Study On Optimization Of Train Routing Scheme Of Urban Rail Transit With Cross-Line Operation

In order to create a networked operation model and further achieve the strategic goal of becoming a transportation powerhouse,the rail transit industry will face severe challenges.The problems of passenger flow congestion at interchange station,unmet travel demand of passengers for medium and long distances,poor travel experience of passengers,imbalance of space-time distribution of passenger flow and low matching of transport capacity are becoming increasingly prominent.Therefore,achieving networked operation of various lines is the future development trend of rail transit.Given this background,combining different operating modes based on various rail transit lines and passenger flow conditions to achieve cross-line operation between different lines is of great practical significance for creating a networked and collaborative rail transit system.In this paper,based on the cross-line reconnection mode of traffic operation,in-depth discussion of urban rail transit cross-line train traffic scheme optimization related issues.Analyzed the key issues of urban rail train routing schemes under cross-line operation conditions;Established a model for passenger travel path selection and passenger flow allocation under cross-line operation organization;Designed an optimization model and algorithm for cross-line train routing schemes;The effectiveness of the model and algorithm was verified by an example.The main research content and conclusions of the paper are as follows:(1)The key issues of urban rail train routing plan during cross-line operation have been condensed.Analyzed the advantages and disadvantages of cross-line routing and the necessity of conducting cross-line operation,and studied the technical difficulties of cross-line operation from the aspects of line and station forms,vehicles,power supply,and signals;Summarized the principles,influencing factors,and preparation steps of the routing plan,laying a theoretical foundation for the establishment of an optimization model for cross-line train routing plans.(2)Based on the bounded rationality behavior of passengers,the prospect theory is used to build the passenger travel route selection and passenger flow allocation model under the cross-line operation organization.Design an effective path search algorithm for the multiple choice behavior of passenger travel,obtain the foreground values of each feasible path through prospect theory,and calculate the path selection probability and passenger flow allocation based on the logit model.Finally,validate the model.The results show that the improved path search algorithm can obtain paths that are in line with passenger travel,and the passenger flow allocation is also more in line with the actual travel of passengers.(3)We have constructed an optimization model for cross-line train routing schemes and designed intelligent optimization algorithms based on the uniqueness of the model.Considering the operational situation of rail transit,with the goal of minimizing both enterprise operating costs and passenger travel costs,and with constraints such as the upper limit of vehicle base,traffic capacity limitations,departure frequency,departure interval,and passenger flow demand,the optimization of cross-line route turn back stations,departure frequency,and number of vehicles in each route formation is carried out simultaneously.In the process of algorithm design,the passenger travel route selection and passenger flow allocation model are embedded into NSGA-Ⅱ algorithm to solve the model.(4)The feasibility and effectiveness of the model and algorithm in this paper are verified by an example.Taking Harbin Rail Transit Lines 1 and 2 as the research object,the transfer passenger flow of the line network is analyzed,and the cross-line direction is defined as Jiangbei University City-Harbin South Railway Station.In the Pareto solution set of optimization results,a compromise solution was selected to compare with the single line independent operation scheme.It was found that the cross-line reconnection routing operation mode can save the total operating cost of the enterprise by 6.98%,including 8.44% in acquisition cost and 5.91% in travel cost;The total cost of passenger travel was saved by 9.32%,including 29.72% reduction in congestion costs,41.91% reduction in transfer costs,and a 10.8%increase in waiting costs.The results show that during peak hours in the morning,the main line operates multiple group trains and the cross-line operates small group trains.This can not only meet the travel needs of passengers,but also reduce the number of vehicle usage,making the transportation capacity more compatible with passenger flow.(5)Through sensitivity analysis,reveal the complex mechanism of different parameters on model optimization results.The results show that:(1)The upper limit of load rate should be selected according to passenger satisfaction and enterprise operation management.(2)The greater the intensity of cross-line passenger flow,the more significant the superiority of crossline reconnection mode.(3)The distance between cross-line turnback stations is not too long or too short.(4)When enterprises pay attention to economic benefits,they will choose the A marshalling scheme,and when they pay attention to public benefits,they will choose the B marshalling scheme,but both marshalling types are better than the single fixed marshalling scheme.(5)Passenger travel cost is most sensitive to risk preference coefficient ?.