Drone-Based Material Transfer System in a Robotic Mobile Fulfillment Center

Deploying unmanned aerial vehicles, also known as drones, for final-mile delivery in logistics operations has inspired this research. One conceivable scenario is to use the drone to transfer jobs in a robotic mobile fulfillment center. Each job might be characterized by origin, destination, time window, and precedence relation. In particular, a take-away conveyor is continuously pushing forward shipping cartons, wherein drones must pick up jobs and drop them off to the cartons within the time window since the cartons would be closed and labeled at the end of the conveyor. Furthermore, each job contains two subtransfers for drone: flight from drone's current location to pickup location and flight to dropoff location. Two exact approaches are proposed-a mixed integer programming and a constraint programming-and tested for a real-time perspective.

I. Introduction

Arobotic mobile fulfillment system (RMFS) is a new type of automated storage and part-to-picker order picking system. It is particularly suited for e-commerce distribution centers that handle strong demand fluctuations and large assortments of small products [30]. Fig. 1 depicts different mobile robots used in RMFS. Fig. 1.

Transbots for pickup and dropoff tasks: Amazon [40] (left), Berkshire Grey [4] (middle), and Ocado [35] (right).