Two-Echelon Location Selection and Unmanned Aerial Vehicle Assisted Vehicle Routing Problem

In recent years, the potential use of Unmanned Aerial Vehicle (UAV) technology in logistics processes and the rapid developments in this field have made UAV-assisted routing problems an important research topic. In this paper, we consider a two-echelon location selection and UAV-assisted vehicle routing problem. In this problem, trucks leave from the main depot with their packages and UAVs, move through potential service points (mobile depot), and return to the main depot. At each mobile depot, UAVs are launched from the truck to service the customers, and the trucks wait for the UAVs to complete their service and return. The UAVs are capable of making multiple trips between the mobile depot and customers, carrying only one package at a time. The objective is to minimize the maximum tour time. In this paper, a new problem, which involves a multi-truck structure and multiple launches of UAVs from a mobile depot, is investigated for the first time to the best of our knowledge in the literature. A mixed integer linear programming model is proposed to solve the problem. In order to evaluate the performance of the proposed mathematical model, the number of trucks is determined as one and two, experimental analyses are performed and the results are reported in detail.