Drones have recently been suggested as a means of performing last-mile deliveries, as they have several advantages compared to traditional delivery vehicles. A recent research avenue is to adopt a hybrid truck-drone delivery system that integrates drones with traditional delivery methods such as trucks. This paper deals with the problem of optimizing the delivery operation of a truck working in tandem with a drone capable of visiting multiple customers per dispatch. We also introduce practical attributes such as allowing the truck to launch and retrieve the drone from both customer and non-customer nodes as well as permitting cyclic and acyclic drone operations. An integer linear programming model is first formulated followed by the development of an effective variable neighborhood search (VNS)-based approach. The novelty of the latter is that it incorporates an effective categorisation of neighborhoods due to their large number that is needed while retaining their individual impact through an adaptive selection scheme. The performance of this powerful VNS-based heuristic is empirically assessed against three variants of the VNS. The VNS heuristic was also shown to be flexible and effective at handling the issue of synchronization. A sensitivity analysis, based on some of the critical parameters of the drone, is conducted alongside highlights of some interesting insights.

中文翻译：

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具有多次访问、多次发射和检索位置的混合卡车无人机送货系统：数学模型和具有邻域分类的自适应变量邻域搜索

无人机最近被建议作为执行最后一英里交付的一种手段，因为与传统的交付车辆相比，无人机具有多种优势。最近的一个研究途径是采用混合卡车-无人机送货系统，将无人机与卡车等传统送货方式相结合。本文讨论了优化卡车与无人机协同工作的送货操作的问题，该无人机能够每次调度拜访多个客户。我们还引入了实用属性，例如允许卡车从客户和非客户节点发射和回收无人机，以及允许循环和非循环无人机操作。首先制定了整数线性规划模型，然后开发了基于有效变量邻域搜索（VNS）的方法。后者的新颖之处在于，它结合了对社区的有效分类，因为需要大量的社区，同时通过适应性选择方案保留其个体影响。这种基于 VNS 的强大启发式方法的性能是根据 VNS 的三种变体进行经验评估的。 VNS 启发式方法在处理同步问题方面也被证明是灵活且有效的。基于无人机的一些关键参数的敏感性分析与一些有趣的见解的亮点一起进行。