task to technical stations and dispatching sections. The main task of technical stations\ is to continuouslyreceiving, marshallingand sending trains in accordance with the train formation and phase plan. Ensuring the implementation of planned train diagram and gaining high travel speed are the main duty of dispatching sections. This mode emphasis the coordination of technical station’s wagon flow organization with the dispatch sections. Technical stations’wagon flow organization belongs to the station level’s decision while the dispatching sections’belong to network level’s decision. Points are subjected to the whole. That, feature of China’s railway transportation organization mode, is certified to be reasonable and effective by long-term transportation practice. Freight train formation plan only contains the spatial attribute of the wagon flow. The wagon flow information is changed during the period of formulation and execution of freight train operation plan. Factors, such as deficiency of freight train operation plan and train running deviation and so on, can lead to low reliability of technical stations’ phase plan and increase of wagon staying time. Without any impact on train adjusting general target, taking the wagon flow connecting requirement as one of the following arrival train’s operation adjusting targets, makes the urgent needed wagon flow arrive the technical station on time or as early as possible through minor adjustment. That can reduce the waiting time of relevant wagons, raise the reliability of technical station’s phase plan, enhance point and line coordination, and then gain better transportation production effect.Based on the existed transportation organization mode, this paper proposed a research assumption:The operation of trains in sections could to some extent satisfy the need of wagon flow organization in technical stations. The feasibility and necessity of the assumption were verified by the technical station wagon flow organization model. The key problems, methods and theories involved were analyzed, and then the solution and procedure were put forward. The example showed that train operation adjustment considering wagon flow connecting requirement in technical stations to some degree would be favorable to transportation regions. The content of the paper is as follows:(1) Reviewed the research history and result of wagon flow organization in technical stations, train adjustment in sections and the relationship between them by great amount of documents and field investigation. The existing transportation organization mode and relevant research results had already emphasized the matching of wagon flow organization in technical stations to network train operation. However, the bilateral coordination researches are not many and not thorough.(2) Analyzed various wagon flow’s characteristics of flow allocation plan in technical stations from the aspect of wagon flow connecting. This paper established "section-technical station" wagon flow state transition equation which illustrated the constraint relation of time and space during the process of wagon flow organization. It built the technical station wagon flow organization model which is later simplified to a technical station wagon flow connecting model on the basis of partial ideal condition assumption. It designed and realized the algorithm in agreement with the feature of the model. It wrote simulation programs which described the impact of train arrival time changes on wagon flow connection in technical stations. Founded on the analysis and statistics of simulation result, the relevant conclusions of train delays’ influence on wagon flow connection in technical stations were proposed.(3) Based on the comparison of train diagram compilation, characteristics of train operation adjustment index, and researchhistory and results, this paper analyzed the factors and the relevant characteristic that should be taken into consideration while setting up the train adjusting index systemwhich considered the wagon flow connecting in technical stations.(4) This paper introduced the concept of "requiring wagons" and figured out the relationship between some arrival and departure train during the target period. It defined the possible 8 situations which could emerge while determining the adjusting target, and then proposed the definition of price of matching flow adjustment. It brought up the determining strategy of matching flow adjusting target according to different situations, and put forward the model and algorithm of the adjusting target to some comparatively complicated situation.(5) Combining with the matching flow adjusting target, this paper analyzed the possibility of adjusting and the influence of matching flow adjustment on transportation region and freight train travel speed in the same section. It analyzed the realization rate of matching flow adjusting target using work-flow net theory and method. Considering the feature of matching flow adjustment, it brought up the application scenarios, principle and measurement, and then built the matching flow model and designed improved genetic algorithm which is based on space searching.(6) Based on the analysis above-mentioned, this paper established a comprehensive model composed by three sub-models which are models of wagon flow connecting in technical stations, train operation adjusting target and matching flow adjustment. It took the train operation adjusting target as the intermediate model. Taking intermediate model as the main part without neglecting other sub-models was the coordination mechanism of the comprehensive model. Contrast to the large scale systems model’s hierarchical structure, solution with calculation by sub-systems and index evaluation could gain better satisfactory solution and less computation amount, and meet the comparatively high request of calculation speed, although it is more difficult to get the optimal solution.