冷链物流越库调度的拉格朗日松弛算法

Lagrangian relaxation algorithm for cross-dock scheduling & problems in cold-chain logistics

中文关键词  越库调度  冷链物流  拉格朗日松弛  次梯度算法

英文关键词  corss-dock scheduling  cold-chain logistics  Lagrangian relaxation algorithm  Subgradient algorithm

中文摘要

      为了解决越库(cross-docking)在冷链物流中的应用问题，提出了基于拉格朗日松弛算法的冷链物流的越库调度方法。首先进行了问题域的描述，并基于问题域以最小化卡车等待时间和越库内部运输成本为目标，建立越库调度的数学模型。然后，提出了针对越库调度模型的拉格朗日松弛算法，松弛复杂约束后根据决策变量将松弛问题分解为若干子问题，采用次梯度算法求解松弛模型。最后，对各种不同规模的越库模型进行仿真实验，并与传统的贪婪算法进行对比，结果表明，所提出的调度算法可以在较短时间内获得良好的近优解。

英文摘要

      In order to effectively solve the scheduling problems in cold-chain logistics, a scheduling method of cross-dock is proposed based on a Lagrangian relaxation algorithm. Firstly, a scheduling problem domain of cross-dock of cold-chain logistics is described and then a mathematical programming model is constructed with objectives of minimizing total truck waiting time and inner cross-dock transportation cost. A Lagrangian relaxation algorithm aiming at cross-dock scheduling is developed, which decomposes the relaxed problem into several sub-problems. A Subgradient algorithm is introduced to solve these sub-problems. Finally, simulation experiments of different problem scales are carried out to analyze the proposed algorithm and compared with a Greedy algorithm. Results indicate that the proposed algorithm can obtain satisfactory near-optimal solutions within the reasonable time.