Digital Design And Optimization Of High Altitude Picker

In order to improve the harvesting efficiency of betel nut,reduce the cost of picking,and achieve mechanized picking of betel nut,a high-altitude picking truck was designed by adapting digital designing technique.The main research work is as follows:（1）The research status of digital design for the picking machinery in agricultural orchards was explained.The characteristics of betel nut and betel nut trees were outkined,the working range and functions of the picking truck were analyzed;A high-altitude picking truck structure composed of a crawler,a scissor lifting platform,a rotary table,a telescopic arm,and an end effector is proposed according to the scope and function of its operation,the design calcultion and 3D modeling of each part is completed;The anti-overturning performance of high altitude picking truck was analyzed and verified,the strength and stiffness of the telescopic arm and the scissors fork were checked and the verification results of the single-arm scissors were verified by finite element simulation software.（2）Kinematic simulations and Multi-body dynamics simulations of high altitude picking truck were carried out respectively with Solidworks and Adams.Among them,kinematic simulations mainly include interference checking,verification of the displacement and the operating range of the kinematic pair;Dynamic simulations mainly include dynamic simulation of hoist cylinder,luffing cylinder,telescopic cylinders,and modal analysis of gear bracket.Kinematics simulation can improve the3D model and prove the validity of the trajectory and the scope of operation,the reliability of the hydraulic cylinder movement was verified with comparing the hydraulic cylinder force obtained from the dynamics simulation and foregoing calculation results,the correctness of the aforementioned motor selection was verified with modal analysis.（3）The theory of multi-objective optimization and the theory of NSGA-II multi-objective genetic algorithm were outlined.The position of variable-width hinge was optimized with Isight and NSGA-II.The optimization results show that the force of the variable cylinder is reduced by 28.8%,and the torque of the telescopic’s boom section C₂D₁ is reduced by 16.5%.In summary,a high altitude picking truck was designed based on digital design method,the reliability of structure of high altitude picking truck was analyzed,the accuracy of picking motion is verified by kinematic simulations and dynamic simulations,a better luffing structure was obtained with a multi-objective optimization method.Therefore,high-altitude picking truck have important reference significance and guidance for betel nut fruit and similar fruit picking machines.