Model and design of real-time control system for aerial variable spray

Abstract

The dosage sprayed upon per unit area is an important index to measure the effects of pesticide application. Owing to the fact that parameters such as flight height, flight speed, and spray swath can change at any given time, it is impossible to ensure a consistent amount of pesticide application per unit area during the course of aerial variable spray. In order to ensure a consistent amount of pesticide application per unit area, a set of control models of aerial variable spray using an unmanned aerial vehicle (UAV) was proposed, and the corresponding control system was developed based on the technology of aerial variable spray. According to the change of flight parameters, this system was able to adjust the opening degree of solenoid valve through the control model of aerial variable spray. After that, the amount per unit time would change to ensure a consistent amount of pesticide application per unit area, which effectively avoided the phenomenon of uneven pesticide application and improved the accuracy. According to the actual demand for the area in need of pesticide application, the operator can manually control the amount of pesticide applied and change the dosage sprayed upon per unit area to achieve a better effect. Through field tests, it was verified that the system has high accuracy of variable control. The deviation range was between 0.11% and 9.79%, which met the demands of agricultural aviation pesticide application. Furthermore, the system had strong stability for working continuously for more than 6 h at 30˚C to meet the environmental requirements of pesticide application via UAV. All the data related to the pesticide application were stored in this system, which provided a reference for the further study of the precision technology in pesticide application. The model proposed in this paper also provided a theoretical basis for the technology development of aerial variable spray.

Regulation of pesticide and fertilizer rates with applied by unmanned aerial vehicle

“…Expressions (10) and (11), determining the rate of application of the working fluid, show that with the differentiated application of BVS pesticides, fertilizers, plant growth regulators and other agrochemicals, the regulation of their rates (doses) can be carried out by changing the number of sprayers on the sprayer module boom, the area and, accordingly, the nominal diameter of the nozzle outlet sprayer, differential working pressure in front of the nozzles, UAV operating speed, working width, the ratio of the working width to the number of nozzles, characterizing the distance between adjacent nozzles -the spacing of the nozzles on the boom. It should be noted that the regulation of the application rates by changing the working width of the working in a practical aspect does not make sense.…”

“…Using expressions (10) and 11 Dependency Analysis H = h (V) shows that in the operating range of BVS-137 VIM flight speeds from 30 to 60 km / h, the rate of the working solution of nitrogen fertilizer changes from 120 to 60 l / ha, that is, it is halved. The rate of pesticide working fluid within 30-60 km / h varies from about 25 to 12 l / ha and also halves.…”

“…The analysis of the developed UAVs for plant protection showed that the pesticide spraying systems, as a rule, are integrated with the UAV flight control system and operate according to the specified GPS coordinates in accordance with the program for the processing of agricultural fields, however, the regulation of the working fluid flow rate is carried out by changing the operating pressure in the system or in the "on / off" mode [9][10][11][12]. This approach to regulating the flow rate of the working fluid is unproductive when differentiating the rates of application of working fluids of pesticides and fertilizers.…”

Design of Variable Spray System for Plant Protection UAV Based on CFD Simulation and Regression Analysis

“…The outdoor experimental results show that this system can spray in accordance with the demand in complex states. The spray system of Liu et al is uniform spray, and the control mode is empirical mathematical model [56]. This system has high stability, precision, and automation.…”

“…The spray system of Liu et al. is uniform spray, and the control mode is empirical mathematical model [ 56 ]. This system has high stability, precision, and automation.…”