蓝莓机械采摘振动参数的非线性分析与优化OA

Blueberry harvesting has significant seasonality and timeliness.Traditional manual picking methods suffer from high labor intensity and low efficiency,while mechanized vibration harvesting represents an important approach for industrialized blueberry picking.During the blueberry harvesting period,the vibration parameters of the harvesting device directly affect the picking quality.This study establishes a dynamic vibration model of the blueberry fruit-stem system based on the"stem-free"picking requirement.When the fruit and stem exhibit opposite deflection angles and vibrate in an out-of-phase state,the fruit is more easily detached from the stem connection.By analyzing the kinetic and potential energy equations of the fruit,the nonlinear free vibration control equation of the system was derived.A dedicated analysis software was developed by Python for numerical solutions to systematically study the dynamic response characteristics of the fruit-stem system.The results show that the vibration angle of the stem and the deflection angle of the fruit vary with frequency.When the frequency ranges from 32 rad/s to 82 rad/s(equivalent to 300 r/min to 520 r/min),the fruit exhibits out-of-phase vibration.Both angles decrease with increasing frequency,indicating that during harvesting,the excitation frequency should be gradually reduced as the vibration amplitude increases.Additionally,the binding force between the blueberry fruit and stem decreases sharply five days before color change and then stabilizes,with little subsequent variation.Therefore,fruit color can serve as a reliable indicator for determining the optimal harvesting time.This research provides critical data support for the design of mechanical vibration harvesting devices,helping to reduce fruit damage rates and ensure effective picking performance in practical applications.