Abstract:Aiming at the low efficiency of rice panicle fertilizer application and the difficulty of mechanization, a rice fertilization spreader system，centrifugal spinning disc and flow regulating device was designed based on multi-rotor UAV for improving the mechanical performance and uniformity of UAV fertilizer application. The structural parameters of rice fertilizer plant were determined, and the effects of disc speed, flow rate, falling position angle, UAV flying speed and flying attitude on fertilizer distribution were analyzed by using EDEM software. The experimental results showed that it was beneficial to determine the width boundary by applying fertilizer in concentric circles. The width was increased with the increase of rotating speed, and the peak value of fertilizer distribution was changed from left to right. With the increase of flow rate, the uniformity presented a trend of first passing and then decreasing. UAV pitch and roll inclination had influence on fertilizer distribution, while pitch caused fertilizer to pile up in the middle, and roll inclination caused fertilizer to pile up in one side. The interaction of flow rate, UAV flight speed and centrifugal disc speed with the falling position angle had a significant effect on the uniformity of the system. When the landing angle was 40°, the disk rotation speed was 1100r/min, the flow rate was 3460 particles per second, and the UAV flight speed was 5m/s, the coefficient of variation was 8.86%. The efficiency of UAV fertilization spreader was about 12.5 times more than that of manual fertilization. This research provided a solution for the mechanized application of rice panicle fertilizer and a reference for the design of the centrifugal UAV rice panicle fertilizer spreader.
