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Enhancing Mechanical Fruit Harvesting Machines Based on Vibration Analysis.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Enhancing Mechanical Fruit Harvesting Machines Based on Vibration Analysis./
作者:	Homayouni, Taymaz.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 2021,
面頁冊數:	94 p.
附註:	Source: Dissertations Abstracts International, Volume: 83-09, Section: B.
Contained By:	Dissertations Abstracts International83-09B.
標題:	Mechanical engineering. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28775445
ISBN:	9798790640728

Enhancing Mechanical Fruit Harvesting Machines Based on Vibration Analysis.
Homayouni, Taymaz.

Enhancing Mechanical Fruit Harvesting Machines Based on Vibration Analysis. - Ann Arbor : ProQuest Dissertations & Theses, 2021 - 94 p.

Source: Dissertations Abstracts International, Volume: 83-09, Section: B.

Thesis (Ph.D.)--University of California, Merced, 2021.

This item must not be sold to any third party vendors.

Currently, fruit removal using multi-directional canopy and trunk shakers are the most widely used technique for harvesting nut trees. To develop an intelligent harvesting machine, a system needs to be developed to shake each tree optimally. Optimum mechanical harvesting machines aim to maximize fruit removal with minimum tree and fruit damage, using the least amount of energy. Maximum fruit removal requires the tree to be shaken around its natural frequency; however, the best shaking frequency is not the same for all trees. The natural frequency of a tree is a function of its morphology, size, mass, branch configurations, wood properties, and density of leaves. The natural frequency could also change during harvest. For instance, when a tree is shaken and fruit drops, the natural frequency shifts due to changes in the mass.In this work, vibration transmission in trees is studied to enhance mechanical harvesting machines while minimizing damage to the tree. Trunk shakers and canopy shakers are the most common commercial mass harvesting machines, each comes with a limitation. Further, a trunk shaker has more energy loss from tree trunk to its canopy compared to a canopy shaker.The efficiency of the commercial harvesting machines is evaluated by quantifying the energy input to the trunk and the transferred kinetic energy throughout the tree canopy. A set of wireless accelerometer sensor systems was developed and used to measure acceleration at different parts of the tree and the shaker machines. A mathematical model of vibration and force transmission throughout a pistachio tree is developed under different shaking conditions using a trunk shaker. A new method was developed to find proper shaking intensity as a function of the tree trunk size. Two canopy shakers were designed, fabricated and tested in the field for harvesting table olive trees. One design included an adjustable head, and one included a large canopy shaker for larger mature trees. It was found that a combination of canopy and trunk shaker results in the highest harvesting efficiency in olive trees.Chapter one is mainly a review of literature of different types of mechanical harvesting methods. Chapters two and three are focused on mathematical modeling of variation and force throughout a pistachio tree while shaking using a trunk shaker. Chapters four and six presents two new canopy shakers specifically designed for table olive harvesting. The effectiveness of using two shaker machines at the same time is discussed and evaluated in Chapter five.

ISBN: 9798790640728Subjects--Topical Terms:

649730
Mechanical engineering.
Subjects--Index Terms:

Canopy shaker

Enhancing Mechanical Fruit Harvesting Machines Based on Vibration Analysis.
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300 $a 94 p.
500 $a Source: Dissertations Abstracts International, Volume: 83-09, Section: B.
500 $a Advisor: Ehsani, Reza.
502 $a Thesis (Ph.D.)--University of California, Merced, 2021.
506 $a This item must not be sold to any third party vendors.
520 $a Currently, fruit removal using multi-directional canopy and trunk shakers are the most widely used technique for harvesting nut trees. To develop an intelligent harvesting machine, a system needs to be developed to shake each tree optimally. Optimum mechanical harvesting machines aim to maximize fruit removal with minimum tree and fruit damage, using the least amount of energy. Maximum fruit removal requires the tree to be shaken around its natural frequency; however, the best shaking frequency is not the same for all trees. The natural frequency of a tree is a function of its morphology, size, mass, branch configurations, wood properties, and density of leaves. The natural frequency could also change during harvest. For instance, when a tree is shaken and fruit drops, the natural frequency shifts due to changes in the mass.In this work, vibration transmission in trees is studied to enhance mechanical harvesting machines while minimizing damage to the tree. Trunk shakers and canopy shakers are the most common commercial mass harvesting machines, each comes with a limitation. Further, a trunk shaker has more energy loss from tree trunk to its canopy compared to a canopy shaker.The efficiency of the commercial harvesting machines is evaluated by quantifying the energy input to the trunk and the transferred kinetic energy throughout the tree canopy. A set of wireless accelerometer sensor systems was developed and used to measure acceleration at different parts of the tree and the shaker machines. A mathematical model of vibration and force transmission throughout a pistachio tree is developed under different shaking conditions using a trunk shaker. A new method was developed to find proper shaking intensity as a function of the tree trunk size. Two canopy shakers were designed, fabricated and tested in the field for harvesting table olive trees. One design included an adjustable head, and one included a large canopy shaker for larger mature trees. It was found that a combination of canopy and trunk shaker results in the highest harvesting efficiency in olive trees.Chapter one is mainly a review of literature of different types of mechanical harvesting methods. Chapters two and three are focused on mathematical modeling of variation and force throughout a pistachio tree while shaking using a trunk shaker. Chapters four and six presents two new canopy shakers specifically designed for table olive harvesting. The effectiveness of using two shaker machines at the same time is discussed and evaluated in Chapter five.
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650 4 $a Mechanical engineering. $3 649730
650 4 $a Agricultural engineering. $3 3168406
650 4 $a Artificial intelligence. $3 516317
653 $a Canopy shaker
653 $a Continues wavelet transform
653 $a Mechanical harvest
653 $a Olive tree
653 $a Pistachio tree
653 $a Trunk shaker
690 $a 0548
690 $a 0539
690 $a 0800
710 2 $a University of California, Merced. $b Mechanical Engineering. $3 3277529
773 0 $t Dissertations Abstracts International $g 83-09B.
790 $a 1660
791 $a Ph.D.
792 $a 2021
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28775445