| Based on PWM (Pulse Width Modulation) technology, the variable pesticide spraying system of UAV
(Unmanned Aerial Vehicle) was promoted, which consisted of kits, nozzles, pump and spray controller. The pump operating
time was varied by the duty cycle of the PWM signal, so as to change the spray flow. According to the constant flow
indicators of spraying pesticides and the coverage sprinkler system, the PWM frequency was determined to 1 Hz. A cubic
polynomial relationship model between duty cycle and spray flow was established, and the coefficient of determination
reached 0.9944. Experiments under flow rate indicator condition of 0.3, 0.4 and 0.5 L/min were done, and the results
showed that the errors between sprayed and target flow were 8.66%, 4.50% and 1.60%. Variable spray control objective
was achieved. |
