不确定需求下考虑货物时间价值的多式联运路径选择方法

Multimodal transport path selection method conside

为降低高价值时间敏感类货物的时间价值损失及合理规划多式联运路径,在不确定的运输需求情况下,探究货物时间价值对多式联运路径选择的影响。在考虑货物价值特性的基础上,通过鲁棒优化方法中的情景分析法建立以运输成本、货物时间价值成本及碳排放成本综合最低为目标和以节点作业硬时间窗等为约束的多式联运路径鲁棒优化模型。根据研究问题的特点,采用基于蒙特卡罗的灾变自适应遗传算法对模型进行求解,并以15个城市节点和公路、铁路、水路3种运输方式构成的联合运输网络为算例网络进行分析。研究结果表明:与不考虑货物时间价值相比,考虑货物时间价值的运输路径中铁路运输距离在运输总距离中的占比增加了17.28%,使得运输总时间降低12 h,节约货物时间价值成本16.19%。随着日平均衰减率的增加,在不同的衰减率范围内会选择不同的运输路径,同时选择增加铁路或公路运输距离占比以提高运输时效性,避免货物时间价值成本上升过快。需求的不确定使得运输成本、货物时间价值成本和碳排放成本分别增加了16.53%、3.44%和17.31%,最终导致运输总成本上升9.65%。研究结果可帮助决策者在根据实际需求情况和货物性质基础上,对需求量及衰减率进行估算,为其合理选择运输路径提供参考,避免造成货物时间价值损失过大。

To reduce the time value loss of high-value time-sensitive goods and rationalize multimodal transport paths,the influence of the time value of goods on multimodal transport path selection was investigated under uncertain transport demand.Based on the consideration of the value characteristics of the goods,a robust optimization model for multimodal transport paths was established by using the scenario analysis method in the robust optimization method with the objective of minimizing the combined transport cost,time value cost of goods and cost of carbon emission,and the constraints of hard time windows for nodal operations.According to the characteristics of the research problem,a Monte Carlo-based disaster adaptive genetic algorithm was adopted to discuss the model,and a combined transport network consisting of 15 urban nodes and three modes of transport-road,rail and waterway wee used as an arithmetic network for analysis.The results show that the rail distance as a percentage of the total transport distance increases by 17.28%for transport paths taking into account the time value of goods compared to those that do not,resulting in a 12-hour reduction in total transport time and a 16.19%saving in the time value cost of goods.As the average daily decay rate increasing,different transport paths will be chosen in different decay rate ranges.The increasing proportion of rail or road transport distance will be selected to improve transport timeliness and avoid the cost of the time value of goods rising too fast.The uncertainty of demand has increased transport cost,the cost of the time value of goods and the cost of carbon emission by 16.53%,3.44%and 17.31%respectively.Ultimately it can lead to a 9.65%increase in total transport costs.The results of the study can help decision makers estimate the demand and decay rate based on the actual demand situation and the nature of the goods,and provide a reference for their rational choice of transport paths to avoid excessive loss of time value of the goods.