Energy Consumption and Greenhouse Gas Emissions of Autonomous Aerial and Ground Vehicles for Last-Mile Delivery

The last mile of package delivery, representing how a package is transported from a local warehouse or business to a customer’s home, is an important factor in the transportation sector's energy consumption and greenhouse gas (GHG) emissions. In the past decade, the demand for last-mile delivery increased with the growth of online shopping. Many companies have been developing autonomous vehicles to meet this demand, which could be an opportunity to reduce the environmental footprint of lastmile deliveries. In this dissertation, I assess the energy consumption and GHG emissions of autonomous uncrewed aerial vehicles (UAVs) and uncrewed ground vehicles (UGVs) for last-mile delivery. I present a reproducible experimental protocol to instrument a quadcopter drone to collect and validate data on wind, state conditions, and power consumption throughout a package delivery flight. I then characterize UAV energy consumption under a variety of flight regimes and conditions and develop energy models based on empirical data and first-principles analysis to predict the energy consumption of UAVs and UGVs for last-mile delivery. I compare the energy consumption and GHG emissions of these vehicles with different transportation modes: medium-duty trucks, small vans, and electric cargo bicycles. I show that, depending on the delivery intensity and electricity emission factor, UAVs and UGVs can reduce energy consumption by more than 90% and GHG emissions by more than 80% per package delivered, relative to traditional diesel truck delivery. In addition, I develop two methods to place charging stations to increase the range of drones: a sequential placement approach with relatively low computational cost and a reinforcement learning approach to inform the site of multiple stations simultaneously, which returns better outcomes at higher computational costs. The findings presented in this dissertation suggest that UAVs and UGVs have potential to reduce the energy consumption and GHG emissions of last-mile deliveries, and the methods provide decisionmakers and policymakers with the tools to investigate the social and environmental benefits of exploring UAVs and UGVs as last-mile delivery vehicles.