货物运输“公转铁”与铁路车流径路联合优化模型

Joint Optimization Model for Diverting Freight Flow from Road to Railway and Routing Railway Car Flow

货物运输“公转铁”是我国当前交通运输发展的重要战略,而高质量落实该战略需要解决一系列复杂的运输组织优化问题。首先分析公铁货流转移与铁路车流组织之间的联系与相互影响机理,据此构建以公铁两网综合物流成本最小化为目标的公铁货流转移与铁路车流径路联合优化模型。模型通过构造连续型决策变量实现对货流转移量的优化,同时通过构造0-1决策变量和辅助0-1决策变量实现各OD根据货流转移后的发送量按照其适用的车流组织模式进行径路优化。针对模型的非线性特征,采用二次替代的方法将模型转化为线性规划模型。最后通过算例验证了模型的有效性。

Diverting freight flow from road to railway is an important strategy for the development of transportation in China.The implementation of the strategy with high quality requires to solve a series of complex optimization problems of transportation organization.Firstly,this paper analyzed the relationship and the mechanism of interaction between road-railway freight flow diverting and railway car flow assignment.Then,aiming at minimizing the total logistics cost of road and railway network,the joint optimization model for diverting freight flow from road to railway and routing railway car flow was developed.In the model,continuous decision variables were designed for optimizing the freight flow diversion from road to railway.Meanwhile,binary decision variables and assistant binary variables were designed for optimizing the car flow path according to the corresponding rule based on the freight volume after the diversion of the freight flow.Based on the non-linear characteristics of the model,a quadratic substitution method was used to transform the model into a linear programming one.Finally,the effectiveness of the model was verified by solving a numerical example.