Comparison between an in-flight UAV refueling platform and ground-based vehicles for plant protection product distribution

Limited payload range generally caused by the poor weight-energy performance, flight autonomy, manual replacement of spent batteries, and agrochemical tank refilling procedure are limiting factors affecting UAVs' agrochemical distribution. This work aims to evaluate the effectiveness of agrochemical distribution by a UAV operated by a reactive robotic payload replacement (M.A.R.S.) platform and compare it with ground-based distribution systems in a viticulture scenario. The work considers a hybrid technology UAV with an onboard gasoline-powered electric generator, characterized by an "in-flight" refill of fuel and agrochemicals without the need for landing. Results report a limited ability of the aerial system to cover large areas with a single tank, balanced by 2.3 minutes to perform a tank refill, significantly less than ground-based distribution systems. The volumes of plant protection products delivered per hectare by the aerial platforms are more suitable for low-volume treatments but they can be logistically advantageous because of their rapid response and lack of impact on soil and crops. The proposed approach represents a solution for UAV implementation for spraying operations on vineyards and opens new scenarios for large areas treatments.