Design And Test Of Drone Centrifugal Rice Direct Seeding Device

In this paper,a centrifugal rice seeds spreader with a ring was designed.This spreader is light and compact(1.50kg)and can be installed in a drone for rice seeding.Spreader uses centrifugal force to spread rice seeds,rice seeds will hit the ring and rebound,so that the rice seeds are non-hollow and axisymmetric Fan-blade shape distributed.We optimized the key parameter of spreader and installed it in a drone for Field trial,the result shown that the drone rice direct-seeding can reach 9295.65kg/hm~2 and verified its feasibility.We analyzed the key parameter of spreader:disc rotating speed,working height,and angle of the ring,spread uniformity CV(coefficient of variation of seeds distribution on the lateral width direction)is set as a response,EDEM and Design-expert 11.0.4 are used for experiment simulation and parameter optimization.Firstly,we run Single-factor tests to analyze the influence and the range of three factors by EDEM simulation.Secondly,for optimization,the orthogonal-regression-rotation simulation experiment with three factors was designed,the experimental data was processed by Design-expert 11.0.4,the regression model between the response and three factors was obtained.Establish response surfaces between response and factors to gain an intuitive interaction between factors,we optimize three factors and check the result by the DEM simulation as well.Thirdly,bench tests for verifying the optimization result were conducted,Lastly,the field trial was conducted with the six-rotor UAV applied the spreader,which explored the feasibility of the drone rice direct-seeding.Single-factor tests determine the range of factors:disc rotating speed 400-600(r*min-1),working height 0.5-2.5m,angle of the ring 15-35°.After the orthogonal-regression-rotation simulation experiment,the regression model and the influence of factors are obtained.The height and the disc rotating speed have a significant effect on CV,although the angle of ring effect is not significant,its squared term is highly significant and its influence on the test indicators cannot be ignored.The factors`significance on CV ranked from large to small is Height,disk rotating speed,angle of the ring.Establishing a regression equation and using Response Surface Methodology(RSM)to get the optimal level of three factors by Design-expert 11.0.4,the minimum CV is 18%when the height at 2.1 m,the disc rotating speed at 600 r/min,and the angle of the ring at26°.The CV obtained from EDEM simulation is 18.11%at optimized factors`levels.The Bench test at the Seeding Laboratory of the College of Mechanical and Electrical Engineering of Sichuan Agricultural University.According to the ASAE test standard,a14×14 boxes matrix is placed in a 2.55 m×2.55 m collection field,which is consistent with the EDEM simulation.Each box is 16cm×16cm.The bench test with 3 replicates,the CV obtained from the bench test is 19.2%,18.29%,20.80%at the optimal factors`levels,the average value is 19.43%,basically consistent with DEM simulation.Finally,the field trial was conducted on May 17th,2018 at the Sichuan Agricultural University Teaching and Research Park,located in Chongzhou City,Chengdu City,Sichuan Province.Spreader was installed below the six-rotor drone.The field trial rice seed variety is Tianyouhuazhan.The field is 42m×20m,the flying height is 2.0m,the flying speed is 2m/s,the feeding rate is 1.10kg/min.Field trial is shown that the drone rice direct-seeding can reach7705.50kg/hm2 and verified its feasibility.