Abstract:

Objective: To achieve efficient and low-damage vibration harvesting of wolfberries, this study investigates the vibration response in fruit-bearing branches of wolfberry. Method: By establishing a dynamic model of wolfberry-bearing branches, the acceleration decay curve and biomechanical characteristic parameters of the branches in a free vibration state were measured. The equivalent stiffness coefficient, equivalent damping coefficient, and equivalent mass of the branch dynamic model were calculated. The vibration characteristics of external forces at different positions on the branches were studied to determine the optimal vibration position. Matlab software was used to simulate the dynamic response of the branches, and corresponding field vibration tests were conducted for validation. Result: During the vibration process, the kinetic energy variation of branches reflects their motion velocity changes. The magnitude of kinetic energy is positively correlated with the vibration harvesting effect, and the branch kinetic energy can serve as an evaluation index for the response effect of vibration positions. Simulation results demonstrate that vibrating at different branch positions leads to significant differences in corresponding kinetic energy changes. When the excitation point is located at the middle-rear position of the branch, the maximum kinetic energy of the branch reaches 27.06 J, corresponding to a ripe fruit harvest rate of 92.17%, indicating the optimal vibration effect. Field trials are largely consistent with the simulation results, confirming the optimal vibration position for fruiting wolfberry branches. Conclusion: Kinetic energy is an effective indicator for evaluating the vibration effect of branches. The vibration effect is optimal when the excitation point is located at the middle to rear part of the branches. This study provides a basis and reference for precise multi-point vibration.

Key words: wolfberry, fruit-bearing branch, kinetic energy, vibration position, mass-spring-damping system