FORCE DISTRIBUTION ON ORANGES AT DIFFERENT LOCATIONS IN THE TREE HARVESTED WITH A CANOPY SHAKER
Currently, continuous canopy shakers are the most widely used type of citrus mechanical harvesting machines in Florida. Better understanding the interaction of harvesting machines and tree canopy during harvest, by measuring and analyzing the force distribution of fruit in the canopy under real harvesting conditions, could help to improve the existing canopy harvesting machines. The goal of this study was to measure the force experienced by different sizes of oranges in different parts of the canopy during harvest with a tractor driven, canopy-shaking harvesting machine. Multi-node, ZigBee-based wireless sensors equipped with three-axis accelerometer sensors were developed for this study. These sensors were placed on many fruits of different sizes and locations in tree canopies. These tests were conducted in trees in different groves. The force experienced by these fruits was measured, and the force distribution within the tree canopy was analyzed. The force exerted on the fruit was dependent on the location of the fruit in the canopy. The average maximum detach¬ment force for 'Hamlin' was 25.3 kg-f and 23.9 kg-f for 'Valencia' oranges. In addition to the amount of force, the duration for which there is significant force is an impor¬tant factor that determines fruit removal. The distribution of force over time on each fruit was found to be a Gaussian distribution. The duration for the significant force was taken to be the time interval for the first standard deviation interval.
Udumala, S.K., Ehsani, R., Bora, G. and Hebel, M. (2009). FORCE DISTRIBUTION ON ORANGES AT DIFFERENT LOCATIONS IN THE TREE HARVESTED WITH A CANOPY SHAKER. Acta Hortic. 824, 141-146