Research on optimal size routing operation scheme based on multi-objective programming model

Aiming at the planning problem of the operation scheme of large and small interroute trains, this paper establishes a mathematical model based on multi-objective nonlinear integer programming, entropy weight TOPSIS and the strategy of “selecting the best among the best”, and solves the optimal operation scheme for the enterprise to minimize the operating cost and maximize the service level. Furthermore, the model is optimized according to the solution results, and specific suggestions are provided for the enterprise. First of all, passengers are classified, and the six categories of passengers are divided into two categories of passengers, so that all types of passengers are naturalized into the same system. Then, by establishing the objective function and constraint conditions, the multi-objective nonlinear integer programming model pair model is established. Then genetic algorithm was used to solve the optimal scheme and found that its effect was not ideal. According to the characteristics of the solution set, 48 schemes satisfying the constraint conditions were enumerated by enumeration method. Then, the TOPSIS method based on entropy weight is used for comprehensive evaluation of 48 schemes. After eliminating the inferior solutions with obvious low scores, the entropy weight method is used for secondary weight determination of the remaining 12 schemes. Then TOPSIS method is used to classify the $\mathbf{4}$ objective functions into a dimensionless evaluation system for evaluation, and the optimal opening scheme is solved. The objective function is modified, the definition of retention rate is introduced. A new model is established, the optimal running scheme is obtained when the number of trains is just reduced by one group by decreasing value, and the parallel running diagram with equal intervals is formulated. In this paper, the change rate of train time and the number of trains are calculated by considering multiple objectives. The following suggestions are given to enterprises: on the basis of reducing the minimum parking time standard, a certain “reaction time” is increased; we need to increase the train capacity to a certain extent to reduce the frequency of departures; The starting and terminating stations of minor trains shall be located at stations with a large number of passengers on and off.