Shaking Functionality Evaluation of Four Different Types of Citrus Canopy-Shaker Tines

The shaking functionality of different types of shaking tines for citrus canopy shakers was evaluated. Shaking responses were simulated using ANSYS/LS-DYNA, and a tractor-mounted experimental shaking machine developed for conducting field trials. Straight nylon, bent nylon, straight PVC, and straight steel tines were used as shaking rods and, in experiments, accelerometers placed at branches and fruit to detect vibrational acceleration. Simulation results indicated that tine materials affected the vibrational response of trees and the acceleration peaks of branches and limbs exerted by a steel tine were ~2.0 times as high as exerted by a nylon tine. Both simulation and experimental results demonstrated that the tine bending stiffness had a positive effect on the generated acceleration. Tree injuries caused by a straight nylon tine were much less than by other tines. The results suggested that a shaking tine should have high stiffness, but its surface should be soft. These simulation and experiment methods can be used for improving canopy shaker applications. Keywords: Citrus harvest, Canopy shaking, Shaking functionality, Trial.

Experimental Study of Vibrational Acceleration Spread and Comparison Using Three Citrus Canopy Shaker Shaking Tines

The goal of this article is to experimentally study how the vibrational acceleration spreads along the branch shaken by PVC tine, steel tine, and nylon tine for citrus canopy shaking harvesting and to compare the difference. PVC tine and steel tine have potential to be used as shaking rod for citrus canopy shaking harvesting. Nylon tine is a commonly used shaking rod. A tractor-mounted canopy shaker was developed to do the trial. The shaking frequency was set at 2.5 and 5 Hz. Experimental results showed that the vibrational acceleration at the shaking spot is not the highest. Spreading from shaking spot to the stem, it increases evidently. When spreading from stems of the outside subbranch to stems of the nearest inside subbranch, its average decrease percentage is 42%. The overall vibrational acceleration of shaking at 5 Hz is 1.85 times as high as shaking at 2.5 Hz. The overall vibrational acceleration exerted by straight PVC tine and steel tine is 1.77 and 1.97 times as high as that exerted by straight nylon tine, respectively. It is indicated that replacing nylon tine with steel tine or PVC tine helps remove the fruits inside the canopy. Replacing with steel tine is more effective than with PVC tine.

Vibration parameters assessment to develop a continuous lateral canopy shaker for mechanical harvesting of traditional olive trees

The fruit harvesting is a key factor involving both product quality and profitability. Particularly, mechanical harvesting of traditional oil olive orchards is hint by tree training system for manual harvesting, tree size and several and slanted trunks which makes difficult trunk shaker work. Therefore, canopy shaker technology could be a feasible alternative to develop an integral harvester able to work on irregular canopies. The aim of this research was to determine vibration parameters applied to the olive tree for efficient mechanical harvesting by canopy shaker measuring fruit removal efficiency and debris. In this work, a continuous lateral canopy shaker harvester has been developed and tested on large olive trees in order to analyse the operating harvester parameters and tree properties to improve mutual adaptation. Vibration amplitude and frequency, rod density and ground speed were assessed. Vibration amplitude and frequency beside ground speed were decisive factors on fruit removal efficiency. Increasing rod density has not influenced on removal efficiency although it increased significantly debris. Promising results has been reached with 77.3% of removal efficiency, applying a 28 s shaking duration, 0.17 m amplitude vibration and 12 rod drum. This result was obtained reporting 0.26 s of accumulative shaking time over 200 m/s2 resultant acceleration. The canopy shaker mechanism enabled more than 65% of detached fruits to fall vertically, facilitating catch fruit. In order to improve removal efficiency it is advisable to adapt trees, set high amplitude in the shaker mechanism, and enhance the contact time between rods and tree.