Structure Design And Experiment Of Camellia Oleifera Fruit Pick-Harvest Device With Canopy Vibration

Camellia oleifera consumes huge labor force in the process of harvesting,and camellia oleifera fruit harvesting has seriously hindered the development of camellia oleifera industry.Mechanized harvesting camellia oleifera fruit is an effective way to improve production efficiency.In this thesis,the vibration response model of camellia oleifera body and the dynamic model of camellia oleifera "fruit-branch" double pendulum were established to analyze the main factors affecting the vibration response of camellia oleifera crown under forced vibration and the conditions of camellia oleifera fruit shedding.The mechanized vibration harvesting device of camellia fruit was designed.Statics simulation was carried out by ANSYS software and dynamics analysis was carried out by Adams software.Field experiments were carried out to determine the working parameters of the vibrating camellia fruit harvester,and to verify the performance reliability of the canopy vibrating camellia fruit harvester.The main research contents and conclusions of this thesis are as follows:(1)The physical parameters related to camellia oleifera were measured and tested to obtain parameters such as contour size,elastic modulus,density and damping ratio of camellia oleifera.Three-dimensional modeling of camellia oleifera was carried out with Solidworks software.A camellia oleifera canopy vibration response model was established by simplifying the camellia oleifera tree into a cantilever beam structure.The vibration parameters and physical parameters of camellia oleifera were the main factors affecting the canopy vibration response.The first two natural frequencies of camellia oleifera were 0.42 Hz and 7.15 Hz,respectively,and the acceleration of fruit and bud shedding was 427.15 m/s2,1936m/s2,respectively.(2)A canopy vibrating camellia fruit harvesting device structure was proposed.The vibration exciting device was designed based on the working principle of the crank slider,and the arrangement mode of the vibration rod was designed according to the physical characteristics(bifurcation Angle)of camellia oleifera side branches.The vibration bars are arranged in inverted triangle structure,and the top angles are 40° and 90° respectively.Gear drive is used to realize the opening and closing action of the collection umbrella.The tilt Angle of the collection umbrella is analyzed and designed,and the tilt Angle of the collection umbrella is designed to be 15°.At the same time,analyze and check key components.(3)ANSYS simulation software was used to analyze the modal harmonious response of camellia tree body,and the vibration response of camellia tree crown was better when the vibration frequency was between 4 and 10 Hz.The harmonic response was used to analyze that camellia fruit could fall off when the amplitude of lateral branch vibration reached56.17 mm at 4～10Hz.And the key components of the canopy vibrating camellia fruit harvester are checked.The telescopic arm of the vibration device and the collection device can operate safely and reliably without causing damage due to resonance phenomenon.Adams software was used to simulate the rigid-flexible coupling between the vibration device and camellia tree,and the motion state of camellia fruit under the action of the vibration device was analyzed.At the same time,the single factor test was designed,and the simulation effect of mechanized harvesting camelia fruit was the best when the vibration height was 1000～1600mm,the vibration frequency was 8～10Hz,the vibration amplitude was 50～70mm and the vibration time was 5～11s.(4)Canopy vibrating camellia fruit harvester was developed and field test was carried out.With camellia fruit recovery efficiency and crown damage rate as evaluation indexes,vibration speed,vibration frequency,vibration amplitude and vibration time as influencing factors,orthogonal experiment Design was completed using Design-Expert software.The main factors affecting vibration recovery efficiency and crown damage rate were vibration frequency,vibration amplitude and vibration time.When the vibration height is 1370 mm,the vibration frequency is 9Hz,the vibration amplitude is 61 mm and the vibration time is 8s,the recovery rate is 89.95%,the canopy damage rate is 7.36%,and the mechanized harvesting effect of camellia oleifera fruit is the best.Field experiments showed that the average yield and crown damage rate of camellia oleifera were 87.82% and 8.09%,respectively,and the relative errors of the results were 2.31% and 0.73%,respectively.In this thesis,by studying the canopy vibration harvesting technology and integrating the equipment development of "picking + collection",the mechanized harvesting of camellia fruit with high quality and low damage can be realized to reduce the production cost,improve the production efficiency and promote the rapid development of camellia industry.