Identification of vibration frequency, acceleration, and duration for efficient olive harvesting using a trunk shaker

In this study, an orbital trunk shaker was employed to determine the optimal frequency and shaking time that maximizes the fruit removal percentage of olives. The vibration imparted from the shaker to the trunk and the weight of the fruit removed were determined. The resulting acceleration was linearly correlated with the frequency and acceleration transmitted to the trunk by the clamp and decreased by more than 53%, probably due to the additional rubber covering on the clamp that was used to reduce the risk of damage to the bark. The frequencies that maximized the fruit removal percentage were 25 Hz for the Frantoio and Picholine cultivars, 23 Hz for the Leccino cultivar, and 27 Hz for the Cima di Melfi cultivar, and the tri-dimensional acceleration value measured on the trunk ranged from 70.41 to 99.25 m s-2. The fruit removal percentage versus the shaking time exhibited a sigmoidal trend, and the optimal shaking time was 8 s for the Frantoio and Cima di Melfi cultivars and 6 s for the Leccino and Picholine cultivars. Improving the mechanical and hydraulic characteristics of the shaker is necessary to achieve the optimal vibration conditions.