铁路集装箱空箱调配分布式鲁棒优化方法研究

Research on Distributionally Robust Optimization Method for Railway Empty Container Repositioning

基于中国铁路“集装箱运输全程追踪系统”中各计划周期(5 d)的集装箱运用数据,定义集装箱办理站发出重箱与到达重箱的差值为“净空箱需求”或“净空箱余量”,并设计其分布集合,考虑办理站空箱堆存能力,构建全路空箱调配分布式鲁棒优化模型。模型优化目标为最小化空箱走行距离,并实现净空箱需求/余量在最不利情况下,集装箱办理站仍能以一定服务水平满足装箱或接车需求。模型转换后采用Cplex求解,全路35 t敞顶箱空箱调配案例的测算结果表明:所提方法能够满足“中国国家铁路集团有限公司-铁路局集团公司”两层级调配方案编制的需求;在考虑各办理站的基础装箱需求上,模型在部分服务水平参数组合下能够显著促进典型空箱“排空站”在保证发重的前提下往外排出空箱,有利于促进供需不平衡条件下空箱的有序周转。

Based on the container utilization data from the China Railway“Container Transportation Full-Process Track-ing System”with a five-day planning cycle,this study defined the difference between the dispatched and arrived loaded containers at container handling stations as“net empty container demand”or“net empty container surplus”,and de-signed the sets of probability distribution for this net empty container demand/surplus.Based on the empty container storage capacity of container handling station,a distributionally robust chance-constrained empty container repositioning model was constructed for the whole railway system.The model intended to minimize the empty container repositioning distance while ensuring that handling stations could meet the demand for dispatching loaded containers and handling ar-rived loaded containers even in the worst-case scenario of net empty container demand and net empty container surplus at a certain service level.After model conversion,Cplex was used to solve the problem.The case results of 35 t open-top empty container repositioning plans across the railway system show that the proposed approach can fulfill the requirements for formulating repositioning plans of the current empty container repositioning mode.Taking into account the fundamental demand of loading containers at each handling station,the model,under certain combinations of service level parameters,can significantly promote the typical“discharging empty container stations”to discharge own empty containers outside the station while ensuring the dispatch of loaded containers.This facilitates the orderly circulation of empty containers under conditions of supply⁃demand imbalance.