Design And Optimization Of Fruit Vibration Harvesting Mechanism Based On Epitrochoid

China's current fruit production and fruit consumption rank first in the world.With the expansion of fruit planting area,the market demand for orchard mechanization continues to increase.The labor required for the whole fruit harvest takes up at least 15%of the entire production process of the orchard.The mechanized harvesting of the fruit can not only pick the efficiency,save the labor cost,but also reduce the fruit damage rate.Therefore,it is of great significance to improve the mechanized harvesting of fruits.This topic aims to further improve the efficiency of harvesting of vibrating fruit harvesters and reduce the damage impact on fruit trees during vibration.Therefore this paper first establishes a fruit tree model,compares the different types of non-circumferential excitation loads to simulate the dynamics of the fruit tree model,and designs the fruit vibration harvesting mechanism based on the Epitrochoid according to the simulation results,and finally conducts the field vibration acceleration response test to verify The actual harvesting effect of the fruit vibration harvesting mechanism based on the Epitrochoid.According to the above ideas,The research content of the thesis is as follows:(1)In order to facilitate the study of the vibration characteristics of fruit trees,this paper simplifies it into a mass-elastic element system.A four-degree-of-freedom fruit tree dynamics model is established,which can better reflect the vibration of fruit trees.The modal analysis and harmonic response analysis of the fruit tree model were carried out using the finite element software ANSYS.The results show that:(1)The response deformation of the fruit trees at different excitation frequencies is not the same,generally the branch torsion and bending deformation.(2)It is found through the statistical harmonic response curve that the frequency of the excitation vibration is 4 Hz?14 Hz.The shaking frequency can achieve a better shaking effect.The theoretical basis for the harvesting device is provided by establishing a fruit tree dynamics model and simulation experiments.(2)Firstly,the existing fruit tree excitation form is analyzed.It is found that the non-circumferential excitation can stimulate the fruit tree more effectively to make the fruit tree produce an overall response.By introducing the ANSYS fruit tree model into ADAMS and performing different types of non-circumferential excitation to stimulate the fruit tree model,the non-circumferential excitation uses the cyclone curve to excite the fruit trees,and compares the excitation response of different types of hypotrochoid and epitrochoid excitation loads to the fruit trees.The acceleration of the fruit trees when different trajectories are shaken and the acceleration coefficient of the statistical test points,and finally the optimal trajectory with more concave but not close to the circle is selected as the incentive method for designing the fruit vibration harvesting mechanism.`(3)According to the simulation results of fruit tree dynamics,considering the achievability of the mechanism of the trajectory,designing the fruit vibration harvesting mechanism based on the Epitrochoid,firstly introduces the mechanism composition and working principle of the fruit vibration harvesting mechanism based on the Epitrochoid.The organization is mainly composed of a 5R mechanism,a bucking mechanism,a power transmission part,and a box.Then the kinematics analysis of the mechanism and the trajectory planning of the mechanism are used to plan the variation of the input angle of the servo motor with time.Finally,the kinematics simulation and dynamics simulation of the mechanism are carried out to solve the displacement,velocity and acceleration of the output end of the mechanism and the torque of the input drive rod,to verify the trajectory and select the motor.(4)According to the determined optimal trajectory and the design of the fruit vibration harvesting mechanism,the processing and assembly of the prototype was completed.The prototype is tested and tested.The software and hardware of the control system are set to realize the motion control of the servo motor by the single chip microcomputer.Finally,the outdoor fruit tree vibration response test was carried out,and three sets of outdoor tests were carried out to measure and count the average acceleration of 20 test points when vibrating fruit trees under different trajectories.The results show that when the 3/1 branch epitrochoid trajectory 5?3/1branch hypotrochoid trajectory 5?5/1 branch hypotrochoid trajectory 5 is excited,The average vibration acceleration and coefficient of variation of the tree are 10.15 m/s~2 and 0.48,13.31 m/s~2and 0.57,15 m/s~2 and 0.78.It is verified that the 3/1 branch epitrochoid trajectory 5 can achieve the overall excitation effect on the fruit tree and satisfy the output large shaking excitation when the fruit tree is excited.It is proved that when different spinner lines excite the fruit trees,the more concave in the trajectory line,the larger the average acceleration generated when the fruit trees are excited,but the overall excitation effect will be worse.