Research On Cargo Transportation Organization Scheme For Planning Railway Based On Space-time Tunnel

The quality of transportation services is an important basis for cargo owners to choose transportation modes,and ensuring timeliness and punctuality has become the main means for various transportation modes to improve market competitiveness.Railway transportation has been focusing on space utility improvement,and timeliness and punctuality have become the shortcomings that restrict its further development.Implementing the planning railway transportation organization mode with the ultimate goal of ensuring the timeliness of cargo transportation is an effective way for railway to adapt to market development and improve service quality.This paper designs the planning railway transportation organization scheme based on space-time tunnel and constructs the mathematical model for programming,which helps to promote the theoretical research and practical application of planning railway transportation organization and provides reference solutions for railroads to guarantee the timeliness of cargo transportation.This paper firstly compares the current research status of railway transportation organization technology and transportation service optimization,and proposes research contents and technical lines.Secondly,it analyzes the basis of transportation organization scheme implementation,deeply explores the similarity between space-time tunnel and railway transport,discusses the production process of railway space-time tunnel transport,constructs the preparation method of transport organization scheme based on space-time tunnel,and proposes the preparation ideas of minimum cargo delivery time measurement,allocable reserved time calculation and blocking and timetabling combination scheme.Third,considering the uncertainty of cargo delivery time,the PERT-based cargo delivery time measurement method is proposed.The nature of the reserved time allocation problem is analyzed,the reserved time allocation problem is transformed into a knapsack problem,the knapsack parameters determination method and solution algorithm are designed,and the calculation cases are analyzed to verify the validity of the model.Fourthly,the blocking and timetabling combination model based on space-time tunnel is established,and the genetic algorithm is designed to solve the model with the objective function of minimizing the cost of traffic reassignment,train operation cost,traffic succession cost and saving logistics and storage cost,taking into account the traffic reassignment constraint,train running line constraint and reserved time allocation constraint.Finally,a case study of the Northeast local railway network is conducted to test the validity of the model and algorithm.The results of the case study show that the traffic reshuffling scheme,cargo train operation scheme and reserved time allocation scheme obtained from the blocking and timetabling combination model based on the space-time tunnel can optimize the railroad transportation process,and the on-time delivery of goods on the railway network is improved by 7.5%,and the quality of railway transportation services is significantly improved.