Determining the efficiency of plant spraying using a quadcopter-type unmanned aerial system (UAS)

The research target is the technology of applying liquid agents used in crop growing by using an unmanned quadcopter-type aerial system. Spring wheat was treated by using the XAG P100 quadcopter with centrifugal nozzles. The coverage area of a plant leaf with a sprayed liquid was taken as an optimization criterion. The influence of the following factors was evaluated: flight altitude, flight speed, drop diameter, application rate, and the distance from the axis of the flight path to the material selection point (operating width). The effectiveness of spraying was evaluated by the surface area of the wheat leaf sprayed with the solution using DropSight® technology. A coloring agent that fluoresces in the ultraviolet spectrum was added to the water. The leaves of the plants covered with the solution after the flight of the quadcopter with the nozzles turned on were collected and placed in a special chamber equipped with an ultraviolet lamp. Photographs of the leaves were taken from both sides - top and bottom. The obtained photographs were processed using special software that evaluated the area of the leaf covered with the solution as a percentage of the total area. Based on the result of the experiment, a regression equation was obtained, the significance of the factors was assessed, and the possible theoretical maximum of the optimization criterion was obtained. The most significant of the five factors were two: the rate of the agent and the distance from the axis of the flight path to the sampling point. The greatest uniformity of the solution distribution over the operating width is achieved with the minimum values of all factors at their levels used in the experiment. The values of the factors at which the maximum value of the optimization criterion is achieved are given.