Simultaneous trunk and branch shaking in an over-the-row olive harvester

Abstract

Harvesting in intensive olive orchards is usually performed with trunk shakers. Many challenges remain both to the implementation of integral harvesting systems and to improving their detachment efficiency without a dependence on manual labour. This work develops a prototype over-the-row harvester that incorporates two harvesting systems which can work simultaneously: a trunk shaker and two canopy shakers. The objective is to characterise the dynamic effect of each system and determine the best configuration for efficiency and damage control regarding feasibility of use. The trunk shaker in isolation has a predominantly dynamic effect with very high acceleration values that slightly increased with the addition of the canopy shaker systems. In all cases, acceleration transmissibility between the trunk and branches amplified, and increased between 8% and 17% at low and high frequencies, respectively, when the trunk shaker worked in conjunction with the canopy shakers. The increase in resultant acceleration did not correlate with the increase in detachment percentage or with the amount of damage due to the impact generated by the canopy shaker. However, this effect is observed in the vibration pattern generated by both systems. Configuration of the trunk shaker at 21.4 Hz and the canopy shakers at 3.6 Hz reported detachment efficiencies higher than 85% and damage less than 3 kg per 100 kg of fruit. The results show a feasible alternative to the harvesting systems habitually employed in intensive olive orchards, which require tree training adapted to the type of machine in order to improve efficiency and reduce damage.