Flying Sidekick Traveling Salesman Problem in Truck–Drone Team Logistics with Energy Issues

Abstract

Last-mile delivery has become increasingly important in recent years because of changes in customer needs. In this study, single-truck–multi-drone team logistics is considered. A mixed integer mathematical model is developed for the flying sidekick traveling salesman problem, a single-truck–multi-drone problem by considering technical and energy issues. Two different objective functions are used in the model. The first objective function is to minimize the sum of arrival times. Minimizing the sum of arrival times for customers also minimizes the distance traveled by the vehicles and, accordingly, the cost. The second objective function is to minimize total tardiness. A dataset is generated to test the proposed model. Trade-offs between the results for the two objective functions are analyzed. The technical requirements of the drone, energy limits, and fleet size are considered in the proposed mathematical model. The effects of the flight ranges of the drones are investigated with respect to the energy constraint. It has been observed that changes in the number of customers and drones affect the results of the objective functions. The total arrival time and tardiness decreased with increasing number of drones. Thus, the number of deliveries by truck decreases for customers. In addition, the advantages of this hybrid approach have been proven by comparing situations where only land vehicles are used with truck–drone team logistics.