Coordinated optimization research of train diagram and maintenance window on plateau railway

In response to the conflict between the train diagram on the plateau railway and maintenance window, a coordinated optimization of the train diagram and maintenance window for the plateau railway trains is conducted. Considering constraints such as train service level, train operation, train diagram equilibrium, and maintenance window time, a multi-objective mixed integer programming model is established to minimize the total travel time of trains and maximize the total duration of maintenance windows. A multi-objective solution algorithm based on layered sequences is designed, and Python programming is utilized to invoke the Cardinal optimizer (COPT) solver to solve the model. Taking a section of the plateau railway as a case study, the effectiveness of the model is verified. The results indicate that the proposed coordinated optimization model for the train diagram on the plateau railway and maintenance window, under the consideration of constraints such as train service level and train diagram equilibrium, can simultaneously minimize the total travel time of trains and maximize the duration of maintenance windows. The train diagram based on the optimal solution shows that the coordinated optimization results of the train diagram and the maintenance window are more in line with the actual passenger transport production operation needs of the plateau railway. The research findings provide a scientific basis for railway operation management departments to further optimize train diagram and maintenance window arrangements.