ABSTRACT

In this paper, we introduce the Electric Vehicle Routing Problem with Flexible Time Windows (EVRPFTW) in which vehicles are allowed to serve customers before and after the earliest and latest time window bounds, respectively. The objective of this problem is to assign electric vehicles to feasible routes and make schedules with minimum total cost that includes the traveling costs, the costs of using electric vehicles and the penalty costs incurred for earliness and lateness. The proposed mathematical model is solved by a column generation procedure. To generate an integer solution, we solve an integer programming problem using the routes constructed by the column generation algorithm. We further develop a linear programming model to compute the optimal times to start service at each customer for the selected routes. A number of well-known benchmark instances is solved by our solution procedure to evaluate the operational gains obtained by employing flexible time windows.

摘要

在本文中，我们介绍了带有弹性时间窗（EVRPFTW）的电动车辆路线问题，其中允许车辆在最早和最近的时间窗界限之前和之后为客户服务。该问题的目的是将电动车辆分配到可行的路线，并以最小的总成本制定时间表，其中包括旅行成本，使用电动车辆的成本以及因提早和延误而产生的罚款。所提出的数学模型通过列生成过程求解。为了生成整数解，我们使用列生成算法构造的路由来解决整数规划问题。我们进一步开发了线性规划模型，以计算选定路线的每个客户开始服务的最佳时间。