Experimental data survey analysis to assess UAVS characteristics to spray crops in precision farming

The aim of the study is to conduct a review analysis of experimental data to evaluate the performance of UAVs for crop spraying in precision agriculture. The presented experimental data reflects the results of testing and evaluating the effectiveness of UAVs for pesticide spraying in China, where UAVs for crop protection have been rapidly developed in recent years. The data are presented for four commonly used UAV types in China: single-rotor gas-powered UAVs 3WQF120-12 and 3CD-15; six-rotor electric UAV WSZ-0610; single-rotor electric UAV HY-B-15L. Although these UAVs have different characteristics, the analysis of experiments conducted by Chinese researchers provides objective information on their effectiveness in pesticide spraying, and also gives an idea of the development status of such UAVs in China. The spray zones, permeability, droplet density and UAV efficiency in field conditions for given areas of treated sites were studied. The analysis of typical UAV malfunctions during transport and technological operations during crop spraying is presented. The analysis of the failure rate of UAVs of the considered types showed the time spent on troubleshooting from the total operating time. The data on the time spent on ground handling, preparatory work, route planning are presented. The net operating time was about 30 %. A review of the works in the considered research area allows us to state that, in general, the high efficiency of UAVs has not been fully achieved. Both the characteristics of the UAVs themselves used for crop spraying and the transport and technological operations, including ground handling and flight control, still require further improvement. In order to increase the efficiency of UAVs and achieve satisfactory values for the operations performed, it is important to conduct preliminary studies to assess the time and resource costs of implementing the UAV transport and technological cycle. This will ensure optimal and safe aerial spraying in precision farming systems.