Design And Research Of Multi-channel Camellia Oleifera Fruit Layered Picking Device

Aiming at the technical problems of camellia oleifera fruit picking machine such as low picking efficiency,high damage rate of flower bud and difficulty in continuous operation of existing picking machinery in camellia oleifera forest land with complex terrain,this paper analyzed the development status of forest fruit harvesting equipment at home and abroad and the domestic research status of camellia oleifera picking equipment.The biomechanical characteristics of camellia oleifera fruit,flower bud and physical characteristics of camellia oleifera branches were measured,and a multi-channel camellia oleifera fruit layered picking device was designed.The virtual prototype model of multi-channel camellia oleifera fruit layered picking device was established in Creo 3D software.The ADAMS software was used to simulate and analyze the contact collision between camellia oleifera fruit and picking device,and the ANSYS software was used to simulate and analyze the contact collision between flower bud and picking device.A physical prototype was developed for outdoor picking test,and the picking rate of camellia oleifera fruit and damage rate of flower bud under the optimal parameters combination were determined by outdoor verification test.The research results can provide a reference for the design of the camellia oleifera fruit picking device.The specific points are as follows:(1)The separation force between camellia oleifera fruit,flower bud and fruit branch was measured by digital explicit tension meter.The results showed that when the angle between the direction of exerting tension and the long axis of camellia oleifera fruit and flower bud were 0°,30°,60° and 90°,the pulling force of camellia oleifera fruit and flower bud decreased with the increase of the angle,and presents a certain linear relationship.The pulling force of flower bud in the same direction was less than that of camellia oleifera fruit.The thickness of single camellia oleifera branch and the angle between camellia oleifera branch and horizontal ground were measured.The results showed that the thickness of single camellia oleifera branches was mainly distributed between 260 mm and320mm,and the angle between camellia oleifera branches and horizontal ground was mainly distributed between 15° and 35°.(2)The picking model of the collision between camellia oleifera fruit and rubber rollers was established,the characteristics of camellia oleifera fruit shedding were analyzed,and the main factors affecting the fall of camellia oleifera fruit were obtained.On this basis,according to the biomechanical properties of camellia oleifera fruit,flower bud and physical properties of fruit branches,the layered picking plan of camellia oleifera fruit was determined and a multi-channel camellia oleifera fruit layered picking device was designed.The overall structure design of the picking device was completed and the 3D model of the picking device was established in Creo software.(3)The rigid-flexible coupling simulation analysis of the collision and shedding process between the camellia fruit and the rubber roller was carried out by Adams software.The simulation results showed that the centroid acceleration of camellia oleifera fruit increased with the increase of rubber rollers speed and rubber rollers diameter,and decreased with the increase of rubber rollers spacing.The value of stress and strain at the collision contact between camellia oleifera fruit and the rubber rollers increased with the increase of rubber rollers speed and rubber rollers diameter,and decreased with the increase of rubber rollers spacing.On this basis,the ANSYS Workbench software was used to simulate analyze the damage law of the different rubber rollers speed,different rubber rollers spacing and different rubber rollers diameter on flower bud damage.The results showed that the values of equivalent stress and equivalent strain increased with the increase of rubber rollers speed and rubber rollers diameter,while the values of equivalent stress and equivalent strain increased first and then decreased with the increase of rubber rollers spacing.(4)Based on the theoretical research,the processing and production of physical prototype was completed.Three factors and three levels of quadratic orthogonal rotation combination test method was used to carry out the test,with the speed of rubber rollers,spacing of between rubber rollers and diameter of rubber rollers as the test factors,and the picking rate of camellia oleifera fruit and the damage rate of flower bud as the evaluation indexes.Experimental results showed that the successive factors affecting the picking rate of camellia oleifera fruit and the damage rate of flower bud were speed of rubber rollers,distance between rubber rollers and diameter of rubber rollers.The optimal combination of parameters were obtained when the speed of rubber rollers was 130mm/s,the spacing between rubber rollers was 21 mm,and the diameter of rubber rollers was 30 mm.The optimal combination of parameters was verified by outdoor picking experiments.Final results showed that the average picking rate of camellia oleifera fruit was 95.68% and the average damage rate of flower bud was 3.92%.