Fluid-structure Coupling Simulation And Experimental Study Of Air-suction Picker

Air suction pick up machine has the advantages of high picking efficiency,low broken fruit rate,can effectively reduce the strength of artificial pick up,can be used for picking up jujube,In this paper,the model of sour jujube and jujube leaves was modeled based on multi-perspective 3D reconstruction technology.PhotoScan 3D image reconstruction software and SIFT algorithm were used to detect feature points and feature vectors,and feature matching was carried out to generate original point cloud data.The threshold method and scan line method were used to delete noise points and redundant points to obtain dense point clouds.Through meshwork and texture mapping,the three-dimensional mesh was transformed into a three-dimensional mesh,and then the curve fitting,surface reconstruction,point cloud and other operations were carried out to obtain the three-dimensional models of jujube and jujube leaves.According to the physical characteristics of sour j ujube,the suspension speed of sour j ujube is calculated,and the main structural parameters of the air suction type picker are designed.Fluent software was used to simulate the fluid domain of the air suction picker.The pressure cloud and velocity vector cloud were compared under different pipe diameters and flow rates to observe the change of pressure drop and velocity vector in the fluid domain,and the change law of pipe diameter,flow rate and pressure drop was studied.Based on the gas-solid coupling simulation of EDEM-Fluent,the picking process of ziziphus jujube was simulated and analyzed,and the cloud images of ziziphus jujube particles under different pipe sizes and flow rates were obtained.The results showed that with the increase of flow rate,the speed of jujube increased,the collision force gradually increased,and the separation of jujube leaves was obvious.Using the response surface methodanalysis of pipe diameter,flow rate and quality of zizyphus jujube three factors of zizyphus jujube speed and the influence of the collision force,found that the flow is the main factors influencing the speed of zizyphus jujube,pipe diameter are the main factors influencing the collision force,obtains the best zizyphus jujube an d structural parameters of the collecting machine,experimental platform,air suction acid jujube collecting machine set for laboratory test,Including bellows,sink cavity,grating,centrifugal fan and power supply,etc.to measure picking efficiency and breakage rate.Comprehensive theoretical analysis,simulation and parameter optimization of pipe diameter and flow rate,the best pipe diameter 0.11m,the best flow 0.28m3.s-1,the pick up efficiency of sour jujube 211kg.h-1,the broken rate of sour jujube is less than 5%,the pick up rate of sour jujube is higher than 90%,meet the requirements of picking up sour jujube.The air suction type picker can not only reduce the cost of picking-jujube,shorten the picking-cycle of picking-jujube,but also improve the efficiency of picking up.The research results have important reference value for the research of picking up fruit in the landing forest.