Research On EMU Scheduling For Radial HSR Network

Since the Beijing-Tianjin inter-city railway was put into operation, Chinese high-speed railway (HSR) has experienced a great-leap-forward development. By the end of 2015, the length of Chinese HSR reached to 19,000 km, accounting for over 60% of all countries’. During the development process of HSR, radial networks have formed around the railway hubs, which have laid a good foundation for the mixed operation of EMU.Firstly, the paper analyzes the current EUM operation status, including EMU operation characteristics, management system, operation mode and maintenance rules. The impacts of the radial network on EMU operation are researched and the mixed EMU operation mode for radial networks is proposed, which means that EMUs can be allotted between different stations in a railway hub and between different HSR lines in a station. Besides, the classifications, influence factors and compilation rules of EMU scheduling plan is proposed.Secondly, the EMU scheduling problem is transformed into a typical multiple traveling salesman problem (MTSP). The objective function is the least number of EMU. The constraint conditions include the connections of time and space, mileage-constrained maintenance and time-constrained maintenance. Besides, allocations between different stations in a hub, allocations between different HSR lines as well as EMU types are also considered. Furthermore, a week is regarded as a period to schedule the EMU operation and maintenance.Thirdly, multiple solving algorithms for MTSP are compared and Ant Colony Algorithm (ACA) is selected. During the solving process, the roulette is used to select the backward train path and the cycle number is used to stop the calculation. Besides, the basic evaluation indexes and coordination evaluation indexes are proposed.Finally, a week’s train path data of Shanghai hub is collected for case study. In order to validate the effects to solving quality and convergence rate of different operation modes, exchanging EMU types, different backward train path number, parameter p, parameters α and β, a series of experimental schemes are designed. The experimental results indicate that, EMU allocations between different stations in a hub and between different lines in a station can decrease the EMU operation number. So does exchanging EMU types. For current train diagram, when the backward train path number is 275, parameter p is 0.7, parameter a is greater than β and both of them are valued moderately, the solving quality and convergence rate are relatively superior. For a better solution, three best experimental schemes are tested again. The least EMU number is 370. All in all, the mixed operation of EMU for radial HSR network can decrease the EMU operation number; ACA can be used to solve the problem and reasonable parameters can improve the solving quality and convergence rate.