| Recently,as scientific research has been explored in depth,the health care function of Lycium barbarum in anti-oxidation,anti-aging,anti-fatigue and other aspects has been further confirmed.Its unique and rich nutritional health function is recognized gradually in western countries,and the market demand of Lycium barbarum is expanding each year.For centuries,the harvesting mechanized of Lycium barbarum has been a tough problem.Its harvesting has been artificial,which bring about low picking efficiency and high harvesting costs.With the continuous expansion of L. barbarum acreage,fruit picker will be increasingly scarce,which will be followed by rising picking costs.It’s no double that the picking of has become the bottleneck restricting the development of L. barbarum industry.Aiming at realizing the harvesting mechanization of Lycium barbarum picking,this paper vibration picking mechanism was studied,relevant basic parameters of barbarum were measured,mathematical model and finite element model were adopted to optimize picking parameters,and prototype testing machine was designed and manufactured to seek a reasonable vibration picking parameters.In this paper,relevant physical parameters of barbarum were measured.Each segment of fruiting branch stalk and fruit stem on each node were conducted mechanical parameters measurement experiments respectively,including axial compression, radial compression and radial three-point bending by using electronic equipment.Finally,other mechanical parameters were obtained by analysis and calculation according to the characteristics of stem and stalk which belong to orthotropic materials.This paper proposes that forced vibration fruiting branches were simplified to forced vibration cantilever beams model and forced vibration response of each node was solved by analytic method. MATLAB was used to optimize parameters and conduct simulation experiments.And reasonable space vector of force and the rotational speed of drive wheel under which ripe barbarum fruit were picked and the unripe and flowers couldn’t be picked were obtained.Fruiting branches with 20 nodes was chosen as the study object and the operating parameters meeting the condition were:the load exerted on the 1st,8th,14 th and 18 th nodes were 17 N 、-18.7 N 、 18.5 N and-18.9 N(signs refer to direction)respectively,the load exerted on other nodes were zero.and reasonable speed was 2 868.84 r / min≤n≤2 871.21 r / min.In this paper,the ANSYS WORKBENCH transient dynamics module was adopted to simulate and analyse the process of barbarum picked by forced vibration mode.The fruiting branch was simplified reasonably.The stress situation of barbarum fruit model after fruiting branch being exerted peak excitation force was simulated,and excitation force amplitude vector was adjusted after solving and analysis.Then the rate of picking ripe fruit α is 90%,and the largest inertial acceleration of cylinder standing for three barbarum fruit on each node was no more than 67.4m / s2.Based on the reasonable picking parameters obtained through mathematical analysis and finite element analysis on barbarum fruit picking by vibration mode,a barbarum fruit picking mechanism was designed and manufactured.Four factors and three levels orthogonal experiment and quadratic regression orthogonal design experiment whose experimental indexes were picking efficiency of ripe fruit,rate of picking ripe fruit,rate of picking unripe fruit,rate of picking followers,damage rate of picking ripe fruit and composite score were conducted to verify the reasonableness of theoretical analysis result,namely,excitation force frequency and to seek the reasonable value of picking time at each picking point,the distance between adjacent vibrating arms,the sum of vibrating arms at each row. The picking parameters level combination obtained were:the picking time at each picking point was 41.33 s,motor speed was 578.57 r / min,he distance between adjacent vibrating arms was 120 mm and the sum of vibrating arms at each row was 10. |
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