Abstract:

The trend of green logistics pushes the use of electric vehicles into cold chain logistics. Concerning the problem that maintaining a low temperature environment requires a lot of energy in electric vehicle cold chain distribution， as well as the phenomena that the limited driving range and long charging time of electric vehicles make high operation cost， the Refrigerated Electric Vehicle Routing Problem （REVRP） in electric vehicle distribution was thought deeply. Considering the characteristics of electric vehicle energy consumption and the charging requirements of social recharging stations， a linear programming model was developed with the objective of minizing total distribution cost， and the objective function was composed of fixed cost and variable cost， in the variable cost， transportation cost and cooling cost were included. The capacity constraints and power constraints were considered in the model， and a Hybrid Ant Colony Optimization （HACO） algorithm was designed to solve this model. Especially， more attention was paid to designing transfer rules suitable for social recharging stations and four local optimization operators. Based on improving the Solomon benchmark examples， the small-scale and large-scale example sets were formed， and the performance of ACO algorithm and the optimization operators were through experiments. The experiment results show that ACO algorithm and CPLEX （WebSphere ILOG CPLEX） solver can find the exact solution in the small-scale example set， and ACO algorithm can save the operation time by 99.6% . In the large-scale example set， compared with ACO algorithm， HACO algorithm combing the four optimization operators has the average optimization efficiency increased by 4.45%. The proposed algorithm can obtain a feasible solution for REVRP in a limited time.

Key words: cold chain logistics, logistics distribution, electric vehicle, Vehicle Routing Problem (VRP), ant colony optimization

摘要：

用电动汽车进行冷链物流配送符合绿色物流的发展趋势。针对电动汽车冷链配送需消耗更多能源以维持低温环境，而电动汽车续驶里程短、充电时间长，致使运营成本高的现象，思考了电动汽车配送中的冷链车辆路径问题（REVRP）。考虑电动汽车能耗特点和社会充电站的充电需求，构建了以总配送成本最小为优化目标的线性规划模型，而目标函数由固定成本和可变成本构成，其中可变成本包含运输成本和制冷成本。模型考虑容量约束和电量约束，并设计混合蚁群（HACO）算法对其进行求解，其中重点设计了适合社会充电站的转移规则以及4种局部优化算子。在改进Solomon基准算例的基础上，形成了小规模和大规模两个算例集，并通过实验比较了蚁群（ACO）算法和局部优化算子的性能。实验结果表明，在小规模算例集中，传统ACO算法与CPLEX求解器均能找到精确解，而ACO算法在运算时间方面可节省99.6%；而在大规模算例集中，与ACO算法相比，结合4种局部优化算子的HACO算法的平均优化效率提升了4.45%。所提算法能够在有限时间内得出电动汽车REVRP的可行解。

关键词: 冷链物流, 物流配送, 电动汽车, 车辆路径问题, 蚁群算法