Design Of UAV Fertilization Device And Its Application And Evaluation On Rice Panicle Fertilizer

Aiming at the problems of low efficiency and high difficulty in mechanization of rice ear fertilization,a special fertilization device for UAV was designed based on UAV platform.Based on the working process,mechanical structure and movement characteristics of fertilizer particles,EDEM software was used to simulate the process of fertilizer spreading and optimize the working parameters of the fertilizer spreading device.The simulation results are verified by bench test.The economic benefit,work efficiency and rice growth status of unmanned aerial vehicle(UAV)and artificial fertilization were compared and analyzed by field experiment.The main research results are as follows:The mechanical structures such as battery cabin,fixing frame,load-bearing slide rail,flow control unit,centrifugal disc,buckle and fertilizer box are designed.Among them,the structure of the centrifugal disk is small and highly adaptable to high rotation speed.The curved surface fertilizer plate can change the movement direction of fertilizer particles to adapt to the UAV wind field.Integrated flow control unit,stable flow control,light structure;The pull-out structure makes fertilizer filling more efficient.EDEM software was used to analyze the movement characteristics of fertilizer particles in the three stages of fertilizer box,centrifugal disk and air,as well as the working process and principle of the fertilizer spreading device of UAV.The results of single factor simulation show that the width increases with the flight height and the centrifugal disk speed.The influence of flight height on the distribution uniformity was small,and the rotation speed of centrifugal disk was 1000～1300 r/min.The falling position Angle has a great influence on the uniformity of fertilizer distribution,and the uniformity of fertilizer distribution is better at 35°～55°.The pitch Angle has more influence on the uniformity than the pitch Angle.Four factors five levels quadratic orthogonal regression rotary center combination simulation test results show that the flow,speed and centrifugal plate speed respectively and the position Angle of fall into three interactions,spreader uniformity of device have a significant impact.The order of the influence of each factor on the uniformity from large to small is as follows:Angle of falling position,rotation speed of centrifugal disk,flow rate and flight speed;When the falling position Angle is 40°,the centrifugal disk speed is 1100r/min,the flow rate is 3460 pieces/s,and the flight speed is 5m/s,it is the optimal parameter combination,and the coefficient of variation is the smallest,which is 8.86%.In the bench test under the optimal combination,the average coefficient of variation is 9.74%,which is little different from the simulation results,indicating that the simulation results are reliable.The results of field experiments showed that the nitrogen dry matter production efficiency and nitrogen rice production efficiency of unmanned aerial vehicle(UAV)fertilization were higher than that of artificial fertilization,and the nitrogen uptake rate of100kg seeds was slightly higher than that of artificial fertilization for two years.The yield was slightly higher than that of artificial fertilization,and the working efficiency was about12.5 times that of artificial fertilization.The unit cost was 18.45 yuan/hm~2 less than that of artificial fertilization.UAV application of rice spike fertilizer has advantages.