考虑订单取件时间和柔性时间窗的取送货车辆路径问题

研究了同城配送中考虑订单取货时间和柔性时间窗的取送货车辆路径问题,考虑同城配送中订单起终点,订单取货时间和订单配送的柔性时间窗,车容量限制等因素。首先构建以配送成本与超时惩罚成本之和最小化为目标的混合整数线性模型。其次,设计了含多种有效不等式及其对应分离算法的改进分支切割算法对该模型进行精确求解。最后通过实验测试分析了不等式的性能,验证了算法的有效性,实验表明适当的减少车辆数和增大装载能力能够有效的减少成本。

Pickup and Delivery Vehicle Routing Problem with Order Release Dates and Flexible Time Windows

This paper studies the pickup and delivery with order release dates and flexible time windows in the urban distribution, which consideres the factors such as orders’ pickup positions, orders’ delivery positions, order release dates, flexible time windows and vehicle capacity. A mixed integer linear model is provided to minimize the sum of distribution cost and timeout penalty firstly. Secondly, an improved branch-and-cut algorithm considering a set of valid inequalities and corresponding separation algorithms is designed to solve the model accurately. Finally, we analyze the effect of inequality on the performance of the algorithm, and verify the effectiveness of the algorithm by testing several sets of examples. Moreover, the results also show that appropr; abely reducing the numlet of vehicles and incteasing the loading capacity can effectioely reduce the lost.