Multi-angle damage analysis of apple picking based on finite element method

To address the inevitable mechanical damage during apple picking and to reduce the occurrence of irreversible damage, this paper designs a semi-envelope type picking manipulator and analyses the damage caused to the internal tissues of the apple during the gripping process. Using ANSYS finite element analysis software, an apple model consisting of peel, flesh and core was created and simulated for gripping damage analysis. The simulation results show that the maximum damage occurs on the contact surface between the apple and the gripper. The maximum stress, strain and frictional deformation were 1.24 x 1$0^{-4}$MPa, 1.27 x 1$0^{-5}$mm and 5.92 x 1$0^{-5}$mm respectively at a loading force of 50N and a vertical gripping angle, with a minimum Damage Index of 7.53. Therefore, it was concluded that the vertical gripping angle minimised the mechanical damage to the apple and achieved the best results for non-destructive gripping. The results are optimal. The results of this study provide a reference for achieving non-destructive picking of apples and provide a direction for more accurate damage prediction of fruits and vegetables.