基于双层规划的港口集疏运网络优化模型

Optimal Model of Port Gathering and Distribution Network Based on Bi-level Programming

为了提高港口集疏运网络中转站选址布局的合理性并优化货流分配,本文考虑实际环境中节点失效因素和多货种货主选择偏好因素对港口集疏运网络的影响,建立了双层规划模型刻画选址配流决策和货主偏好行为之间的关系。上层决策加入中转站失效惩罚成本,下层模型建立考虑货主选择偏好的用户均衡(user-equilibrium,UE)配流模型,用于估算运输网络中各路段的均衡货流量。根据模型特点设计了基于遗传框架并融合Frank-Wolfe算法的启发式算法,通过案例分析对模型及算法的有效性进行验证。结果表明:在模型中考虑节点失效能够显著提高港口集疏运网络的可靠性,并有效降低网络惩罚成本;考虑多货种货主选择偏好能够优化集装箱中转站选址布局及货流分配。

To improve the rationality of site selection and distribution of transfer stations in port gathering and distribution network and optimize the distribution of cargo flow,the influence of node failure factors and multi-cargo owners'preference factors on port gathering and distribution network was considered.A two-level programming model was established to describe the relationship between site selection and distribution decision and shippers'preference behavior.The transfer station failure penalty cost was added into the upper decision-making.The UE distribution model considering shippers'preference was established in the lower model,which was used to estimate the equilibrium cargo flow of each section in the transportation network.According to the characteristics of the model,a heuristic algorithm based on genetic framework and Frank-Wolfe algorithm was designed,and the validity of the model and algorithm was verified by case analysis.The results show that considering node failure in the model can significantly improve the reliability of port gathering and distribution network and effectively reduce the network penalty cost.The location layout and cargo flow distribution of container transfer stations can be optimized by considering the preference of multiple cargo owners.